6 International Conference on Microbial ... - MiCom 2017

6th International Conference on Microbial Communication for Young Scientists 20 - 23 March 2017 • Jena, Germany

Table of Contents Welcome to MiCom 2017

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About JSMC

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About CRC AquaDiva

4

MiCom 2017 organizing committee

5

Conference programme

6

Keynote speakers

11

Workshops

15

Poster session

16

Non-scientific programme Welcome reception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conference dinner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Social activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Talk abstracts Keynotes . . . . . . . . . . Environment session . . . Pathogenesis session . . . Chemical ecology session Natural products session . Systems biology session .

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24 24 27 31 36 38 40

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46 46 51 63 68 73

Poster abstracts Environment . . . Pathogenesis . . . Chemical ecology Natural products Systems biology . Imprint

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1

Welcome to MiCom 2017

Dear colleagues, friends and guests, dear members of the Jena School for Microbial Communication, it is my great pleasure to welcome you to Jena! A city which not only inspired numerous philosophers, writers and entrepreneurs in biotechnology and optical technologies but which also became a home for many microbiologists. In recent decades, Jena with its Friedrich Schiller University and Leibniz, Max Planck, Fraunhofer and Helmholtz Institutes has evolved as a major player in microbial research. This success has been made possible especially by the cooperative working atmosphere extending across the disciplinary and institutional boundaries. Microbiologists, physicians, chemists, bioinformaticians, physicists, photonic scientists and other professionals come together to work on microbial communication. This is institutionalised by our flagship, i.e., the Excellence Graduate School Jena School for Microbial Communication, which was founded in 2006 in the frame of the excellence initiative. Due to the extremely high motivation of our doctoral and postdoctoral researchers the MiCom student’s conference series is exclusively organised by doctoral researchers, which gives the conference a unique atmosphere. I am very grateful to the organisation committee to put together such an exciting programme. Here in Jena, you will find a lively and - particularly important - collegial and friendly environment, which will inspire you to think outside the box! I wish you a pleasant MiCom Conference 2017 with many good discussions and conversations! with my best regards,

Axel Brakhage Speaker, Jena School for Microbial Communication

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Dear MiCom participants, We are delighted to welcome you to the “6th International conference on Microbial Communication for Young Scientists” (MiCom 2017) in the beautiful city of Jena. Established in 2010, MiCom is a unique conference organized by PhD students of the Jena School for Microbial Communication (JSMC) and the Collaborative Research Centre AquaDiva. The goal of MiCom is to create a platform that fosters interdisciplinary discussion between accomplished researchers and young scientists in the field of microbial communication. In MiCom 2017, we have prepared a dynamic and diverse scientific program for you. MiCom comprises five thematic areas under the umbrella of microbial communication. These areas are split into nine sessions led by a roster of respected and internationally renowned speakers. In addition, we offer ten workshops covering areas related to scientific research, soft skills, and industry; the workshops offer participants the opportunity to meet and converse with the speakers on a more personal basis. Aside from the excellent scientific program, we invite you to join us for unique and memorable networking events, where you can rub shoulders with experts and opinion leaders in the field of microbiology. Your participation and support have made MiCom 2017 a record-breaking event, hosting over 200 participants from 32 countries. We welcome you to Jena and wish you an enjoyable and memorable conference. Yours sincerely, The Organizing Committee of MiCom2017

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About JSMC The Jena School for Microbial Communication (JSMC) is a structured, interdisciplinary PhD training programme based on top-level research. It brings together scientists from different fields by integrating three thematically related Research Training Groups. The main objective of the JSMC is to decipher all the facets of microbial communication, which encompasses how microorganism communicate amongst each other, with higher organisms and with their abiotic environment. This is based on the exchange of various chemical molecules that have an extremely wide range of possible applications as industrially relevant natural products, for instance novel antibiotics. The JSMC successfully integrates such diverse disciplines as biology, chemistry, medicine, pharmacy, biotechnology, geology, mathematics, physics and computer science. The JSMC network consists of numerous institutes of the Friedrich Schiller University Jena, seven non-university research institutions and 11 partner companies. It provides excellent conditions for cooperative research combining basic science and industrial application. The JSMC doctoral researchers complete an ambitious training program that will employ the latest transdisciplinary state-of-the-art research methods. The JSMC currently encompasses 150 doctoral researchers from 33 different countries supervised by a faculty of 70 principal investigators. Over 300 high-impact publications in international high-ranking journals have been published from within the JSMC network since its inception, and 80 doctoral researchers were able to successfully complete their PhD already.

About CRC AquaDiva The Earth’s Critical Zone (CZ) is the thin, living, and permeable layer that connects the atmosphere with the geosphere, and provides the living environment for most terrestrial biota. Humans live in the CZ, and benefit from the vital services it provides, including clean water resources. Pollution, land-use, and climate change increasingly alter the surface compartments of the CZ, but we have not yet explored this part of the earth enough to fully understand the consequences for the subsurface, the zone beginning below the highest density of plant roots and extending into the aquifers. The principle aim of the CRC AquaDiva is to increase our understanding of the links between surface and subsurface, especially how organisms inhabiting the subsurface CZ reflect and influence their physical, ecological, and geochemical environment, and affect water and matter transiting the CZ. To achieve this, we have constructed a novel infrastructure platform, the Hainich Critical Zone Exploratory (CZE), to study how water and gas fluxes link surface vegetation and soils under different land management to aquifer complexes. The Hainich CZE was established in an alkaline geological setting and encompasses two main aquifer assemblages along a 6 km transect in limestone and marlstone rock, spanning forest, pasture and agricultural land-uses. Our interdisciplinary team applies new tools from the fields of biology, chemistry, geoscience, and informatics to document the state and function of the subsurface: who is there, what are they doing, and how it matters.

4

MiCom 2017 organizing committee

Theresia Conrad

Naim Al-Zaben

JSMC, Hans Knöll Institute Systems biology session, advertisement, sponsoring, catering

JSMC, Hans Knöll Institute Systems biology session

Iuliia Viediernikova ILRS, JSMC, Hans Knöll Institute Chemical ecology session, management, finances, sponsoring

Robert Barnett JSMC, Hans Knöll Institute Chemical ecology & Natural products sessions, schedule, sponsoring

Wolfgang Vivas JSMC, Hans Knöll Institute Pathogenesis session

Jens Esken ILRS, JSMC, Friedrich Schiller University Chemical ecology, conference dinner, sponsoring, funding, secretary

Tina Müller JSMC, Jena University Hospital Pathogenesis session, venue, sponsoring

Sofía Siscar Lewin JSMC, Hans Knöll Institute Pathogenesis session, advertisement, sponsoring, catering

Sarah Irmscher

Swatantar Kumar

JSMC, Hans Knöll Institute Pathogenesis session, sponsoring, advertisement

AquaDiva, IMPRS-gGBGC, Friedrich Schiller University Environment session, social media, advertisement

Michael Gaspar AquaDiva, Friedrich Schiller University Environment session, management, website, registration, venue, IT support, booklet

Carl-Eric Wegner AquaDiva, Friedrich Schiller University Environment session, finances

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Conference programme Monday, March 20th 09:00 - 10:30

Registration

10:30 - 11:00

Welcome address

CHEMICAL ECOLOGY SESSION I (Chair: Iuliia Viediernikova) 11:00 - 12:00 Keynote - Prof. Jon Clardy Lessons from the microbial metabolites that regulate multilateral symbioses (p. 24) 12:00 - 12:15

Nora Adam Small changes with big consequences: variation in a key gene structures herbivore communities and determine plant performance (p. 36)

12:15 - 12:30

Hsiao-Ying Cheng Ratiometric gas reporting: a new approach to monitor microbial cell-cell signaling in soils (p. 36)

12:30 - 12:45

Group photo

12:45 - 14:00

Lunch break

NATURAL PRODUCTS SESSION (Chair: Robert Barnett) 14:00 - 15:00 Keynote - Prof. Sarah O’Connor Harnessing the chemistry of plant natural product biosynthesis (p. 24) 15:00 - 15:15

René Benndorf Functional and chemical analysis of Actinobacteria associated with fungus-growing termites (p. 38)

15:15 - 15:30

Martin Klapper Pyreudiones: novel bacterial amoebicides produced by a monomodular nonribosomal peptide synthetase (p. 39)

15:30 - 15:45

Lisa Mahler pL-Droplets as novel vessels for ultra-high throughput cultivation and screening of microbial cells (p. 39)

15:45 - 17:45

Coffee break & POSTER SESSION I (even numbers)

WORKSHOP SESSION I 17:45 - 18:45 Jon Clardy Small molecules and sexual commitment (Room 206) Oliver Kurzai & Marc Thilo Figge Cooperation beyond disciplines - How Systems Biology can really work! (Room 207) Sarah O’Connor How to elucidate biosynthetic pathways in plants (Room 208) 19:30 onwards

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Welcome Reception at the Haus auf der Mauer (p. 22)

CONFERENCE PROGRAMME

Tuesday, March 21st PATHOGENESIS SESSION I (Chair: Wolfgang Vivas) 09:00 - 10:00 Keynote: Prof. Oliver Kurzai Host-pathogen interplay in invasive fungal infection (p. 24) 10:00 - 10:15

Philipp Kämmer Fingerprinting of Candida spp. blood infections (p. 31)

10:15 - 10:30

Mohamed Abdelwahab Hassan Towards understanding the intraphagocytic long term survival of Lichtheimia corymbifera (p. 31)

10:30 - 10:45

Nadine Reiher Candida albicans battle against Dectin-1 and Dectin-2 host-mediated immune response (p. 32)

10:45 - 11:00

Nicole Engert Hypoxia influences the C. albicans - enterocyte interaction (p. 33)

11:00 - 11:30

Coffee break

CHEMICAL ECOLOGY SESSION II (Chair: Jens Esken) 11:30 - 12:30 Keynote: Prof. Jonathan Gershenzon Microbially mediated associations between conifers and conifer insects (p. 25) 12:30 - 12:45

Stefan Kruse Syntrophic interactions in a dechlorinating co-culture of Sulfurospirillum multivorans and Dehalococcoides mccartyi (p. 37)

12:45 - 13:00

Chhana Ullah Defense signaling in poplar (Populus sp.) against biotrophic rust fungus Melampsora larici-populina (p. 37)

13:00 - 14:00

Lunch break

ENVIRONMENT SESSION I (Chair: Carl-Eric Wegner) 14:00 - 15:00 Keynote: Prof. Christa Schleper Ecology, physiology and evolution of ammonia oxidizing Archaea (p. 25) 15:00 - 15:15

Martina Herrmann Be small and find a host – do oligotrophic subsurface environments support symbiotic and parasitic relationships among microorganisms? (p. 27)

15:15 - 15:30

Tilottama Mazumdar The dominating bacteria in the gut of Spodoptera littoralis (p. 28)

15:30 - 15:45

Katja Burow Microbially-induced release of elements/radionuclides (p. 30)

15:45 - 17:45

Coffee break & POSTER SESSION II (odd numbers)

WORKSHOP SESSION II 17:45 - 18:45 Zoltán Cseresnyés Microscopy imaging; How to produce good images? (Room 206) Sascha Brunke How not to lie with statistics (Room 207) Susan Trumbore How to get your paper published (or rejected) (Room 208) 19:30 onwards

Conference Dinner at the Landgrafen (p. 22)

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Wednesday, March 22nd SYSTEMS BIOLOGY SESSION I (Chair: Theresia Conrad) 09:00 - 10:00 Keynote: Prof. Manja Marz Fight infections in silico (p. 26) 10:00 - 10:15

Thomas Wolf From dual RNA-Seq data to inter-species gene regulatory networks: computational prediction of molecular host-pathogen interactions (p. 40)

10:15 - 10:30

Natalie Töpfer Insights into the mode of action of sepsis biomarker CAAP48 in human neutrophils using Raman spectroscopy (p. 41)

10:30 - 10:45

Patricia Sieber Alternative splicing of Aspergillus fumigatus during interaction with human neutrophils (p. 41)

10:45 - 11:00

Francesco Pezzini Transcription factor – histones interplay in regulation of stress response and secondary metabolism (p. 42)

11:00 - 11:30

Coffee break

ENVIRONMENT SESSION II (Chair: Swatantar Kumar) 11:30 - 12:30 Keynote: Prof. Susan Trumbore Using C isotopes to scale from microbes to landscapes (p. 26) 12:30 - 12:45

Patricia Geesink Love and Hate in the Subsurface - Growth Promotion and Inhibition induced by Groundwater Bacteria (p. 29)

12:45 - 13:00

Ali Nawaz Are subsurface fungal communities reflection of surface fungal communities? (p. 29)

13:00 - 13:15

Sebastian Pietschmann Phytoremediation: soil microbes and their activity (p. 30)

13:15 - 13:30

Silviu Bercea Microbial monitoring in an underground environment – aspects from Romanian show caves (p. 28)

13:30-14:30

Lunch break

WORKSHOP SESSION III 14:30 - 15:30 Pierre Stallforth Applying for a Postdoc in the US and Abroad (Room 206) Nicolas König Biologists in Industry - An Insight into Eppendorf (Room 207) María García Altares Mass Spectrometry: Mapping Microbial Interactions (Room 208) Manja Marz MiCom: In Silico (Room 209)

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15:30 onwards

Social activities (p. 23) Guided city tour / Planetarium / Hiking tour

19:00 onwards

Science slam at the Kulturbahnhof (p. 23)

21:30 onwards

Pub crawl (p. 23)

CONFERENCE PROGRAMME

Thursday, March 23rd PATHOGENESIS SESSION II (Chair: Sarah Irmscher) Keynote: Prof. Gordon Brown 09:00 - 10:00 C-type lectins in Immunity (p. 26) 10:00 - 10:15

Annika Franke The role of secreted Ece1 peptides in Candida albicans – macrophage interaction (p. 33)

10:15 - 10:30

Hana Krutinova The role of auxins in the interaction of plant and a hemibiotrophic fungal pathogen Leptosphaeria maculans (p. 34)

10:30 - 10:45

Sven Rudolphi Candida albicans colonization of the murine gut does not depend on filament maintenance and cell damage (p. 35)

10:45 - 11:30

Coffee break

SYSTEMS BIOLOGY SESSION II (Chair: Naim Al-Zaben) Keynote: Dr. Jaber Dehghany 11:30 - 12:30 Early markers determine the formation of mushroom-like biofilms by Pseudomonas aeruginosa (p. 27) 12:30 - 12:45

Marco Blickensdorf Agent-based modeling of early Aspergillus fumigatus infection in mice (p. 42)

12:45 - 13:00

Annika Rudat Spatiotemporal analysis of synthetic microbial communities at the single-cell level in microfluidic interaction compartments (p. 43)

13:00 - 13:15

João Saraiva Discriminating fungal from bacterial infections by a consistent transcriptomics signature (p. 43)

13:15 - 13:30

Maria Prauße Predictive infection modeling of Candida albicans immune escape in human blood (p. 44)

13:30 - 13:45

Stefan Lang Microbial camouflage by Candida albicans using human factor H - a numerical model (p. 76)

13:45 - 14:30

Poster prizes Closing remarks

9

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KEYNOTE SPEAKERS

Keynote speakers Prof. Jon Clardy Harvard Medical School, Boston, United States After his B.S. from Yale University in 1964, he completed his Ph.D. in chemistry at Harvard University. A faculty position in the Chemistry Department at Iowa State University was followed by joining the Chemistry Department at Cornell University in 1978, where he stayed until 2002. He then moved to the Biological Chemistry and Molecular Pharmacology Department at Harvard Medical School where he is currently the Hsien Wu and Daisy Yen Wu professor. His research focuses on the isolation and structural characterization of natural products, and currently investigates the role of biologically active small molecules in mediating symbiotic interactions and disease.

Prof. Jonathan Gershenzon Max Planck Institute for Chemical Ecology, Jena, Germany After studying biology at the University of California, Santa Cruz, he received his Ph.D. in Botany from the University of Texas in 1984. He then worked as a scientist at the Institute for Biological Chemistry at the Washington State University. Since 1997 he is a Director and Scientific Member at the Max Planck Institute for Chemical Ecology in Jena, where he heads the Department of Biochemistry. His group studies the biochemistry of secondary plant metabolites, their mode of action on herbivores, the regulation of secondary metabolism in plants, and the evolution of pathways.

Prof. Sarah O’Connor John Innes Centre, Norwich, United Kingdom After her B.S. in Chemistry from the University of Chicago, she went on to obtain her Ph.D. in Organic Chemistry from the Massachusetts Institute of Technology (MIT). In 2000 she began a postdoctoral fellowship in Biochemistry at Harvard Medical School; in 2003 she became Assistant Professor of Chemistry at MIT, a position she held until 2007, when she became Associate Professor of Chemistry at MIT. In 2011 she moved to the United Kingdom to become Project Leader in the Department of Biological Chemistry at The John Innes Centre in Norwich. Her group elucidates and engineers the plant metabolic pathways to harness the wealth of compounds and biocatalysts that the plants have provided.

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Prof. Gordon Brown University of Aberdeen, Aberdeen, Scotland In 1996 he completed his Ph.D. in Microbiology at the University of Cape Town; this was followed by a postdoctoral research fellowship at the University of Stellenbosch. From 1999 to 2003 he was a Wellcome Trust Travelling Fellow at the University of Oxford, and then Wellcome Trust International Senior Research Fellow until 2009 at the University of Cape Town. Since then he has held the 6th Century Chair in Immunology at the University of Aberdeen. His primary research area is innate immunity with emphasis on C-type lectin receptors and their role in antimicrobial immunity and homeostasis. Prof. Oliver Kurzai Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany In 2001 he completed his Staatsexamen (state examination) in human medicine at the University Würzburg, where he earned the title “Dr. med.,” a year later. He spent the next year as a Doctor in practical training (AiP) at the institute for Hygiene and Microbiology at the University Würzburg, where he then became Head of a working group. In 2006 he became a Medical specialist in microbiology, virology, and infection epidemiology at the Bayerische Landesärztekammer (Bavarian State Medical Association). In 2008 he completed his habilitation in medical microbiology at the University Würzburg, and in 2009 he became Professor for Fungal Septomics at the Friedrich-Schiller-University in Jena. Since 2017, he is Professor and Chair of “Medical Microbiology and Mycology” in the University of Würzburg, where he currently studies infection biology of fungi (in particular Candida albicans) and of Neisseria meningitidis. Prof. Christa Schleper University of Vienna, Vienna, Austria Following a Diploma in Biology at the University of Konstanz, she completed her Ph.D. in 1993 at the Max Planck Institute for Biochemistry in Martinsried, where she then also worked as a postdoctoral fellow. In 1996 she moved to the United States for postdoctoral fellowships at the Californian Institute of Technology and then University of California Santa Barbara. She returned to Germany in 1998 to take up an assistant professorship at the University of Darmstadt in the Institute of Microbiology and Genetics. In 2004 she moved to the University of Bergen, Norway, where she was University Professor until 2007. She moved to the University of Vienna to head the Department of Genetics in Ecology, where she currently works as Vice-Head of Department of Ecogenomics and Systems Biology, in particular, leading the group Archaea Biology and Ecogenomics. Her research focuses on the ecology, genetics, and evolution of Archaea, as well as using metagenomics to study natural microbial communities.

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KEYNOTE SPEAKERS Prof. Susan Trumbore Max Planck Institute for Biogeochemistry, Jena, Germany In 1983 she completed both her B.S. and M.A. in Geology at the University of Delaware, followed by an M. Phil. and Ph.D. in Geochemistry at Columbia University. In 1989 she worked as a postdoctoral researcher between the Center for Accelerator Mass Spectrometry, Lawrence Livermore Laboratory in California and the Swiss Federal Institute of Technology in Zurich. Following this, she held the consecutive positions of Assistant Professor, Associate Professor, and Full Professor of Earth System Science at the University of California, Irvine. Since 2009 she has been Director and Scientific Member at the Max Planck Institute for Biogeochemistry in Jena, where she heads the Department of Biogeochemical Processes. Her research explores the key processes and organisms that regulate exchanges of energy, water, and elements between ecosystems and their surroundings. Prof. Manja Marz Friedrich Schiller University, Jena, Germany In 2005 and 2006, she received a Diploma in Biology and a Diploma in Computer science, respectively, from the University of Leipzig. This was followed by her Dr. rer. nat. at the University of Leipzig. In 2010 she became group leader of “RNA Bioinformatics” at PhilippsUniversity Marburg, two years later she became Junior Professor for “High Throughput Sequencing Analysis” at the Friedrich Schiller University, Jena. She held this position until 2015, when she achieved a full Professorship and continues to lead the same group. Her research includes high throughput sequence analysis, comparative genomics, identification and annotation of non-coding RNAs, and other diverse bioinformatics research. Dr. Jaber Dehghany Helmholtz Centre for Infection Research, Braunschweig, Germany He earned his B.Sc. from Zanjan University, Iran, followed by his M.Sc. from the Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran. In 2008 he began his Ph.D. in Systems Immunology at the Frankfurt Institute for Advanced Studies (FIAS). After completing his Ph.D. he took up his postdoctoral researcher position at the Systems Immunology department in the Helmholtz Centre for Infection Research, Braunschweig. His research focuses on the development of agent-based models to represent complex biological systems, in particular insulin granule dynamics in pancreatic beta-cells, and mechanisms of microbial biofilm development.

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Sponsors and media partners

Max Planck Institute for the Science of Human History

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WORKSHOPS

Workshops Monday, March 20th 17:45 - 18:45 Jon Clardy Small molecules and sexual commitment (Room 206) Oliver Kurzai & Marc Thilo Figge Cooperation beyond disciplines - How Systems Biology can really work! (Room 207) Sarah O’Connor How to elucidate biosynthetic pathways in plants (Room 208)

Tuesday, March 21st 17:45 - 18:45 Zoltán Cseresnyés Microscopy imaging; How to produce good images? (Room 206) Sascha Brunke How not to lie with statistics (Room 207) LCMS-8050 – höchst empfindliches und robustes Triple-Quadrupol-MS für die Routineanalytik

Meisterstück Spitzentechnologie, um niedrigste Quantifizierungsgrenzen zu erreichen – das LCMS-8050 erfüllt die wachsende Nachfrage nach selektiven Nachweismethoden im Spurenbereich, etwa für die klinische Forschung, für Umwelt- oder Nahrungsmittelsicherheit. Das LCMS-8050 verbindet eine hohe Sensitivität mit bester Datenqualität und schnellsten Datenaufnahmeraten. • Optimierte Empfindlichkeit im Attogramm-Bereich durch eine beheizte ESI-Quelle und die UFsweeper ®III Kollisionszellentechnologie • Ideale Plattform für ein produktives Labor in Kombination mit der Nexera UHPLC • Einfache Wartung der Ionenquelle (Wechsel von ESI zu APCI) und der Transferkapillare • Komfortable Bedienung durch die nahtlose Integration der HPLC- und MS-Steuerungssoftware LabSolutions LCMS

Susan Trumbore How to get your paper published (or rejected) (Room 208)

Wednesday, March 22nd 14:30 - 15:30 Pierre Stallforth Applying for a Postdoc in the US and Abroad (Room 206) Nicolas König Biologists in Industry - An Insight into Eppendorf (Room 207) María García Altares Mass Spectrometry: Mapping Microbial Interactions (Room 208) Manja Marz MiCom: In Silico (Room 209)

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Poster session Environment E1

The amoeba Protostelium fungivorum feeds on pathogenic yeasts and induces expression of virulence determinants

Silvia Novohradská, Renáta Tóth, Sascha Brunke, Attila Gácser, Gernot Glöckner, Jörg Linde, and Falk Hillmann

p. 46

E2

Mechanisms of survival of Enterococcus mundtii in the intestinal tract of Spodoptera littoralis

Beng Soon Teh, Tilottama Mazumdar, Wilhelm Boland

p. 46

E3

Characterization of drug resistance pattern of bacterial isolates recovered from a bovine abattoir wastewater in Akure, Nigeria

Olubukola Olusola-Makinde, Fatusa Adetuyi, Daniel Arotupin, Anthony Okoh

p. 47

E4

The Merit of Expression Noise Depends on the Environment

Anja Lück, Lukas Klimmasch, Sebastian Germerodt, Christoph Kaleta

p. 47

E5

Targeted gene replacement in two Streptomyces strains

Hanka Brangsch, Erika Kothe

p. 47

E6

Effect of antibiotics in the environment: disturbances of plant-bacterial endophyte interactions in soft rush, Juncus effusus, after repeated exposure to sulfamethoxazole and trimethoprim

Muhammad Arslan, Marcello Santoni, Arndt Wiessner, Thomas Neu, Jochen A. Müller

p. 48

E7

Studying the mechanism of environmental perception in the unicellular green alga Chlamydomonas reinhardtii

Prasad Aiyar, Daniel Schaeme, Hannes Dathe, Severin Sasso and Maria Mittag

p. 48

E8

Investigation of microbial community in extreme saline environments

Madlen Franze, Andrea Cherkouk

p. 48

E9

The role of oxidative stress in the antifungal drug response of A. fumigatus

Elena Shekhova, Olaf Kniemeyer, Axel A. Brakhage

p. 49

E10 Response of ectomycorrhizal partners to metal stress

Manuela Östreicher, Katrin Krause, Erika Kothe

p. 49

E11 Establishing a model system for studying interactions of flagellate green microalgae in the marine environment

David Carrasco, Severin Sasso, Maria Mittag

p. 49

E12 Influence of soil-bacteria on the phytoremediation-potential of different tree species on the testing-site Gessenwiese

David Fürst, Sebastian Pietschmann, Daniel Mirgorodsky, Dirk Merten, Georg Büchel, Erika Kothe

p. 50

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POSTER SESSION

E13 Ectomycorrhizal fungi reduce metal toxicity of birch trees growing on a former uranium mining site as revealed by micro-PIXE analysis

Arno Märten, Steffi Formann, Mitja Kelemen, Primož Vavpetiˇc, Primož Pelicon, Katarina Vogel-Mikuš

p. 50

E14 Heavy metal tolerance mechanisms in Streptomyces

Thomas Krauße, Benjamin Funai, Karin Martin, Florian Kloß, Nico Jehmlich, Boyke Bunk, Jörg Overmann, Erika Kothe

p. 51

E15 Identification of microorganisms mobilizing radionuclides from black slate

Marie Harpke, Katja Burow, Erika Kothe, Georg Büchel

p. 51

Pathogenesis P1

An Audit of Dengue Fever Cases in the Year 2013 at Civil Hospital Karachi-Pakistan

Asma Bashir

p. 51

P2

The effect of Candidalysin on bacteria

Toni Förster, Selene Mogavero, Bernhard Hube

p. 52

P3

The peroxiredoxin Asp f3 protects A. fumigatus against external superoxide

Jana Boysen, Bettina Bardl, Falk Hillmann

p. 52

P4

A taxonomic revision of the mucormycosis causing Mucor circinelloides complex

Lysett Wagner, Volker Schwartze, Kerstin Voigt, Sybren de Hoog, Oliver Kurzai, Grit Walther

p. 53

P5

Proteomic studies on the degradation of DHN melanin, a fungal virulence factor

Annica Pschibul, Thomas Krüger, Olaf Kniemeyer, Axel A. Brakhage

p. 53

P6

Regulatory mechanisms of staphylococcal persistence

Anke Siegmund, Fabio Gratani, Christiane Wolz, Silke Niemann, Bettina Löffler, Lorena Tuchscherr

p. 54

P7

Staphylococcus aureus pathogenesis: from sepsis to hematogenous chronic bone infections.

Christine Pöllath, Bettina Löffler, Lorena Tuchscherr

p. 55

P8

How do phytoplasmas generate ‘zombie plants’? Interaction of the bacterial effector protein SAP54 with floral homeotic proteins

Marc-Benjamin Aurin,Florian Rümpler, Matthias Görlach, Günter Theißen

p. 55

P9

Investigation of protein interactions to elucidate the function of unknown proteins of the human pathogenic fungus Aspergillus fumigatus

Marcel Noßmann, Falk Hillmann, Axel Brakhage, Thomas Munder

p. 55

Sophia Ruben, Ronny Martin, and Oliver Kurzai

p. 56

P10 The role of the transcription factor Ahr1 in ECE1 expression in Candida albicans

17

P11 Evaluation of Electrochemiluminescence and enzyme-linked immunosorbent assays for diagnosis of toxoplasma infections in pregnant women

Blerta Laze, Aarta Lugaj

p. 57

P12 The human pathogenic fungus Aspergillus fumigatus counteracts phagolysosomal function by interference with flotillin-dependent lipid rafts through conidial melanin

Franziska Schmidt, Marie Röcker, Hella Schmidt, Andreas Thywissen, Martin Westermann, Thorsten Heinekamp, Scott G. Filler, Axel A. Brakhage

p. 57

P13 Candida albicans genes associated with translocation through intestinal epithelial barriers

Stefanie Allert, Toni Förster, Marc Juraschitz, Daniela Schulz, Betty Hebecker, Tony Pawlik, Ilse D. Jacobsen, Lydia Kasper, Bernhard Hube

p. 57

P14 Characterization of the Candida albicans ECE1 promoter

Enrico Garbe, Ronny Martin, Slavena Vylkova and Oliver Kurzai

p. 58

P15 Characterizing innate immune cell activation by fungal pathogens using Live cell imaging

Alessandra Marolda, Kerstin Hünniger, Naim Al-Zaben, Marc Thilo Figge, Oliver Kurzai

p. 58

P16 Iron regulation in the pathogenic fungus Aspergillus fumigatus: Functional domain analysis of the central regulator HapX

Mareike Scheven, Matthias Misslinger, Peter Hortschansky, Hubertus Haas, Axel A. Brakhage

p. 59

P17 Actinobacteria – a source for antivirulence leads?

Nico Ortlieb, Elisa Liebhart, Timo H. J. Niedermeyer

p. 59

P18 Characterization of Aspergillus fumigatus mutants regarding their interactions with human leukocytes

Mai Hoang, Martin Föge, Susann Hartung, Juliane Macheleidt, Axel A. Brakhage, Marie von Lilienfeld-Toal

p. 60

P19 Analysis and differentiation of the small colony variant phenotype of Staphylococcus aureus in comparison to the wildtype using Raman spectroscopy

Frederike Gladigau, Christina Ebert, Lorena Tuchscherr, Bettina Löffler, Jürgen Popp, Ute Neugebauer

p. 60

P20 Effect of different resin composite monomers (methacrylate and silorane) on two cariogenic bacteria / In vitro study

Marwa Mohamed Elsheikh, Ahmed Ali Musrati, Ahmed Safwat Elkady

p. 61

P21 Serosurvey of Crimean-Congo Hemorrhagic Fever Virus Among Sheep and Goats in Lezhe District of Albania

Arta Lugaj, Blerta Laze, Isolde Schuster, Marc Mertens, Martin Groschup, Kristaq Berxholi

p. 61

P22 Antimalarial potential of Liposomal Zinc pyrithione

Mohsin Raza, Prahlad C Ghosh

p. 62

P23 Iron redistribution after Candida albicans infection in the murine kidney

Agata Kilar, Theresia Conrad, Jorg Linde, Joanna Polanska ´

p. 62

18

POSTER SESSION

P24 Factor H-related protein 1 (FHR1) binds to C. albicans and acts pro-inflammatory in monocytes

Sarah Irmscher, Susana Hidalgo Vico, Stefan Lorkowski, Christine Skerka

p. 63

P25 Studying the role of CgMIP1 in the evolution of Candida glabrata during adaption to the human host

Sofía Siscar-Lewin, Sascha Brunke, Bernhard Hube

p. 63

Chemical ecology C1

Genomic and metabolomic analysis of Termitomyces sp., the fungal mutualist of Macrotermitinae

Nina Kreuzenbeck, Victoria Challinor, Haofu Hu, Saria Otani, Michael Poulsen, Christine Beemelmanns

p. 63

C2

Bacterial-algal interactions mediated by siderophores

Colette Kurth, Markus Nett

p. 64

C3

Bacterial Natural Products Involved in Soft Rot of White Button Mushrooms

Tawatchai Thongkongkaew, Evgeni Bratovanov, María García-Altares, Kirstin Scherlach, Christian Hertweck

p. 64

C4

Identification and characterization of an Arabidopsis mutant impaired in calcium signaling

Johannes Thürich, Lothar Altschmied, Elena Petutschnig, Ralf Oelmüller

p. 65

C5

Interactions between Chlamydomonas reinhardtii and other microorganisms

Daniel Schaeme, Prasad Aiyar, Maria Mittag, Severin Sasso

p. 65

C6

Effect of bacteria on growth and mating of the benthic diatom Seminavis robusta: a metabolomic approach

Emilio Cirri, Georg Pohnert

p. 65

C7

Triacylglycerols and polar lipids fuel the wound activated oxylipin production of the moss Dicranum scoparium

Daniel Stettin, Verena Jeschke, Georg Pohnert

p. 66

C8

The role of bacterial volatiles in the long-distance microbial interspecific interactions

Adam Ossowicki, Sylwia Jafra, Paolina Garbeva

p. 66

C9

Survey of allelopathic interactions in phytoplankton

Lydia A. Papanikolopoulou, Franziska Speck, Colomban de Vargas, Ian Probert, Georg Pohnert

p. 66

C10 Chemical communication between iron oxidizing and iron reducing bacteria in iron snow

Qianqian Li, Jiro F. Mori, Carl-Eric Wegner, Rebecca E. Cooper, Kirsten Küsel

p. 67

C11 Interactions of Rhizobacteria in Legume-Cereal Intercropping System

Siddhi Vora, Mugdha Kulkarni, Gattupalli Archana

p. 67

C12 What triggers transcriptional regulation of organohalide respiration in Sulfurospirillum ssp.?

Jens Esken, Tobias Goris, Torsten Schubert, Gabriele Diekert

p. 67

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C13 Hunting strategies of the soil amoeba Protostelium mycophaga on the fungal pathogen Aspergillus fumigatus

Iuliia Viediernikova, Falk Hillmann

p. 68

Natural products N1

Superbug of nosocomial infection methicillin-resistant Staphylococcus aureus (MRSA) and recent trends in antibiotic susceptibility pattern

Kiran Fatima

p. 68

N2

Discovery of eukaryotic cryptic natural products by heterologous expression

Jun Lin, Maria Stroe, Sandra Hoefgen, Derek J. Mattern, Huijuan Guo, Axel A. Brakhage, Christine Beemelmanns, Vito Valiante

p. 69

N3

Streptomyces iranensis genetic manipulation paves the way for identification of the eliciting agent of gene cluster activation in Aspergillus nidulans

Mario Karl Claude Krespach, Tina Netzker, Volker Schroeckh, Kirstin Scherlach, Christian Hertweck, Axel A. Brakhage

p. 69

N4

A Bioactive Compound Effective Against Candida albicans from Syncephalastrum Species

Alemayehu Amare, Dawit Abate

p. 69

N5

Discovery of new antifungal compounds from the social amoeba Dictyostelium discoideum

Tom Lauterbach, Silvia Novohradská, Matthias Steinacker, Falk Hillmann

p. 70

N6

Pattern recognition methods for prediction of chemical structures of fungal secondary metabolites

Sagar Gore, Ekaterina Shelest

p. 70

N7

Actinomycetes and yeasts from a heavy metal contaminated site

Benjamin Funai, Karin Martin, Katrin Krause, Martin Roth, Erika Kothe

p. 71

N8

Morphological evaluation and antimicrobial activity of terrestrial cyanobacterial strains from agricultural lands of Kermanshah province, Iran

Sara Abbasi, Javad Hamedi, Bahareh Nowruzi

p. 71

N9

Adaptation of the filamentous fungus Aspergillus nidulans to low temperature stress

Benjamin Hanf, Thomas Krüger, Boyke Bunk, Derek Mattern, Jörg Overmann, Olaf Kniemeyer, Axel A. Brakhage

p. 72

N10 Silent gene cluster characterisation in Aspergillus fumigatus

Maria C. Stroe, Tina Netzker, Vito Valiante, Axel A. Brakhage

p. 72

N11 Cyanobacterial metabolites with inter-species communication functions

Tomasz Chilczuk, Timo Niedermeyer

p. 72

N12 Development of droplet microfluidic platform with integrated optical fibers for microbial screening

Sundar Hengoju, Miguel Tovar, Thomas Weber, Lisa Mahler, Mahipal Choudhary, Oksana Shvydkiv, Martin Roth

p. 73

20

POSTER SESSION

Systems biology S1

Detection of Mutations in the gyrA Gene of Salmonella enterica Serovar Typhi

Mahsa Roshandel, Shadi Ghalami

p. 73

S2

Evaluation of Antibacterial activities and Molecular docking studies of Di-peptide

Shylesh Murthy, Mousami Das, Vivek Chandramohan, Makari Hanumanthappa, Hithesh Kumar

p. 74

S3

Dimensionality of motion and binding valency govern receptor-ligand kinetics as revealed by agent-based modelling

Teresa Lehnert, Marc Thilo Figge

p. 74

S4

Dynamic optimization of pathway regulation and cytoxicity prediction of metabolites in pathogenic fungi exploit the hidden potential of toxic metabolites as drug targets

Jan Ewald, Martin Kötzing, Martin Bartl, Thomas Dandekar, Humberto González-Díaz and Christoph Kaleta

p. 75

S5

Migration and interaction tracking for quantitative analysis of phagocyte-pathogen confrontation assays

Susanne Brandes, Stefanie Dietrich, Kerstin Hünniger, Oliver Kurzai, Marc Thilo Figge

p. 75

S6

Modeling the metabolic reprogramming of macrophage activation

Franziska Hoerhold, Marcus Oswald, Rainer König

p. 76

S7

Raman spectroscopic investigation of human neutrophil interactions with sepsis-associated pathogens

Angelina Pittner, Natalie Töpfer, Marcel Dahms, Anuradha Ramoji, Oliver Kurzai, Jürgen Popp, Ute Neugebauer

p. 77

S8

Effect of organic products on the improvement of soil microbiological functioning under saline conditions of arid regions: Impact on carbon and nitrogen mineralization

Mabrouka Oustani, Mohammed Tahar Halilat, Haroune Chenchouni

p. 77

S9

In silico experiments of fungal and bacterial infections in virtual neutropenic patients suggest optimal treatment strategies

Sandra Timme, Maria Prauße, Teresa Lehnert, Kerstin Hünniger, Oliver Kurzai, Marc Thilo Figge

p. 78

S10 Iron redistribution after Candida albicans infection in the murine kidney

Theresia Conrad, Agatha. Kilar, Reinhard Guthke, Jörg Linde

p. 78

S11 Enhanced Detection of Unstained Cells in an Existing Segmentation and Tracking Framework

Naim Al-Zaben, Anna Medyukhina, Alessandra Marolda, Kerstin Hünniger, Oliver Kurzai, Marc Thilo Figge]

p. 79

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Non-scientific programme Welcome reception Venue: Haus auf der Mauer On the first day an informal evening session is planned for socializing with fellow conference attendees as well as the keynote speakers. The Haus auf der Mauer, situated in the remains of Jena’s city wall from the 15th century, will provide a relaxed and inquisitive atmosphere along with some food and drinks to keep up the energy.

Conference dinner Venue: Restaurant Landgrafen One of the highlights of our four-day scientific journey is the Conference Dinner. This year’s dinner will be hosted at the Landgrafen restaurant, with panoramic views over the city of Jena. The dinner promises some entertainment, ample time to interact with speakers, participants, some local researchers, all with a buffet of regional and international cuisine to complement it.

22

NON-SCIENTIFIC PROGRAMME

Social activities Jena is a multifaceted city with high historical and scientific background. On Wednesday afternoon you will have the chance to explore our city by visiting the planetarium, having a city tour or going for a hike in Jena’s beautiful surrounding.

Planetarium Are you interested in stars, planets and the origin of life? Then visit the Zeiss-Planetarium, the world’s oldest continuously working planetarium. Have a look at the projection technique by watching a scientific program “Cosmic evolution”.

Hiking tour The science city Jena is surrounded by a pleasant mountainous landscape in a very short distance from the city center. Get a nice overview of the city from a mountain near the conference venue. Let’s head out into nature together!

Guided city tour During a sight-seeing tour expert guides will show you the most interesting spots and treasures in the richly historical and rapidly changing city of Jena. Learn about key moments in the history of Jena and the Friedrich-Schiller-University.

Science slam You love to drink beer during listening to interesting understandable talks? Young scientists will present their research within a few minutes in a popular scientific way. Everything is allowed how to present. The public will decide who will win this entertaining competition. Beside of this you have the opportunity to communicate with other young scientists in a pub-like environment.

Pub crawl Germany is indeed well known for the beer produced here. So we propose- ‘When in Germany, drink like a German’! Luckily Jena understands the alcoholic needs of students and is well prepared to host you in this aspect. Join fellow MiCom participants for a tour of Jena’s best bars and pubs to ‘Prost’ your way to a memorable night.

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Talk abstracts Keynotes Chemical ecology session I - Prof. Jon Clardy Lessons from the microbial metabolites that regulate multilateral symbioses Jon Clardy Harvard Medical School, Boston, United States

Fungus-growing insect systems in which insects collect plant (and other) material to feed their fungal crop have evolved at least three times: bark beetles, termites, and ants. These systems also involve microbial symbionts including a specialized fungal pathogen and bacteria that provide chemical defenses, and small molecules regulate the complex set of interactions between insects, fungi, and bacteria. The lecture will largely focus on ant studies, but the termite and beetle systems will be mentioned. There are many motivations for studying the fungus-growing ant system – discovering new molecules and their biosynthetic pathways, decoding the evolutionary strategies of biosynthetic diversification, revealing cryptic metabolites, and potentially providing therapeutic agents. The lecture will give examples to illustrate each of these points.

Natural products I - Prof. Sarah O’Connor Harnessing the chemistry of plant natural product biosynthesis Sarah E. O’Connor John Innes Centre, Norwich, United Kingdom

Plants, which make thousands of complex natural products, are outstanding chemists. Through the concerted action of enzymes that are assembled into metabolic pathways, nature creates chemical complexity from simple starting materials. This lecture will highlight some of the unusual enzymatic transformations that plants use to make complex, bioactive natural products. We will also discuss methods by which these pathways can be harnessed for metabolic engineering. We will focus on the biosynthesis of the monoterpenes called iridoids, and the alkaloid derived from iridoids, known as the monoterpene indole alkaloids. Here we will describe the discovery, functional characterization and mechanistic study of several enzymes involved in the biosynthesis of these important compounds in several medicinal plant species.

Pathogenesis session I - Prof. Oliver Kurzai Host – Pathogen Interplay in Invasive Fungal Infection Oliver Kurzai Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany

Fungal pathogens pose a considerable threat for immunocompromised patients. Invasive fungal infections are difficult to detect and despite treatment result in a poor prognosis. Innate immunity is essential for defense against most fungal pathogens. In the case of Aspergillus fumigatus, neutropenia or functional impairment of neutrophils a major clinical risk factors for invasive infection. In contrast, most patients suffering from systemic Candida infection are not neutropenic. However, it is well known that neutropenia increases the risk for disseminated infection and decreases the likelihood of favorable outcome in systemic Candida infection. In our work, we analyse the response of primary human immune cells to fungal pathogens. Data from a human whole blood infection model show how infection with Candida albicans results in activation of innate immune responses and elimination of extracellular Candida albicans. Biomathematical modeling allows

24

KEYNOTE TALKS quantitative predictions of phagocytosis rates for defined host cell types and clearly underlines, that neutrophils are central for elimination of the fungal pathogen. Activation of neutrophils occurs in two steps with the first depending on rapid complement activation and generation of anaphylatoxin C5a and the second depending on phagocytosis, which occurs mainly via complement receptor 3 (CR3). Importantly, innate immunity is not stereotypically responding to “fungi” but can discriminate between different fungal pathogens like Candida albicans and Candida glabrata. In addition, genetic polymorphisms modulate the interaction between host and pathogen during systemic infection. Thus, both pathogen and host variability need to be taken into account when trying to understand infection biology and this understanding is taken up in personalized or precision medicine concepts.

Chemical ecology session II - Prof. Jonathan Gershenzon Microbially mediated associations between conifers and conifer insects Dinesh Kandasamy, Aileen Berasategui, Axel Schmidt, Martin Kaltenpoth, Almuth Hammerbacher, Jonathan Gershenzon Max Planck Institute for Chemical Ecology, Jena, Germany

Insects that feed primarily on conifer trees are often reported to have microbial associates. These are thought to help insects overcome the low nutrient content of a typical conifer diet and the high levels of structural and chemical defenses. However, the specific roles of most microbes living in association with conifer insects are completely unknown. We have been studying two beetles that attack Norway spruce trees in central and northern Europe. One, the pine weevil, contains gut bacteria that were found to degrade major defense compounds of the host tree. An association of Wolbachia, Enterobacteria and Firmicutes was shown to metabolize the resin acids ingested into pine weevil guts. Although the weevil itself has higher fitness with its bacteria than without, the insect curiously does not appear to benefit directly from bacterial diterpene degradation. The second insect, the spruce bark beetle, associates externally with several species of ophiostomatoid fungi, one of which, Endoconidiophora polonica, can kill a tree by itself if injected in sufficient numbers. This fungus was shown to readily metabolize the major phenolic defenses of its spruce host. The strong dependence of the insect on the fungus is demonstrated by the way beetle larvae feed almost exclusively behind the fungal invasion front, and the way adult beetles use volatile cues to locate the fungal mycelium. However, the contribution of the fungus to beetle success is still under investigation. The possible functions of microbes in enhancing conifer insect performance will be evaluated.

Environment session I - Prof. Christa Schleper Ecology, Physiology and Evolution of Ammonia oxidizing Archaea Christa Schleper Archaea Biology and Ecogenomics Division, Center of Ecology, University of Vienna, Austria

Since their discovery about 12 years ago, ammonia oxidizing archaea (AOA) have been recognized as one of the most abundant microbial groups in aquatic and terrestrial environments. About a dozen cultivated strains and numerous (meta-) genomic studies have provided evidence that carbon and energy metabolisms of AOA evolved independently from their bacterial counterparts, resulting in fundamentally different phenotypes and differences with respect to greenhouse gas emissions. I will discuss recent physiological and proteogenomic studies as well as evolutionary aspects of AOA, since it remains a mystery why and how particularly this group of archaea has managed to radiate into aerobic moderate environments where it competes successfully with bacteria.

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Systems biology session I - Prof. Manja Marz Fight Infections in silico Manja Marz RNA Bioinformatics/High Throughput Analysis, Friedrich Schiller University of Jena, Germany

We will explore the computational analysis of infection samples after transcriptome sequencing. While mRNA analysis starts to get standardized, the analysis of non coding RNAs is usually specific. Non-coding RNAs (ncRNAs) as transcription factors or cis-acting antisense RNAs are known to be involved in gene regulation. However, the processes during infections especially in terms of therapeutic impact are unknown. We will analyze E. coli, A. fumigatus, C. albicans and Ebola infection. Compared to protein-coding genes, fungi and bacteria induce an expression change in relatively few ncRNAs, but with massive fold changes. We observe variation in the isoforms composition for several lncRNA following infection. We will explore ncRNAs as excellent marker genes for infectious diseases.

Environment session II - Prof. Susan Trumbore Using C isotopes to scale from microbes to landscapes Susan Trumbore [1], Martin Nowak [1], Valerie Schwab [2], Kai Uwe Totsche [2], Kirsten Küsel [2] [1] Max-Planck Institute for Biogeochemistry, Jena, Germany [2] Friedrich Schiller University of Jena, Germany

A grand challenge in biogeochemistry is to link the large amounts of information on microbial community and function to processes and fluxes in biogeochemical cycles that emerge at larger spatial scales. One way to link processes across scales is to use isotopic tools to trace sources and quantify rates. In the Collaborative Research Center AquaDiva, groundwaters with very different hydrochemical properties and microbial communities have been identified in carbonate aquifers in a hillslope transect near the Hainich National Park in central Germany. We use carbon stable isotopes and radiocarbon to link activities found in microbial communities in these habitats to the overall sources and cycling of carbon in the different groundwaters. Among the results are the tracing of fossil C sources into the microbial community and evidence of recycling of C through CO2 fixation.

Pathogenesis session II - Prof. Gordon Brown C-type lectins in Immunity Gordon Brown The University of Aberdeen, Aberdeen, United Kingdom

The last few decades has seen a tremendous increase in our understanding of the mechanisms underlying the development of protective anti-microbial immunity. Key among these discoveries is the identification of pattern recognition receptors (or PRRs) expressed by immune cells which recognise conserved microbial components, such as beta-glucans. Recognition of these structures by PRRs, particularly by members of the C-type lectin receptor (CLR) family, triggers intracellular signalling cascades that initiate a variety of cellular and inflammatory responses, and induce the development of pathogen specific adaptive immunity. We now understand that innate recognition by CLRs is essential for the development of protective antimicrobial immunity but there is also emerging evidence that the functions of these receptors play a role in homeostasis and autoimmunity. In this presentation, I will cover the recent developments in our understanding of the function and roles of these receptors.

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TALKS - ENVIRONMENT Systems biology session II - Dr. Jaber Dehghany Early markers determine the formation of mushroom-like biofilms by Pseudomonas aeruginosa Jaber Dehghany Research Group Systems Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany

P. aeruginosa biofilms form mushroom-shaped structures under certain circumstances. Bacterial motility and the environment affect the eventual mushroom morphology, but we have yet to understand their role in driving this particular morphology. While experiments shows that migration of cells play a key role in this process, it is not clear why motile cells migrate on top of the previously established microcolonies. For this purpose we have developed an agent-based model for the bacterial dynamics and interactions influencing bacterial biofilm shape. Cell motility in the model, which happens on the surface of substratum as well as microcolonies, relies on recently published experimental data. While motile cells escape from a single colony by nutrient chemotaxis, they migrate onto the top of the colonies at higher number density of non-motile colonies and form mushroom-shaped structures. This model proposes that the formation of mushroomshaped structures can be predicted by parameters at the time of bacteria inoculation. Depending on nutrient levels and the initial number density of stalks, mushroom-shaped structures only form in a restricted regime. This opens the possibility of early manipulation of spatial pattern formation in bacterial colonies, using environmental factors.

Environment session Be small and find a host – do oligotrophic subsurface environments support symbiotic and parasitic relationships among microorganisms? Martina Herrmann [1,2], Patricia Lange [1], Martin Taubert [1], Lena Carstens [1], Carl-Eric Wegner [1], Cassandre Sara Lazar [1], Kai Uwe Totsche [3], Kirsten Küsel [1,2] [1] Friedrich Schiller University Jena, Institute of Ecology, Aquatic Geomicrobiology, Jena, Germany [2] German Center for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany [3] Friedrich Schiller University Jena, Institute of Geosciences, Hydrogeology, Jena, Germany

Traditional research of subsurface microbiology has mostly focused on interactions between microorganisms and predatory protists or consequences of viral attack on microbial populations. In contrast, symbiotic or parasitic interactions have so far received less attention due to the pore size dependent absence of larger host organisms in subsurface environments. Studies of groundwater environments recently reported the occurrence of ultra small bacteria belonging to Candidate phyla for which parasitic or symbiotic life styles were predicted as a consequence of genome size reduction and loss of metabolic functions. Within the framework of the CRC AquaDiva, we analyzed samples from two superimposed limestone aquifer assemblages to (i) assess the fraction of ultra-small bacteria in the groundwater populations and (ii) infer potential (symbiotic or parasitic) interactions within microbial networks based on co-occurrence patterns of microbial taxa across filter size fractions. Groundwater samples were processed by filtration through 0.2 μm and subsequently through 0.1 μm filters. Quantitative PCR and MiSeq Illumina amplicon sequencing indicated that 0.6-54% of the total bacterial population was passing through the 0.2 μm filter and that the 0.1 μm filter fraction harbored a high fraction of members of Candidate phylum OD1 including potential symbionts or parasites. Our findings suggest that microbes smaller than 0.2 μm may constitute a considerable fraction of the groundwater microbial community, representing yet poorly characterized microbial diversity with unknown metabolic capacities. Ongoing work on co-occurrence of microbial groups aims at the identification of potential partners of symbiotic relationships or likely combinations of hosts and parasites among bacteria or between bacteria and eukaryotic microorganisms.

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The dominating bacteria in the gut of Spodoptera littoralis Tilottama Mazumdar, Beng Soon Teh, Wilhelm Boland Max Planck Institute for Chemical Ecology, Department of Bioorganic Chemistry

Insects harbour a plethora of microorganisms within their gut as their normal flora. They are not only non-pathogenic to them, but also have roles to play in the insect growth, development and immunity. There lies a complex interaction within the microflora and, between the host and the microorganisms. This leads to variations in the microbial population with the development of the insect. The gut microbiota of Spodoptera littoralis, a Lepidopteran insect, has been elucidated. The core community consists of Enterococci, Lactobacilli and Clostridia. The variation and selection of one bacterial species over the other is quite evident throughout the life-cycle. By the time the larva reaches the 5th instar stage, Enterococcus mundtii and Clostridia sp. persist and dominate. Also, there is a difference in the presence and abundance of bacteria among the fore, mid and hind gut of the larva. The gut environment is adverse. There is a pH gradient from alkaline to neutral along fore to hind gut respectively. Also, there is a depleted iron condition as posed by the chelator 8-hydroxyquinolin-2-carboxylic acid produced by the insects. A GFP-tagged reporter E. mundtii has been constructed to show that it is the persistent species in the gut. This reporter bacteria will be used to answer these questions: Factors bringing about their dominance, their mechanisms of surviving the gut stress, the kind of interaction going on between them and their host. Thus, they are fed to the insects at early instars, and sorted from the gut spatially and temporally, using flow-cytometry. Next generation RNA sequencing of the sorted bacteria has given us preliminary answers to our questions. There are upregulated pathways for stress survival: quorum sensing, biofilm formation, two-component systems, resistance towards oxidative stress. There is a differential regulation among various metabolic pathways too. Further investigation is required to validate the pilot study. Microbial monitoring in an underground environment – aspects from Romanian show caves Silviu Bercea [1], Ruxandra Nastase-Bucur [1], Dragos, M˘antoiu [2], Ionut, Mirea [2], Alexandru Petculescu [2], R˘azvan Arghir [2], Marius Kenesz [1], Silviu Constantin [2], Oana Teodora Moldovan [1] [1] Department of Cluj, Emil Racovi¸ta˘ Institute of Speleology, Cluj-Napoca, Romania [2] Department of Geospeology and Palentology, Emil Racovitza Institute of Speleology, Bucuresti, Romania

Microbiological monitoring is a robust tool and a valuable indicator used in environmental monitoring. The study involved five Romanian show caves: Urs, ilor, Muierilor, Meziad, Polovragi and Fundata, located in different parts of the Carpathian Mountains. Microbiological monitoring test kits (RIDA@Count, R-Biopharm AG, Germany) were used for the observation of the relative abundance in show caves of aerobic bacteria, yeasts and molds, and clinically important, human-associated groups as Enterobacteriaceae and Coliform bacteria, with specific indicators for Escherichia coli . For 16S rRNA gene sequencing, agar based cultures were prepared and cultured ex situ. The extensive microbial monitoring was done between March 2015 and March 2016, and revealed that the overall number of colony-forming units (CFU) was lower in the winter months, although almost a permanent presence of microbes was found in the sampling sites, while the CFU varied in all of the studied caves, with very few absences of CFU in the overall studied sites. Fungi colonies were almost constantly present, although in lower numbers than bacteria. Human human-associated groups were found to be present in the visited parts of the cave systems, representing a potential health hazard. The position of the sampled areas and the varying seasonal peaks in the sampling points, might suggest that most of the bacterial loads are being determined by a variety of factors. The rise of culturable microorganisms observed in areas of the caves that were subject to intense human visitation, in contrast to unvisited parts of the systems, on the other hand, gives a good indication of the dominant anthropogenic factors.

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TALKS - ENVIRONMENT

Love and Hate in the Subsurface - Growth Promotion and Inhibition induced by Groundwater Bacteria Patricia Geesink [1,2], Olaf Tyc [2], Kirsten Küsel [1,3], Paolina Garbeva [2] [1] Aquatic Geomicrobiology, Institute of Ecology, Friedrich Schiller University Jena, Germany [2] Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO BOX 50, 6700 AB Wageningen, Netherlands [3] German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany

The production of antimicrobial substances by bacteria to increase their competitiveness against other bacteria is a known phenomenon in soil ecosystems which harbor a broad diversity of bacteria. Antimicrobial substances are useful weapons against competitors for the often limited nutrients resources in these ecosystems. Aquifers, an even more nutrient limited ecosystem, have so far never been studied regarding their potential of antimicrobial compounds production. In this study we developed a high-throughput screening method that allowed a quick evaluation of both, growth inhibiting and growth promoting effects, using an AlamarBlue based assay. With this technique, we were able to screen 192 bacterial isolates derived from two superimposed aquifer assemblages in the Hainich area (Germany) and the effect of secondary metabolites excreted by them in monocultures as well as in more than 1000 random one-to-one interactions. Our results revealed that 23% of all tested interactions induced growth inhibition of at least one of the two model organisms S. aureus 533R4 or E. coli WA321 whereas only 4% of the interactions induced growth promotion. Looking at one-to-one interactions on phylum level we could show that especially γ-Proteobacteria are inducing growth inhibition on both model organisms whereas growth promotion on S. aureus is strongest induced by α-Proteobacteria-Firmicutes interactions. Growth of E. coli on the other hand was mostly favored in interactions of Firmicutes with Actinobacteria, α- or β-Proteobacteria. Here we show for the first time the production of growth inhibiting secondary metabolites by groundwater bacteria. With the established high-throughput screening method we will be able to further elaborate and understand the complex interspecific network in bacterial aquifer communities. Are subsurface fungal communities reflection of surface fungal communities? Ali Nawaz, François Buscot, Tesfaye Wubet Department of Soil Ecology, Helmholtz Centre for Environmental Research - UFZ, Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

Subsurface groundwater aquifers are primarily recharged by the infiltration of surface water, which brings down not only the dissolved organic matter but also the surface microbial communities into the subsurface. Aboveground surface conditions like vegetation cover and landuse management types have profound impact on the belowground fungal community structures and compositions. Whereas the effects of these surface conditions on the subsurface fungal communities beyond the rooting zone in fresh water aquifers at different depths are largely unknown. We hypothesized that the fungal communities in the subsurface groundwater aquifers largely reflect the surface fungal communities of the specific recharge areas. To test this hypothesis, surface (soil sampling plots in the recharge areas) and subsurface (two superimposed limestone aquifers at different depths, ranging from 8.5 to 84 m depth from the surface) samples were collected from Hainich Critical Zone Exploratory. Fungal internal transcribed spacer (ITS) rDNA gene was sequenced by using DNA based high-throughput sequencing to study the differences in the community structures and compositions in two different but connected (with the special geological structures) habitats. Our results indicated that the fungal OTUs belonging to phylum Basidiomycota and Ascomycota dominate the aquifers. The core fungal microbiome of surface and subsurface samples indicates the high similarities between two habitats reflecting that surface conditions

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have impact on the subsurface fungal communities. Specifically the presence of different functional groups and, in particular plant and cattle pathogens that are not typical of subsurface habitats, further strengthened our hypothesis. In addition to this, we also find fungal taxa specific to the subsurface samples only and that points to a groundwater specific fungal microbiome also. Phytoremediation: soil microbes and their activity Sebastian Pietschmann [1], David Fürst [1], Daniel Mirgorodsky [2], Dirk Merten [2], Georg Büchel [2], Erika Kothe [1] [1] Institute of Microbiology, Friedrich Schiller University, Jena, Germany [2] Institute of Geosciences, Friedrich Schiller University, Jena, Germany

Contamination as a result of excessive mining activity or decommission of gas, coal or nuclear power plants affects vast areas worldwide. Most of the currently used remediation approaches are highly expensive, laborious and inadvertently destructive to the native microbial community. Here, the use of microbially enhanced phytoremediation as an in situ technique with minimal invasiveness is used to evaluate the potential for soil remediation in consequence of former uranium mining activity. In eastern Thuringia, test field sites were set up to grow herbaceous and woody plants in short rotation coppice, the biomass of which can be used for bioenergy production through fermentation or combustion. The potential land-use of metal contaminated sites is one of the major advantages of this approach. The four testing fields were amended with rendzina soil (at 5 or 20%) to neutralize the acidic conditions of the contaminated substrate. For erosion control and phytoextraction, red fescue (Festuca rubra) and millet (Sorghum bicolor) or rye (Secale multicaule) were planted between the rows of trees used for phytostabilization (Betula pendula, Salix triandra x viminalis „Inger", Alnus incana, Sorbus aucuparia, Pinus sylvestris). Furthermore, to enhance the remediation efficiency, growth and stress tolerance of the plants, the substrate was modified by different inocula consisting of metal resisting bacteria and mycorrhizal fungi. Microbial cell numbers and soil respiration were monitored since 2015. The bacterial community was analyzed by 16S amplicon sequencing showing predominant genera. The effects of inoculation and soil amendments are visible with changes in soil respiration, pH and microbiome analyzes. Microbially-induced release of elements/radionuclides Katja Burow [1,2], Anja Grawunder [1], Marie Harpke [2], Daniel Schäfer [2], Stephan Bock [1], Norman Dietrich [3], Dirk Merten [1], Erika Kothe [2], Georg Büchel [1] [1] Institute of Geosciences, Applied Geology, Friedrich Schiller University Jena, Germany [2] Institute of Microbiology, Microbial Communication, Friedrich Schiller University Jena, Germany [3] Strahlenschutz, Analytik und Entsorgung Rossendorf e.V. (VKTA), Dresden, Germany

The potential release of radionuclides from rock into soils and groundwater is a long-time endangerment to the environment. The (im)mobilization of elements is not strictly an abiotic process; in fact microorganisms contribute to metal release, transport and (co)precipitation. Therefore, the effect of microorganisms on release and transport of elements/radionuclides from rock into groundwater was investigated. Samples of black slate as well as precipitates and seepage water of the former alum mine ’Morassina’ were characterized (hydro)geochemically and mineralogically. The seepage water is acidic (pH 2.6-3.7) and contains high concentrations of iron and sulfate, originating from pyrite oxidation within the low grade metamorphic silurian slate, which contains U, Th and Ra. The Fe-precipitates were characterized as schwertmannite, jarosite and the Fe-phosphate diadochite. Microbes from secondary Fe-precipitates and drip water were isolated to access the active community and the microbial community was in addition analyzed by nextgeneration sequencing. The community consisted primarily of Fe-oxidizers like Leptospirillum sp. in the bacterial, and chytrids like Rhizophydium sp. in the fungal domain. Cultivation showed high fungal prevalence with e.g. Trichosporon sp., Mortierella sp. and Candida sp.. One bacterial and two

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TALKS - PATHOGENESIS fungal isolates: Arthrobacter sp. (MB 109), Cryptococcus sp. (MF 21) and Mucor sp. (MF 83) were inoculated in microcosms with C-rich black slate (106 ± 7 g/kg). U and V were immobilized by Arthrobacter sp., indicating an active biological process. In addition, the Ra activity concentrations in the water phase were increasing, showing direct or indirect impact of microorganisms on radionuclide mobilization in water-rock-interactions. To verify this result, further measurements of radionuclide activity are required and still in process.

Pathogenesis session Fingerprinting of Candida spp. blood infections Philipp Kämmer [1], Sylvie Schulze [2], Thomas Wolf [2], Kerstin Hünniger [3], Jörg Linde [2], Oliver Kurzai [3], Reinhard Guthke [2], Bernhard Hube [1,4,5], Sascha Brunke [1] [1] Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany [2] Research Group Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany [3] Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany [4] Center for Sepsis Control and Care, University Hospital Jena, Germany [5] Friedrich Schiller University, Jena, Germany

Candida species are one of the most common causes of invasive fungal infections. Among them, Candida albicans, C. glabrata, C. parapsilosis, and C. tropicalis account for about 90 % of all systemic Candida infections [1]. We established an ex vivo whole blood infection model mimicking the initial phase of a systemic Candida infection. Interdependent transcriptional responses have been investigated, based on a dynamic dual-species RNAseq approach of both human host and fungal pathogen. Our first results revealed a predominantly uniform human response to infection with the four species, with only few species-specific regulations. This time-dependent human transcriptional changes are governed by immune system processes, in particular by genes involved in TNF and NF-kB signaling. In contrast, the individual Candida species seem to pursue predominantly individual strategies to survive the harsh bloodstream environment: while the three closely related species C. albicans, C. tropicalis, and C. parapsilosis each regulate a noticeable fraction of their genomes in response to blood exposure, C. glabrata reacts with only minor transcriptional adjustments to this new milieu. The shutdown of protein biosynthesis and the activation of heat shock responses were found to be common fungal responses. In contrast, genes involved in oxidative stress response are comprehensively up-regulated by C. albicans, C. tropicalis, and C. parapsilosis, but not by C. glabrata. Further processes, like iron homeostasis or cell cycle progression, are even more species-specifically regulated. Gene regulatory networks based on these datasets have been generated to provide insight into the interdependency of host and pathogen transcriptomes. These will improve our understanding of the biology of disseminating Candida infections and will help to identify both general and species-specific transcriptome markers. [1] Guinea, J. (2014) Global trends in the distribution of Candida species causing candidemia. Clin Microbiol Infec, 20 Suppl 6:5-10. doi: 10.1111/14690691.12539.

Towards understanding the intraphagocytic long term survival of Lichtheimia corymbifera Mohamed Abdelwahab Hassan [1], Hea Reung Park [1], Volker Schwartze [1], Benjamin Hanf [2], Gabor Nagy [3], Árpád Csernetics [3], Tamas Papp [3], Thomas Krüger [2], Jakob Weber [2], Christine Skerka [4], Olaf Kniemeyer [2], Axel A. Brakhage [2], Peter F. Zipfel [4], Kerstin Voigt [1] [1] Leibniz-Institute for Natural Product Research and Infection Biology, Jena Microbial Research Collection, Jena, Germany

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[2] Leibniz-Institute for Natural Product Research and Infection Biology, Molecular and Applied Microbiology, Jena, Germany [3] University of Szeged, Faculty of Science and Informatics, Department of Microbiology, Szeged, Hungary [4] Leibniz-Institute for Natural Product Research and Infection Biology, Infection Biology, Jena, Germany

Mucoralean fungi can cause mucormycosis, a life-threatening disease in immunocompromised patients. In our study, we analysed the influence of different enzymatic treatments of the spore surface alterations on the phagocytosis by murine alveolar macrophages. Two strains which were shown to be virulent and attenuated in avian, invertebrate and murine infection models were used in this study. The spore surface was treated with different cell wall-degrading cell wall enzymes targeting carbohydrate and protein cell wall components. The highest phagocytosis index was achieved with the proteolytic treatments which encouraged us to investigate the long term survival of treated spores inside the macrophage and to focus our research on the protein surface of spores. Proteomic analysis of the spore surface was conducted for both strains. About four-teen candidate proteins were found which were differentially abundant in either the virulent strain or in the attenuated strain leading to the hypothesis that these proteins may play a role in virulence. Two hydrophobic surface binding proteins A (HsbA) are the concern of our study, which of one was first found in higher abundance on the spore surface of in the virulent strain and the other one on the spore surface of the attenuated strain of L. corymbifera. The HsbA proteins from the virulent and attenuated strain of L. corymbifera were heterologously overexpressed in Pichia pastoris. After pretreatment of murine alveolar macrophages and spores with purified fractions of the HsbA protein of the virulent strain, the phagocytic index was found to be enhanced in comparison with non-stimulated host cells. The invasion assays for the Pichia mutants which overexpress the HsbA proteins of both strains of L. corymbifera are ongoing. The findings presented in this study will open the door for the role of surface proteins in the recognition of L. corymbifera by phagocytes of the innate immune system which raise important measures to mammalian infection models. Our prospect for the future research will focus on the identification of potential stimulatory effects of L. corymbifera surface proteins and their putative receptors on the surface of macrophages which possibly contribute to virulence. Candida albicans battle against Dectin-1 and Dectin-2 host-mediated immune response Nadine Reiher [1], Peter F. Zipfel [2] [1] Center for Sepsis Control and Care Jena, Leibniz Institute for Natural Product Research and Infection Biology Jena [2] Leibniz Institute for Natural Product Research and InfectionBiology Jena, Friedrich-Schiller-University Jena

Candida albicans is a dimorphic fungus which colonizes the skin and mucosal surfaces of the human host and which mostly exists as a harmless commensal. However, in immunocompromised individuals candida can induce severe systemic infections that can cause sepsis with poor outcome. In general terms the innate immune system is central for the immediate recognition and safe elimination of pathogenic microbes. Therefore immune cells express a broad range of pattern-recognition-receptors (PRRs). These PRRs bind to highly conserved pathogen-associatedmolecular-patterns (PAMPs), which are shared by a number of microbial pathogens. Dendritic cells (DCs), which link the innate to the adaptive immune system, express these PRRs and the Ctype-lectin receptors Dectin-1 and Dectin-2. These receptors recognize β-glucan and mannan, the major components of the candida cell wall. Dectin-1 and Dectin-2 recognition is important for the host antifungal immune response and normally results in the elimination of the fungal invader. C. albicans has developed efficient strategies to shield its surface from recognition by the host PRRs. Thereby the pathogen blocks the recognition by the immune cells and modulates the immune response to survive in the host. It is the aim of this project to characterize how C. albicans evades the recognition by Dectin-1 and Dectin-2 on human DCs. We are analyzing general features of the

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TALKS - PATHOGENESIS fungal counterstrike to Dectin-mediated pattern recognition. We have identified a new candida protein, i.e. CRASP11, which binds to both Dectin-1 and Dectin-2 on human DCs and modulates the inflammatory immune response. CRASP11 induces secretion of anti-inflammatory IL-10 and simultaneously down-regulates the expression of pro-inflammatory cytokines TNF-α and IFN-γ. Furthermore CRASP11 blocks LPS induced activation and maturation of dendritic cells and down regulates the expression of the maturation markers CD80, CD83 and CD86 to generate an immunosuppressive phenotype in DCs. Hypoxia influences the C. albicans - enterocyte interaction Nicole Engert [1], Rebecca Mikolajczyk [1], Elisabeth Gressler [1], Ilse D. Jacobsen [1,2,3] [1] Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany [2] Friedrich-Schiller University Jena, Germany [3] Center for Sepsis Control and Care (CSCC), University Hospital Jena, Germany

The opportunistic fungal pathogen Candida albicans frequently occurs as commensal in the gastrointestinal tract of humans. While it is known that intestinal epithelial cells are highly sensitive to ischemic hypoxia, the role of hypoxia-mediated damage in the translocation of C. albicans through the intestinal barrier, potentially leading to life-threatening systemic infections, is unclear. Thus, we characterised enterocyte-C. albicans interactions under normoxic and hypoxic conditions. When enterocytes were shifted from low to higher O2 levels (reperfusion) for the time of infection, C. albicans -mediated damage increased significantly, especially for O2 levels ≤ 2 %. Surprisingly, shifting the cells from ambient or physiological conditions to lower O2 levels (hypoxic shock) immediately before infection led to reduced damage. Subsequent reperfusion after exposure to hypoxic shock (1 % O2 ) for 2 h abolished the protective effect of hypoxic shock and increased damage of infected enterocytes. Supporting these data, the invasion potential of C. albicans and the permeability of infected enterocytes was exclusively increased at reperfusion whereas hypoxic shock conditions increased fungal adhesion. Consistent with these results, trans-epithelial electrical resistance (TEER) remained stable during infection at hypoxic shock but decreased continuously for all other conditions. TEER values for uninfected enterocytes showed no significant differences between the tested O2 conditions. Strikingly, ROS levels of both infected and non-infected enterocytes were increased at hypoxic shock conditions but not at reperfusion. In ongoing experiments we aim to analyse the infection process in more detail to determine the mechanisms that lead to increased damage during reperfusion. This includes analysis of the expression of tight junction proteins, the role of hypoxia-inducible factor 1 (HIF-1α) for protection during hypoxic shock and transcriptional profiling to identify further O2 -induced changes in enterocytes contributing to infection susceptibility. The role of secreted Ece1 peptides in Candida albicans – macrophage interaction Annika Franke [1], Lydia Kasper [1], Selene Mogavero [1], Bernhard Hube [1,2,3] [1] Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Department of Microbial Pathogenicity Mechanisms, Jena, Germany [2] Center for Sepsis Control and Care, University Hospital Jena, Jena, Germany [3] Friedrich Schiller University, Jena, Germany

Candida albicans, an opportunistic human pathogen, uses different strategies to evade or adapt to phagocyte antimicrobial activities and to survive phagocytosis. Phagocytosis of C. albicans yeasts by macrophages induces filamentation, which results in escape of the fungus from these immune cells and host cell damage. Besides this, hypha formation is connected with induction of proinflammatory cytokines in these immune cells. We investigate ECE1, a hypha-associated gene, which is highly upregulated during filamentation of C. albicans. The encoded protein Ece1 is a

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polypeptide comprised of eight peptides (I-VIII), of which peptide III (Candidalysin) is capable of producing lesions in host cell membranes [1]. Besides Candidalysin, almost all other Ece1 peptides are secreted upon hypha formation, as revealed by LC/MS analysis [1]. ECE1 itself is dispensable for phagocytosis of C. albicans, subsequent filamentation in and hyphal outgrowth from macrophages. However, the secreted peptide toxin Candidalysin is involved in immune cell death and NLRP3-inflammasome activation. Ongoing research is focusing on the role of nonCandidalysin Ece1 peptides during the interaction of C. albicans with host cells. To address this, the effect of single peptide knockouts on fungal infectivity, as well as the impact of synthetic peptides on the infection process will be monitored. Preliminary data show that peptide V, one of the most abundant secreted Ece1 peptides[1], induces pro-inflammatory cytokine induction by macrophages, thus highlighting the importance of non-Candidalysin peptides during the fungushost interaction. Concluding, we propose a dual function of Ece1: Candidalysin-mediated lesion formation is beneficial for C. albicans immune evasion by providing an escape route for the fungus, but might as well contribute to antifungal host defense through activation of pro-inflammatory pathways. Non-Candidalysin Ece1 peptides might facilitate the Candidalysin action, but might as well possess an independent role during the infection process. [1] Moyes et al. 2016, Candidalysin is a fungal peptide toxin critical for mucosal infection, Nature 532, pp. 64-68.

The role of auxins in the interaction of plant and a hemibiotrophic fungal pathogen Leptosphaeria maculans Hana Krutinová [1,2], Vladimír Matˇej Šašek [1,3], Petre Ivanov Dobrev [1], Lucie Trdá [1], Lenka Burketová [1] [1] Institute of Experimental Botany AS CR, Laboratory of pathological plant physiology, Prague, Czech Republic [2] Faculty of Science, Charles University, Prague, Czech Republic [3] Science Farm Rantíˇrov,Czech Republic

Phytohormones are small molecules essential for coordination of plant life processes including defence signaling. Plant pathogens have developed strategies to overcome plants defence by altering hormone signaling either by manipulating host signaling pathways or producing their own phytohormones. Auxins are well characterized group of phytohormones. Besides their essential role in plant growth, auxins are involved in cross-talks with the main defence phytohormones, such as jasmonic acid and salicylic acid. In consequence, activated auxin signaling alters resistance against pathogens[1]. Many pathogens are known to produce auxins as a factor of virulence. It has been shown that increased auxin synthesis leads to increased virulence of fungi [2,3]. Other pathogens produce effectors that affect auxin transport and signaling in plants [4]. In our laboratory we study the interaction of the oilseed rape (Brassica napus) and its economically most important pathogen Leptosphaeria maculans and the underlying phytohormone signaling. The ability of L. maculans to produce auxins was studied. L. maculans liquid culture was treated with biosynthetic precursors and auxin concentration was determined by LC-MS. Precursors stimulated IAA biosynthesis already several hours after application and putative auxin biosynthesis genes were identified in L. maculans genome based on orthology with previously identified genes [5-7]. The time-course of their expression following precursor application was measured by RT-qPCR. Responsive genes were silenced using RNAi gene silencing technology and prepared mutant lines were screened for altered auxin profile. Four mutant lines with decreased IAA production were identified and their virulence and altered host plant responses are being tested. [1] Pieterse, C.M.J. et al., Zamioudis, C., Leon-Reyes, A., Van Wees, S. C. M. (2012). Hormonal modulation of plant immunity. Annual review of cell and developmental biology, 28, 489-521. [2] Yang, S., Zhang, Q., Guo, J., Charkowski, A. O., Glick, B., R., Ibekwe, M., A., Cooksey, D. A.,Yang, C.-H. (2007). Global effect of indole-3-acetic acid biosynthesis on multiple virulence factors of Erwinia chrysanthemi 3937. Applied and Environmental Microbiology, 73(4), 1079-1088. [3] Cohen, B. A., Amsellem, Z., Maor, R., Sharon, A. and Gressel, J. (2002). Transgenically enhanced expression of

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TALKS - PATHOGENESIS indole-3-acetic acid confers hypervirulence to plant pathogens. Phytopathology, 92(6), 590-6. [4] Kazan, K. & Lyons, R., (2014). Intervention of phytohormone pathways by pathogen effectors. The Plant cell, 26, 1-26. [5] Reineke, G., Heinze, B., Schirawski, J., Buettner, H., Kahmann, R., Basse, C. W. (2008). Indole-3-acetic acid (IAA) biosynthesis in the smut fungus Ustilago maydis and its relevance for increased IAA levels in infected tissue. Molecular plant pathology, 9, 339-355. [6] Tivendale, N.D., Ross, J.J. & Cohen, J.D., (2014). The shifting paradigms of auxin biosynthesis. Trends in Plant Science, 19(1), 44-51. [7] Brandl, M. and Lindow, S. E.(1997) Environmental signals modulate the expression of an Indole-3-acetic acid biosynthetic gene in Erwinia herbicola. Molecular Plant-Microbe Interactions, 10(4), 499-505.

Candida albicans colonization of the murine gut does not depend on filament maintenance and cell damage Sven Rudolphi [1], A. Elisabeth Gressler [1], Ilse D. Jacobsen [1,2,3] [1] Research Group Microbial Immunology - Leibniz Institute for Natural Product Research and Infection Biology Hans Knoell Institute, Jena, Germany [2] Friedrich-Schiller-University Jena, Jena, Germany [3] Center for Sepsis Control and Care, Jena, Germany

Candida albicans frequently occurs as a commensal on mucosal surfaces of humans. Under predisposing conditions, this colonization, can lead to dissemination and life-threatening systemic disease. Because the mechanisms facilitating colonization and mediating dissemination are only poorly understood, we used a murine colonization/dissemination model to (i) characterize colonization and (ii) determine whether hypha formation, a hallmark of C. albicans virulence in invasive infections, and candidalysin-mediated cell damage are required for colonization. Animals remained clinically healthy throughout the experiments. All fungal morphologies, including hyphae, were found in the content and homogenates of the stomach, small intestine, cecum and colon at different time points after infection. Fecal fungal burden remained stable time over time as long as antibiotic depletion of bacteria was maintained. In contrast, in vivo imaging revealed a rather dynamic behavior with changing intensity and localization of signals. Furthermore, ex vivo imaging revealed distinct foci of bioluminescent signals in the gastrointestinal tract, suggesting enhanced colonization and/or local infection. However, no distinct immune response was observed within foci compared to nonluminescent intestinal sections. Upon colonization with C. albicans, the immune response was altered in a strain-unspecific fashion with decreasing absolute cell numbers and increasing B and NK cell proportions. To determine the role of hyphae for colonization, C. albicans mutants deficient for either EED1 (hyphal maintenance) or ECE1 (candidalysin-mediated cell damage) were tested. To our surprise, neither affected colonization levels in single colonization. In a competition model, the ECE1 mutant was outcompeted by the wildtype. Thus, C. albicans stably colonized the whole murine gastrointestinal tract during antibiosis and colonization is independent of hyphal maintenance and candidalysin-mediated cell damage.

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Chemical ecology session Small changes with big consequences: variation in a key gene structures herbivore communities and determine plant performance Nora Adam [1], Mario Kallenbach [1,3], Stefan Meldau [1,4], Ian T. Baldwin [1], Meredith C. Schuman [1] [1] Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena, Germany [2] German Centre for Integrative Biodiversity Research (iDiv), Leipzig, Germany [3] Shimadzu Deutschland GmbH, Technisches Büro Jena, Jena, Germany [4] KWS SAAT AG, Einbeck, Germany

Host plant genetic diversity structures animal communities, but the mechanisms remain largely unexplored. Here, we ask what effects can be observed when varying the expression of a single gene, the jasmonate (JA) defense hormone biosynthetic gene lipoxygenase 3 (LOX3), in experimental communities of three naturally co-occurring herbivores: the generalist Empoasca sp. (Hemiptera: Cicadellidae), and two specialists, Tupiocoris notatus (Hemiptera: Miridae) and Manduca sexta larvae (Lepidoptera, Sphingidae); with their native host, the wild tobacco Nicotiana attenuata (Solanaceae). In nature, Empoasca sp. attacks JA-deficient N. attenuata plants, and T. notatus avoids Empoasca sp.-infested plants. However in mixed populations having equal numbers of wild-type (WT) and as LOX3 plants, Empoasca sp. feeding was distributed between plant genotypes. Empoasca sp. damage, rather than JA, determined T. notatus damage, which was lower in mixed populations. Growth of M. sexta larvae was lower on WT monocultures than as LOX3 but only differed from mixed cultures when caterpillar density was high. WT plants in mixed cultures produced more seed capsules than those in monocultures, while seed production of as LOX3 plants did not differ by population type. However, at low caterpillar density, as LOX3 plants growing in mixed populations produced more seed capsules than those growing in monoculture, while production did not differ for WT by population type. Thus, mixed populations had a more stable output of seed capsules under two scenarios. This might result from a balance of susceptibility to herbivores versus competitive ability, which are differently regulated by JA signaling. Ratiometric gas reporting: a new approach to monitor microbial cell-cell signaling in soils Hsiao-Ying Cheng [1], Caroline A. Masiello [2], Ilenne Del Valle [3], Jonathan J. Silberg [1,4] [1] Department of Bioengineering, Rice University, Houston, TX, USA [2] Department of Earth Science and Department of Chemistry, Rice University, Houston, TX, USA [3] System Synthetic and Physical Biology Program, Rice University, Houston, TX, USA [4] Department of Biosciences, Rice University, Houston, TX, USA

Microbes make population-dependent decisions by monitoring the accumulation of chemicals that they synthesize. The accumulation of these chemicals regulates diverse microbial processes, such as virulence, biofilm formation, and symbiosis, and has large-scale implications for agricultural outcomes and biogeochemical cycling. However, little is known about how the dynamics of cell-cell signaling vary across different soil conditions. While microbial biosensors have been used to detect population-dependent decision making previously, existing visual reporters have limited utility for in situ measurements in soils. To overcome this limitation, we used gas-producing enzymes as a new class of reporters, which generate diffusible gases and can be quantified by a gas chromatography without further sample preparation. Using this new method, we developed microbial biosensors to detect different acylhomoserine lactones (AHLs), chemical communication signals used by soil bacteria. We designed the biosensors with a two-gas reporting system where one gas is constitutively produced to provide information on the number of viable biosensors, and the production of a second gas is coupled to the concentration of AHLs using AHL-dependent transcriptional regulators. We show that the ratio of these gases can be used to quantify two AHLs ( 3-oxo-C6HSL and 3-oxo-C12HSL) in a liquid medium and in soils at 85% water holding capacity.

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TALKS - CHEMICAL ECOLOGY We also used these biosensors to non-disruptively monitor AHL degradation by abiotic or biotic factors and AHL production by rhizobia in soils. R atiometric gas reporting enables the quantification of AHL by normalizing the inducible gas signal to the number of the microbial biosensors, and it provides a simple approach to study how soil conditions affect the bioavailability of AHL. With further development, this gas reporting method can become a generalizable alternative to study microbial gene expression within soil where visual reporters are not compatible. Syntrophic interactions in a dechlorinating co-culture of Sulfurospirillum multivorans and Dehalococcoides mccartyi Stefan Kruse [1], Tobias Goris [1], Dominique Türkowsky [2], Nico Jehmlich [2], Lorenz Adrian [3], Martin Westermann [4], Gabriele Diekert [1] [1] Friedrich Schiller University, Institute of Microbiology, Dept. of Applied and Ecological Microbiology, Jena, Germany [2] Helmholtz Centre for Environmental Research - UFZ, Dept. of Molecual Systems Biology, Leipzig, Germany [3] Helmholtz Centre for Environmental Research - UFZ, Dept. of Isotope Biogeochemistry, Leipzig, Germany [4] Center for Electron Microscopy of the University Hospital Jena, Jena, Germany

Syntrophic communities are characterized by various microbial interactions based on an exchange of metabolic products. Hydrogen plays a crucial role and is transferred in an interspecies hydrogen transfer1. In dechlorinating communities, hydrogen is produced by fermentative organisms and is used as electron donor for the dechlorination of chlorinated ethenes, catalyzed by corrinoiddependent reductive dehalogenases. Many versatile, fast-growing PCE-dechlorinating bacteria, like the Epsilonproteobacterium Sulfurospirillum multivorans, are only able to dechlorinate PCE to the harmful dichloroethene (DCE) [2]. Complete dechlorination to ethene is mainly achieved by Dehalococcoides mccartyi, a bacterium characterized by its obligate organohalide-respiratory lifestyle and its slow growth. Hydrogen is the only electron donor used by D. mccartyi in this process. Previous studies showed, that co-cultures of D. mccartyi with other bacteria showed better growth and faster dechlorination rates than in pure cultures3. In this study, we set up co-cultures of D. mccartyi with the recently shown hydrogen producer S. multivorans. Co-cultures amended with lactate as carbon and energy source and PCE as electron acceptor showed complete dechlorination of PCE to ethene, indicating hydrogen transfer from S. multivorans to D. mccartyi. On lactate alone, S. multivorans showed no growth. Since D. mccartyi relies on H2 as electron donor, this result implies an obligate syntrophic interaction between the two organisms. PCE to ethene dechlorination rates were more than twice as fast as in pure cultures. Besides hydrogen, also corrinoid was shown to be transferred, as reductive dechlorination occurred not in vitamin B12 -free single cultures, but only in co-cultures. This study gives first insights for a better understanding of bioremediation processes in soil habitats and metabolite fluxes in dechlorinating communities. [1] Schink and Stams, Syntrophism among Prokaroytes , in „The Prokaryotes" (2013), ISBN: 978-3-642-30122-3 [2] Neumann et al., Arch. Microbiol. (1994), doi: 10.1007/BF00301854 [3] Mao et al ., AEM (2015), doi: 1 0.1128/AEM.03464-14

Defense signaling in poplar (Populus sp.) against biotrophic rust fungus Melampsora laricipopulina Chhana Ullah [1], Chung-Jui Tsai [2], Sybille Unsicker [1], Jonathan Gershenzon [1], Almuth Hammerbacher [1] [1] Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany [2] Department of Genetics, University of Georgia, Athens, Georgia, USA

Woody-perennial Populus spp. synthesizes flavan-3-ols such as catechin and proanthocyanidins (PAs) as an effective antifungal defense against rust fungus M. larici-populina . So far, the hormonal regulations of these defense reactions are mostly unknown during poplar-rust interactions. Here,

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we investigated the role of phytohormones in the regulation of poplar defense against rust fungus. We profiled the amounts of major defense hormones in black poplar (P. nigra) leaves after rust inoculation over the course of infection. P. nigra increased the levels of salicylic acid (SA) in rustinfected leaves compared to the corresponding control plants, and activated classical signaling downstream of SA. Interestingly, the increased levels of SA were correlated with the accumulation of defense compounds such as catechin and PAs. Exogenous spraying with SA analogue, benzothiadiazol (BTH), in poplar leaves before rust inoculation, increased levels of antimicrobial flavan-3-ols and reduced the colonization of rust fungus. These findings suggest that there is a strong connection between SA signaling and flavan-3-ol biosynthesis in poplar. We also analyzed SA over-expressing transgenic poplars and found that these plants constitutively accumulated more flavan-3-ols. Taken together, our data indicate that SA triggers biosynthesis of flavan-3-ols and PAs in poplar.

Natural products session Functional and chemical analysis of Actinobacteria associated with fungus-growing termites René Benndorf [1], Huijuan Guo [1], Elisabeth Sommerwerk [1], Christiane Weigel [2], Saria Otani[3], Michael Poulsen [3], Christine Beemelmanns [1] [1] Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute, Chemical Biology of Microbe-Host Interactions, Jena, Germany [2] Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute, Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute, Jena, Germany [3] University of Copenhagen, Department of Biology, Section for Ecology and Evolution, Copenhagen, Denmark

Introduction: Macrotermitinae (fungus-growing termites) cultivate a mutualistic food fungus (Termitomyces sp.) for nourishment in so called “fungus gardens”,[1] a nutrient-rich environment prone to exploitation. Symbiotic and associated bacteria are assumed to play a major role in the defense of the fungus garden by secretion of antimicrobial small molecules, which selectively target garden parasites and other invading species.[2] Objectives: We focus on the functional, genomic and chemical analysis of Actinobacteria associated with fungus growing termites to study their role as defensive symbionts. Methods: Using different culture-depended methods, we first isolated Actinobacteria from various different insect body parts. Using the obtained isolates, we then performed different activity assays to investigate the (selective) inhibition of fungal garden parasites. Strains with particular high antifungal activity were selected for further chemical analysis. Dereplication was performed using MS-based techniques. The produced antimicrobial secondary metabolites were analyzed and characterized using HPLC/LC-HRMS/NMR. In parallel, we sequenced selected isolates to investigate the strains on genomic level. Results: Using selective culture medium, more than 100 different members of Actinobacteria phylum were isolated from different body parts of termite workers and the termite nest.[3] Extracts of the bacteria culture were tested against known human pathogens showing a high antimicrobial activity. Pairing challenging assays of Actinobacteria extracts showed activity against co-isolated and antagonistic fungi, such as Pleosporales sp. Several new metabolites were identified and characterized. We are now developing a culture-independent approach to describe and analyze the antimicrobial environment, which antagonist’s meet when entering the nest. Conclusion: Microbial symbionts and commensals most likely contribute to the fungus garden homeostasis by secretion of antimicrobial compounds. [1] a) Aanen, D. K.; Eggleton, P.; Rouland-Lefèvre, C.; Guldberg-Frøslev, T.; Rosendahl, S.; Boomsma, J. J. Proc. Natl. Acad. Sci. U. S. A . 2002, 99 , 14887 - 14892; b) Poulsen, M.; Hu, H.; Li, C.; Chen, Z.; Xu, L.; Otani, S.; Nygaard, S.; Nobre, T.; Klaubauf, S.; Schindler, P. M.; Hauser, F.; Pan, H.; Yang, Z.; Sonnenberg, A. S. M.; de Beer, Z. W.; Zhang, Y.; Wingfield, M. J.; Grimmelikhuijzen, C. J. P.; de Vriese, R. P.; Korb, J.; Aanen, D. K.; Wang, J.;

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TALKS - NATURAL PRODUCTS Boomsma, J. J.; Zhang, G. Proc. Natl. Acad. Sci. U. S. A . 2014, 111, 14500-14505. [2] a) Beemelmanns C., Guo H., Rischer M., Poulsen M. Beilstein J Org Chem 2016 12, 314-327; b) Ramadhar, T. R; Beemelmanns, C.; Currie C. R.; Clardy J. J Antibiot (Tokyo) 2014, 67(1), 53-58. [3] Visser, A. A.; Nobre, T.; Currie, C. R.; Aanen, D. K.; Poulsen, M. Microb. Ecol. 2012, 63, 975-985.

Pyreudiones: Novel Bacterial Amoebicides Produced by a Monomodular Nonribosomal Peptide Synthetase Martin Klapper, Sebastian Götze, Robert Barnett, Daniel Braga, Karsten Willing, Gerald Lackner, Pierre Stallforth Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Jena, Germany

Bacteria are constantly exposed to a multitude of threats: bacteriophages can infect and kill bacteria; amoebae, nematodes, and insects can prey on prokaryotes, and competitor strains fight for the same resources. In order to survive in this battlefield, bacteria have evolved highly effective defense mechanisms. [1,2] Because killing and deterring the antagonists are powerful ways to thrive in this environment, bacteria display a great diversity of toxins and antibiotics that selectively act on their enemies. Amoebae are voracious and ubiquitous predators to bacteria that cause constant depletion of huge bacterial reservoirs. This puts both organisms under strong evolutionary selection pressure: the bacteria have evolved mechanisms to prevent grazing and the amoebae must counteract or surmount these mechanisms in order to survive. [3] We focus on the interactions between the eukaryotic soil amoeba Dictyostelium discoideum and various soil bacteria. We isolated one particular Pseudomonas fluorescens strain from forest soil, which displays great toxicity against D. discoideum. Bioassay-guided fractionation allowed the identification of amoebicidal natural products. The discovered pyreudiones bear a tetramic acid moiety and belong to the class of bacterial pyrrolizidine alkaloids. Their structures were elucidated by spectroscopic methods and chemical synthesis. Whole genome sequencing of the producer strain allowed identifying the biosynthetic gene – a monomodular nonribosomal peptide synthetase (NRPS). Generation of gene deletion mutants unable to produce the pyreudiones showed that these toxins are sufficient and necessary to prevent amoebal predation. [4] [1] M. J. Pallen, B. W. Wren, Nature 2007, 449 , 835. [2] M. Erken, C. Lutz, D. McDougald, Microb. Ecol. 2013, 65 , 860. [3] H. Hilbi, S. S. Weber, C. Ragaz, Y. Nyfeler, S. Urwyler, Environ. Microbiol. 2007, 9, 563. [4] M. Klapper, S. Götze, R. Barnett, K. Willing, P. Stallforth, Angew. Chem. Int. Ed. 2016, 55, 8944-8947.

pL-Droplets as novel vessels for ultra-high throughput cultivation and screening of microbial cells Lisa Mahler, Miguel Tovar, Thomas Weber, Oksana Shvydkiv, Karin Martin, Christine Beemelmanns, Emerson Zang, Martin Roth Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute – Jena, Germany

Droplet microfluidics will be the game-changer in classic cell-based screens, presenting a 1,000,000 fold miniaturization of an MTP-well and allowing throughput rates of 1000 Hz [1]. With its fast and stable aqueous droplets, that serve as picoliter bioreactors for highly parallelized cultivation of microbial cells, droplet microfluidics possesses the potential to give the field of natural product discovery new momentum. Our efforts are aimed at further optimizing droplets as a comprehensive platform for microbial experimentation, since limitations like inappropriate oxygen supply during droplet incubation and restriction to fluorescence based read-outs still exist. Recently, we developed a dynamic droplet incubation system that provides sufficient and homogeneous oxygen supply for millions of droplets simultaneously, resulting in successful cultivation of a diverse set of microbial species, including obligate aerobes like Pseudomonas fluorescens and fastidious actinobacteria [2]. Optimization of this ultra-high throughput method for cultivation of microbial cells

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allows us to exploit the vast diversity of naturally occurring bacterial species and their metabolites derived from various natural habitats. By compartmentalizing single cells in droplets, commonly underrepresented species like slow growing organisms, can be targeted, since competition for nutrients is prevented. Thereby a new subset of yet uncultivated species is made accessible for cultivation and subsequent investigation. By adding reporter strains, which indicate the presence of inhibiting secondary metabolites, we can screen immediately for antibiotics. First experiments revealed a production of various antimicrobial substances in significant amounts and a reliable differentiation between inhibiting and non-inhibiting droplet content. Thus, natural product discovery will soon benefit from the ultra-high throughput of droplet microfluidics. [1] Agresti, J. J., Antipov, E., Abate, A. R., Ahn, K., Rowat, A. C., Baret, J.-C., ... Weitz, D. A. (2010). Ultrahighthroughput screening in drop-based microfluidics for directed evolution. Proceedings of the National Academy of Sciences of the United States of America, 107 (9), 4004–4009. [2] Mahler, L., Tovar, M., Weber, T., Brandes, S., Rudolph, M. M., Ehgartner, J., ... Zang, E. (2015). Enhanced and homogeneous oxygen availability during incubation of microfluidic droplets. RSC Advances, 5 (123), 101871101878.

Systems biology session From dual RNA-Seq data to inter-species gene regulatory networks: computational prediction of molecular host-pathogen interactions Thomas Wolf [1], Sylvie Schulze [1], Philipp Kämmer [2], Sascha Brunke [2], Bernhard Hube [2], Reinhard Guthke [1], Jörg Linde [1] [1] Research Group Systems Biology / Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute (HKI), Jena, Germany [2] Department Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute (HKI), Jena, Germany

Organisms constantly react to abiotic and biotic changes by adapting their gene expression, which is modulated by complex gene regulatory networks (GRNs). While knowledge about these networks is helpful to understand adaptation processes and identify key regulators, it is often sparse. Network inference is a powerful method which has been successfully applied to predict GRNs from transcriptome data. With the advent of dual RNA-Seq techniques, it is now possible to simultaneously monitor the transcriptome of host and pathogen without the need to physically separate cells or RNA-species. The tool “NetGenerator” [1] infers GRNs from time-resolved gene expression data. The resulting network is described by ordinary differential equations and depicted as directed graph. Here we present our extended version of NetGenerator for dual RNASeq data, with the goal to predict molecular host-pathogen interactions. First, NetGenerator is now able to model mutual stimulations with two or more stimuli. Next, it can handle missing values. Finally, it will correctly handle the influence of sample variation and noise. The result of all these improvements is a more realistic representation of the underlying biology, which translates into the prediction of more reliable interactions. We demonstrate the application of the new NetGenerator version to dual RNA-Seq data of human blood infected with C. albicans. Analysing this dataset, we predicted two host-pathogen interaction networks. One network deals with the battle for iron, the other with oxidative stress response. Notably, the iron network demonstrated that in blood the gene ALS3 from C. albicans positively influences the expression of the gene MFI2 , which is coding for Melanotransferrin in human. Moreover, in the oxidative stress network, the the fungal gene SOD5 influences the human gene IL1B. This demonstrates that our approach is able to predict meaningful molecular host-pathogen interactions - now awaiting experimental validation. [1] Schulze et al. (2015). Computational prediction of molecular pathogen-host interactions based on dual transcriptome data. Frontiers in Microbiology

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TALKS - SYSTEMS BIOLOGY Insights into the mode of action of sepsis biomarker CAAP48 in human neutrophils using Raman spectroscopy Natalie Töpfer [1,2], Nancy Blaurock [3], Diana Schmerler [3], Anuradha Ramoji [1,2], Marcel Dahms [1,2,6], Oliver Kurzai [4], Jürgen Popp [1,2,5,6], Michael Kiehntopf [1,3], Ute Neugebauer [1,2,5,6] [1] Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany [2] Leibniz Institute of Photonic Technology, Jena, Germany [3] Department of Clinical Chemistry and Laboratory Medicine, Jena University Hospital, Jena, Germany [4] Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural product Research and Infection Biology - Hans Knoell Institute, Jena, Germany [5] Institute for Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Jena, Germany [6] InfectoGnostics Research Campus Jena, Reg. Assoc., Jena, Germany

In case of patients with systemic inflammatory response syndrome due to noninfectious (SIRS) and infectious (sepsis) origin, a fast and clear diagnosis is crucial. A new sepsis marker peptide called CAAP48 has been identified which is present in 3-4 fold higher concentration in sepsis patients than in SIRS patients [1]. The peptide has been found to trigger proinflammatory cytokine and reactive oxygen species (ROS) release in immune cells. CAAP48-treated human polymorphonuclear granulocytes (PMN) showed surface activation and reduced viability. The mode of action of this peptide is still unknown and investigations are being carried out to understand the host response. As a label-free method Raman spectroscopic imaging was applied to gain further insights into the biochemical changes of human neutrophils induced by CAAP48. PMN were isolated from human blood of healthy volunteers and incubated with PBS (NC), phorbol 12-myristate 13-acetate (PMA), synthetic CAAP48, a less active derivative CAAP47 and a non-activating scrambled peptide (SP) with same amino acids, but at random sequence. After 30 min incubation cells were fixed and high resolution Raman scans were recorded. Statistical data analysis, including classification models and spectral unmixing, indicates a loss in DNA and increase in protein in CAAP48-cells. A detected increased Phe-peak at 1001 cm-1 has been observed in necrotic and early apoptotic cells [2]. A classification model was able to identify CAAP48-PMN from NC-PMN with 100% accuracy and from CAAP47-PMN with 95% accuracy. PMA-PMN could be clearly distinguished from the CAAP48-, but not from the CAAP47-group. Cells incubated with SP did not show any distinct differences compared to untreated cells. Raman classification models indicate a different activation mode and level induced by CAAP48 than by PMA. Raman image analysis shows that the nuclei are often degraded. The gained knowledge could help to identify cells influenced by CAAP48 in sepsis patients. [1] Blaurock et al. (2016). Mediators of Inflammation [2] Brauchle et al. (2014). Scientific Reports

Alternative splicing of Aspergillus fumigatus during interaction with human neutrophils Patricia Sieber [1,2], Stefan Schuster [1], Reinhard Guthke [2], Jörg Linde [2] [1] Department of Bioinformatics, Faculty of Biology and Pharmacy, Friedrich Schiller University Jena, Jena, Germany [2] Research Group Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Jena, Germany

Alternative splicing (AS) increases the functional complexity of organisms. Though AS is common in all eukaryotes, still little is known about its impact in fungi [1]. A. fumigatus is a major fungal pathogen and of high clinical interest. Humans daily inhale thousands of fungal spores causing no harm in immunocompetent individuals. However, in immunocompromised patients A. fumigatus may cause severe systemic infections with mortality rates up to more than 90% [2]. Neutrophils play an important role in innate immunity. The presented work aims at better understanding the role of AS in the human-pathogenic fungus A. fumigatus during interaction with

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human neutrophils. We analyzed time series RNA-Seq data of A. fumigatus in a coculture with human neutrophils. First, we identified 2783 differentially expressed genes (DEG) using the tools DESeq and edgeR. Next, we used different AS detection tools and filtered results to identify significantly differentially spliced genes (DIS). In sum, we detected 18 AS events in A. fumigatus for three different timepoints. 4 genes are DIS at multiple timepoints and may have an important regulatory function. Interestingly, we found 8 genes which are DIS but not DEG indicating that post-transcriptional regulation is independent from transcriptional regulation. Finally, we identified several genes that gain or lose functional domains during interaction with neutrophil when undergoing AS. We could show that AS is an important regulatory mechanism in fungi and is involved in infection processes in A. fumigatus. Further results can be used to gain new insights into the mechanism of AS, including multi-species comparison and examination of its influence on protein domains. [1] Grützmann K, Szafranski K, Pohl M, Voigt K, Petzold A, Schuster S (2014). Fungal Alternative Splicing is Associated with Multicellular Complexity and Virulence: A Genome-Wide Multi-Species Study. In DNA Research. 21 (pp. 27-39) [2] Perez-Nadales E, Nogueira MF, Baldin C, Castanheira S, El Ghalid M, Grund E, Lengeler K, Marchegiani E, Mehrotra PV, Moretti M, Naik V, Oses-Ruiz M, Oskarsson T, Schäfer K, Wasserstrom L, Brakhage AA, Gow NA, Kahmann R, Lebrun MH, Perez-Martin J, Di Pietro A, Talbot NJ, Toquin V, Walther A, Wendland J (2014). Fungal model systems and the elucidation of pathogenicity determinants. In Fungal Genetics and Biology. 70 (pp. 42-67)

Transcription factor – histones interplay in regulation of stress response and secondary metabolism Francesco Pezzini [1], Daniel Scharf [2], Axel Brakhage [1], Ekaterina Shelest [1] [1] Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute, Jena, Germany [2] University of Michigan, Ann Arbor, Michigan, USA

Transcription factors (TFs) fulfill their function binding to DNA. They often have to compete with nucleosomes, which occupy the TF binding sites (TFBSs) and prevent the binding. It has been shown that in S. cerevisiae the TFBSs of particular TFs can correlate or anti-correlate with nucleosome positions. However, this connection has not been investigated in filamentous fungi. Among many interesting features of the filamentous fungi is their known ability to produce secondary metabolites (SMs). Genes responsible for the biosynthesis of SMs are often organized in gene clusters. Usually these clusters are silent but can be activated under particular stress conditions. Epigenetic control plays an important role in regulation of SM gene clusters. However, it is not yet shown if nucleosome positioning is one of the factors that influence the expression of gene clusters, i.e., how important is the availability of TFBSs of those factors that can be involved in the cluster regulation. To address this problem, we considered gene expression in conjunction with nucleosome positioning and the occurrence of a particular TF binding motif, the CCAAT box. This motif is a well characterized binding pattern of CCAAT-binding complex (CBC), a TF that has a strong structural similarity to histones H2A and H2B. CBC is a known regulator of oxidative stress and iron metabolism; besides, CCAAT motif has been found in some SM clusters as well. To get insights into the mechanisms of CBC-nucleosome interplay, we constructed deletion mutants for one of Hap subunits, HapC. ΔHapC and wild type transcriptomes were compared to investigate the occupation of the CCAAT boxes by nucleosomes genome-wide and in direct Hap targets. Agent-based modeling of early Aspergillus fumigatus infection in mice Marco Blickensdorf, Sandra Timme, Marc-Thilo Figge Hans Knöll Institute, Jena, Germany

Aspergillus fumigatus is an airborne ubiquitous pathogen which is frequently inhaled every day. Once the conidia reach the lung, they are able to quickly adapt to the humid environment and, if not attacked by the immune system, can cause severe damage by germination and invasive

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TALKS - SYSTEMS BIOLOGY growth within hours, leading to mortality rates of up to 95%. Research on A. fumigatus often involves mice models for studies of the infection dynamics. However, relatively little is known about the effect of differences in lung morphology or infection dose with regard to naturally occurring infections in humans and experimental infections in mouse models. We implemented a spatio-temporal agent-based software framework to investigate the dynamics of early A. fumigatus infections in the human lung. It simulates a realistic morphological 3D environment of the human alveolus, the fungal conidia and phagocytes of the early immune response. We demonstrated the predictive power of computer simulations in previous studies [1, 2], while here we extend this model to alveoli of mice to compare differences due to various parameters and infection dynamics between humans and mice. For example, we simulate differences in the dose of infection or strength of the immune system and thereby gain insights to judge in how far results of experimental mice models can be transferred to human beings. [1] Pollmächer J, Figge MT (2014). Agent-Based Model of Human Alveoli Predicts Chemotactic Signaling by Epithelial Cells during Early Aspergillus fumigatus Infection. Sturtevant J, ed. PLoS ONE. 9(10):e111630. [2] Pollmächer J, Figge MT (2015). Deciphering chemokine properties by a hybrid agent-based model of Aspergillus fumigatus infection in human alveoli. Frontiers in Microbiology. 6:503.

Spatiotemporal analysis of synthetic microbial communities at the single-cell level in microfluidic interaction compartments Annika Rudat, Wolfgang Wiechert, Dietrich Kohlheyer, Alexander Grünberger Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH (Jülich Research Center), Jülich, Germany

Microbial communities represent one of the most fascinating complex systems in nature offering an unlimited diversity of biological processes, but are by far not understood. Deeper insights into the communication and interaction between multiple strains and species is thus mandatory for the development of novel mixed culture bioprocesses [1]. Therefore, novel analytical methods need to be developed to understand these processes in detail [2, 3]. In this contribution, we demonstrate the development and application of microfluidic cultivation chambers for microbial co-cultures. Two different strains can be cultivated in micrometer sized compartments which are connected by sieve structures with a sub-micron pore size, enabling the investigation of growth rates, interactions and cell-to-cell heterogeneity of two interacting microbial strains. As a proof of principle the behavior ofC. glutamicum ΔLysA, a lysine auxotroph strain, and its interaction to a Corynebacterium glutamicum lysine production strain was investigated. Our results show that the concept of single-cell co-cultivation has the potential to investigate bacterial interactions in more detail. This lays the foundation for an improved understanding of natural and synthetic co-cultures and could lead to novel strategies of designing and establishing microbial bioprocesses. [1] Peng, X., et al. (2016). Current Opinion in Biotechnology, 14:103-109. [2] Grünberger A, et al. (2014). Current Opinion in Biotechnology, 29: 15-23. [3] Grünberger A, et al. (2015). Cytometry A, 87(12): 1101-1115.

Discriminating fungal from bacterial infections by a consistent transcriptomics signature João Pedro Saraiva [1,2], Marcus Oswald [1,2], Antje Biering [1,2], Daniela Röll [1,2], Cora Assmann [3], Tilman Klassert [2], Markus Blaess [2], Kristin Czakai [4], Ralf Claus [2], Jürgen Löffler [4], Hortense Slevogt [3], Rainer König [1,2] [1] Network Modelling, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Beutenbergstraße 11a , Jena, Germany [2] Centre for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany [3] Septomics Research Centre, Jena University Hospital, Jena, Germany [4] University Hospital Würzburg, Würzburg, Germany

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Background: Systemic infections can lead to sepsis which is responsible for countless deaths worldwide. Amongst its causes, are infections by bacteria and fungi. Distinguishing fungal from bacterial pathogen-induced immune response is key to determine appropriate treatment. For this, in situ experiments have been performed to identify biomarkers. However, heterogeneity of the results due to different laboratory settings, pathogen strains, cell types and tissues, or the time of sample extraction etc. limit generalization of the results. Results: We focus on generating a transcriptomics gene signature capable of discriminating between fungal and bacterial infected samples independently of consistency-limiting factors such as those mentioned above. To this purpose, we employed Mixed Integer Linear Programming based classifiers on datasets of several leukocyte cultures comprised with fungal or bacterial pathogens. When combining the classifiers by a new joint optimization method [1], we increased biomarker consistency across the experimental setups, i.e. we increased the pairwise overlap (the number of prediction genes that overlap across experiments) by 43% when compared to a standard procedure. A refined gene list composed of 12 genes was consistent in expression (up- or down-regulated) across all analysed datasets. Testing our refined gene signature on an “unseen” dataset led to considerable 87% prediction accuracy. Conclusions: Identified genes were connected either directly or indirectly to the ERK-MAPK signalling, already shown to play important roles in the immune response to infection, and mTOR signalling and heme degradation. To note, cross-talk between these pathways has been demonstrated [2, 3]. Our developments show discriminating fungal and bacterial infection is feasible and robust across several datasets. Our consistent biomarker signature gives insight into the distinct immune response between fungal and bacterial infections. [1] Saraiva J et al. (2016). Integrating classifiers across datasets improves consistency of biomarker predictions for sepsis. in 6th IFAC Conference on Foundations of Systems Biology in Engineering. Elsevier ScienceDirect. [2] Mendoza MC et al. (2011). The Ras-ERK and PI3K-mTOR pathways: Cross-talk and compensation. Trends in Biochemical Sciences. 36. 320-328. [3] Morgan MJ et al. (2011). Crosstalk of reactive oxygen species and NF-kappa-B signaling. Cell Res. 21. 103-15.

Predictive Infection Modeling of Candida albicans Immune Escape in Human Blood Maria T. E. Prauße [1,2], Teresa Lehnert [1], Sandra Timme [1,2], Kerstin Hünniger [3], Oliver Kurzai [2,3], Marc T. Figge [1,2] [1] Applied Systems Biology, Leibniz-Institute for Natural Product Research and Infection Biology – Hans-KnöllInstitute, Jena, Germany [2] Friedrich-Schiller-Universität Jena, Jena, Germany [3] Fungal Septomics, Leibniz-Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute, Jena, Germany

Fundamental research in immunology is a well occupied scientific field, which nowadays connects both clinical findings and theoretical approaches. Immune reactions are such complex processes, that despite common effort many problems remain elusive for a long time. An example is the mechanism whereby fungal cells acquire resistance against phagocytosis and killing by immune cells which was detected in previously published whole-blood infection assays [1]. Unfortunately, such processes are difficult to investigate experimentally, because whole-blood is a complex system. Nevertheless, such problems need to be addressed, since fungal infections highly contribute to the increasing number of sepsis cases each year. A spontaneous resistance acquisition against phagocytosis and killing was implemented in the non-spatial state-based model (SBM) of wholeblood infections, originally created by Hünniger and Lehnert [1], which was then further developed by Lehnert and Timme [2]. We here study an alteration of the resistance acquisition mechanism, i.e. from a spontaneous mechanism to a type of process that is directly dependent on polymorphonuclear neutrophils (PMN). This is motivated by the fact that PMN are highly abundant in blood and are able to release effector molecules when triggered by fungal pathogens [1]. Since

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TALKS - SYSTEMS BIOLOGY we found that both types of resistance mechanisms fit the data from the whole-blood infection assays, neither of them could be rejected. Therefore, we investigated the model behavior under neutropenic conditions, i.e. for reduced counts of functional PMN in human blood. We were able to predict the possible effect of two resistance acquisition mechanisms in a whole-blood model infected with C. albicans cells. The SBM suggests that significant differences in the simulation results are due to the varied contribution by PMN under neutropenic conditions. In the future, the verification of this prediction may be investigated in laboratory experiments. [1] Hünniger K, Lehnert T, Bieber K, Martin R, Figge MT, Kurzai O (2014). A virtual infection model quantifies innate effector mechanisms and Candida albicans immune escape in human blood. PLoS Comput Biol 10(2), e1003479. [2] Lehnert T, Timme S, Pollmächer J, Hünniger K, Kurzai O, Figge MT (2015). Bottom-up modeling approach for the quantitative estimation of parameters in pathogen-host interactions. Frontiers in Microbiology 6(608).

Microbial camouflage by Candida albicans using human factor H - a numerical model Stefan Lang [1], Sebastian Germerodt [1], Christina Glock [1], Christine Skerka [2], Peter Zipfel [2], Stefan Schuster [1] [1] Dept. of Bioinformatics, Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, D-07743 Jena, Germany [2] Dept. of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany

Molecular mimicry is the formation of ’eclipsed’ molecules by parasites to avoid recognition and suppression by the immune system of the host. For example, several pathogenic Ascomycota and Zygomycota show such a behaviour, deceiving, in particular, the innate immune system. For example, Candida albicans binds human regulators like complement factor H and, thus, hides from the complement system. Such a camouflage can reach a point where the immune system can no longer clearly distinguish between self and non-self. This implies that a trade-off between attacking possible pathogens and own cells has to be made, which can in turn lead to autoimmunity. When studying mimicry by animals, is often modeled using methods of signal detection and game theory. Based on these methods, we here present a model of molecular mimicry by C. albicans involving human factor H. The main questions are to which extent microbes can deceive the host immune system and how the host can respond to enable a distinction between host cells and camouflaged microbes.

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Poster abstracts Environment The amoeba Protostelium fungivorum feeds on pathogenic yeasts and induces expression of virulence determinants Silvia Novohradská [1], Renáta Tóth [2], Sascha Brunke [3], Attila Gácser [2], Gernot Glöckner [4, 5], Jörg Linde [6], and Falk Hillmann [1] [1] Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Evolution of Microbial Interactions, Jena, Germany [2] Department of Microbiology, University of Szeged, Szeged, Hungary [3] Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Microbial Pathogenicity Mechanisms, Jena, Germany [4] Institute for Biochemistry, University of Cologne, Cologne, Germany [5] Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany [6] Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Systems Biology and Bioinformatics, Jena, Germany The prevalence of systemic mycoses caused by pathogenic yeasts is dramatically increasing. The leading causative agents are yeasts from the genera Candida and Cryptococcus. While some of them like C. albicans are already adapted to commensal lifestyle, other yeasts such as Cryptococcus, C. tropicalis or even C. parapsilosis have also been isolated from non-human sources and their virulence might have been shaped in part outside the human host as a strategy to counteract environmental predators. The selection pressure these impose could have led to the generation of survival strategies that contributed to the virulence potential when later confronted with immune cells. To test this hypothesis, we have isolated and sequenced a novel species of professional mycophagous amoeba, Protostelium fungivorum, a genus widely spread in nature. Feeding experiments revealed a broad prey spectrum within the fungal kingdom, including yeasts, as well as some filamentous fungi. Rhodotorula mucilaginosa and C. parapsilosis served as the preferred food sources, being ingested, processed via phagolysosomes, and killed within less than 10 min. Although the efficiency of amoeba killing exceeded 99%, a slight fraction of cells showed the ability to survive the predation via reversible transition into hyphae, which allowed the escape from killing and secured the survival of a stable subpopulation. As killing and digestion were most effective with C. parapsilosis, we used this pathogen in a dual-transcriptome approach to identify the targets of predatory-prey interactions. Interestingly,

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amoeba responsive genes included those involved in the intracellular mobilization of metal resources, response to oxidative stress, filamentous growth and some hydrolytic enzyme. The most promising targets have been already disrupted and their phenotypes will reveal if traits that have originated to counteract with soil predators could also have supported resistance against innate immune cells. Mechanisms of survival of Enterococcus mundtii in the intestinal tract of Spodoptera littoralis Beng Soon Teh, Tilottama Mazumdar, Wilhelm Boland Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany Microbial symbionts are known to live in close associations with animals, plants, and insects. Insects harbor the beneficial microbes, which provide the host with essential nutrients, aid in food digestion, and protection against pathogens. The cotton leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae) is one of the most successful polyphagous insect pests that causes crop losses in agricultural industry. The gut microbial communities of Spodoptera are well characterized, and the insect is a popular model organism in studying the insectmicrobe and microbe-microbe interactions. It is known that the gut of S. littoralis is predominated by Enterococcus mundtii in the larvae, pupae, and adults [1]. In this study, E. mundtii was selected as a model bacterium because of its unique symbiotic relationship with the host insect. In addition, using stable isotope labeling-based approach, E. mundtii has been shown to be highly metabolically active inside the intestinal tract of S. littoralis [2]. Until now, the mechanisms of Enterococcus survival in the gut environment are unknown. To gain better understanding of the survival strategies, we have constructed the GFP-tagged bacteria to track its colonization in the intestine across different stages of development. We showed that the fluorescent bacteria survived and proliferated in the intestinal tract of the insect of all life stages for up to second generation offspring following ingestion. Based on this interesting discovery, we further explore the underlying factors that drive the insect-microbe interactions by analyzing the transcriptome of bacterial and insect gut epithelial cells through RNAseq. To do that, fluorescence-activated cell sorting (FACS) was used to recover the GFP bacterial cells from the respective gut tissues. We expect that the transcriptome data will significantly expand our understanding of the functional roles of indigenous bacteria towards the development of the insect. [1] Chen, B., Teh, B. S., Sun, C., Hu, S., Lu, X., Boland, W., Shao,

POSTERS - ENVIRONMENT Y. (2016). Biodiversity and Activity of the Gut Microbiota across the Life History of the Insect Herbivore Spodoptera littoralis . Sci Rep, 6 , 29505. doi: 10.1038/srep29505 [2] Shao, Y., Arias-Cordero, E., Guo, H., Bartram, S., Boland, W. (2014). In vivo Pyro-SIP assessing active gut microbiota of the cotton leafworm, Spodoptera littoralis . PLoS One, 9 (1), e85948. doi: 10.1371/journal.pone.0085948

Characterization of drug resistance pattern of bacterial isolates recovered from a bovine abattoir wastewater in Akure, Nigeria Olubukola Olusola-Makinde [1,2], Fatusa Adetuyi [1], Daniel Arotupin, Anthony Okoh [2] [1] Federal University of Technology, Akure, Nigeria [2] University of Fort Hare, Alice, South Africa The heavy usage of antibiotics in animal husbandry, problems of transfer of resistance genes between pathogenic and non-pathogenic organisms, and increasing discharge of untreated abattoir wastewater into community streams in Akure, Nigeria called for this study on the abundance of multi-drug resistant bacteria in the abattoir wastewater. Bacteria were isolated using standard spread plate method. The antibiotic susceptibility pattern was determined using the standard disc diffusion method and a panel of 14 conventional antibiotics including pefloxacin (30 μg), oflaxin (10 μg), streptomycin (30 μg), septrin (30 μg), chloramphenicol (30 μg), sparfloxacin (10 μg), ciprofloxacin (10 μg), amoxicillin (30 μg), augmentin (30 μg), gentamycin (10 μg), erythromycin (15 μg), ampiclox (30 μg), zinnacef (25 μg) and rocephin (25 μg). Identification of selected multiple antibiotic resistant isolates was done by 16S rRNA gene sequencing. Out of the 41 Gram positive bacteria and 75 Gram negative bacteria isolated, 95.12% and 41.33% respectively displayed multiple drug resistance. Estimated multiple antibiotic - resistant indices (MARI) ranged from 0.3 to 0.9. Surprisingly, all the Grampositive isolates and 45.3% of the Gram negative isolates were resistant to β-lactamase group of antibiotics. 70% of Gram positive isolates were susceptible against ciprofloxacin (10 μg) while 90% of the Gram negative isolates were susceptible to gentamycin (10 μg). Comparison with related sequences in database identified the selected multiple antibiotic resistant isolates to be Alcaligenes faecalis, Alcaligenes faecalis subsp. faecalis, Bacillus cereus and Lysinibacillus macrolides. We conclude that abattoir wastewaters are reservoirs for the dissemination of multi-drug resistant bacteria which are of public health importance. The Merit of Expression Noise Depends on the Environment Anja Lück [1], Lukas Klimmasch [2], Sebastian Ger-

merodt [1], Christoph Kaleta [3] [1] Department of Bioinformatics, Friedrich Schiller University Jena, Germany [2] Bio Systems Analysis Group, Institute of Computer Science, Friedrich Schiller University Jena, Germany [3] Research Group Medical Systems Biology, Institute for Experimental Medicine, Christian-AlbrechtsUniversity Kiel, Germany Singe-cell organisms face a multitude of potential environments differing in hospitality and timescale. This variance in environmental conditions leads to a fundamental problem: How to allocate resources effectively in any environment, so that growth rate and adaptation to changes in the environment are optimally balanced? One of their survival mechanisms is to adjust the degree of noise inherent in gene expression. We applied an evolutionary algorithm to a simple agent-based model of bacterial metabolism to investigate the impact different food environments have on the inhabiting organisms’ metabolic and genetic adaptations. Our model permits qualitative conclusions concerning the magnitude of expression noise regarding the demands of the respective environments, independent of its origin. We found that in a constant food environment, expression noise is kept as low as possible and that its merit in an alternating food environment depends on the environment’s total nutritional richness. Above a threshold nutrient concentration, we can observe behaviour that resembles stochastic switching. Our framework permits qualitative conclusions concerning the magnitude of noise concerning the demands of the environment, independent of its molecular origin and it provides a starting point for further investigation of the environment-noise interaction in microbes. Targeted gene replacement in two Streptomyces strains Hanka Brangsch, Erika Kothe Friedrich Schiller University, Institute of Microbiology, Microbial Communication, Germany Site-directed deletion of a gene of interest in vivo offers the opportunity to study the influence of this gene on different phenotypic traits of a bacterial strain and its performance under different growth conditions. This can give valuable information on the gene’s importance for the survival in the environment. In the present study, a targeted gene replacement procedure was chosen for site-directed mutagenesis. For this approach the gene is firstly replaced on a cosmid by a cassette containing a selectable marker which is then used for transformation of the wild type strains. In the resulting transformants the native gene is exchanged with

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the resistance cassette by homologous recombination. Here, this approach is used to validate the involvement of candidate genes in the heavy metal resistome of the two Streptomyces strains S. mirabilis P16 B-1 and S. acidiscabies E13. These strains have been isolated from a highly contaminated site (Ronneburg, Germany) and show especially high resistances, e.g. against nickel. As fist target sodN was chosen, the gene coding for a nickel-containing superoxide dismutase (NiSOD), which is important for controlling oxidative stress induced by heavy metals. The sodN deletion mutants are tested for their heavy metal resistance, in order to confirm the importance of this gene for the survival under heavy metal stress. Effect of antibiotics in the environment: disturbances of plant-bacterial endophyte interactions in soft rush, Juncus effusus, after repeated exposure to sulfamethoxazole and trimethoprim Muhammad Arslan [1], Marcello Santoni [1,2], Arndt Wiessner [1], Thomas Neu [3], Jochen A. Müller [1] [1] Helmholtz Centre for Environmental Research UFZ, Environmental Biotechnology, Leipzig, Germany [2] Sapienza - Università di Roma, Dipartimento di Chimica, Rome, Italy [3] Helmholtz Centre for Environmental Research UFZ, Department of River Ecology, Magdeburg, Germany Organic micropollutants such as antibiotics are recent ecotoxicological challenges for various environmental systems including their associated human societies. Most previous studies reported on the effects of such compounds on model organisms; comparatively little is known about their impact on plants and in particular the important endophytic community. The present study aims to elucidate disturbances of plant-endophytes interactions as a post-stress event after exposures to the antibiotics sulfamethoxazole (SMX) and trimethoprim (TMP). Soft rush (Juncus effusus), a common wetland plant, was repeatedly exposed to low aqueous concentrations of SMX and TMP. Plant status was evaluated based on evapotranspiration rates and by visual inspection. Changes of endophytic communities in roots and shoots of exposed and unexposed plants were tracked via culture-dependent (MPN, isolation of bacterial strains) and culture-independent (qPCR, FISH) approaches. During exposure to SMX and TMP, evapotranspiration of plants decreased. Evapotranspiration recovered in the absence of the antibiotics, albeit to lower values than prior exposure. After several exposures plants became infested with insects, evapotranspiration was almost zero, and plant tissue turned necrotic. The comparative analyses of endophytic communities

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showed that roots of post-exposed plants had statistically significant increases of Gammaproteobacteria, Firmicutes, and Actinobacteria. Some of the isolated strains are related to previously described phytopathogens. Endophytic fungi were not observed in this study. Shoots harbored lower endophyte abundances than roots, and there was no statistical difference between exposed and unexposed plants. While the direct cause for the decline in plant status after exposure to SMX and TMP is yet uncertain, it appears that it was due to a lasting dysbiosis of the endophytic community in the roots, triggered by treatment with the antibiotics. Studying the mechanism of environmental perception in the unicellular green alga Chlamydomonas reinhardtii Prasad Aiyar, Daniel Schaeme, Hannes Dathe, Severin Sasso and Maria Mittag Institute for General Botany and Plant Physiology, Friedrich Schiller University of Jena, Germany Calcium ions are important intracellular secondary messengers often used by eukaryotic cells to respond to changes in their external environment. Microalgae are an essential part of the food chain as they contribute significantly to the global carbon fixation [1]. To get a better understanding about this process, it is important to understand how microalgae respond to changes in environmental conditions. Earlier work on the marine diatom, Phaeodactylum tricornutum showed how this microalga responds to external signals such as temperature, osmotic stress and iron by altering its calcium homeostasis [2]. However, very limited information is available on impact of such changes on freshwater microalgae. Using the freshwater model microalgae Chlamydomonas reinhardtii, we have established a protein based reporter line for measuring cytosolic calcium ion concentration. Using this reporter line we study how various environmental factors influence the cytosolic Ca2+ concentration in C. reinhardtii. scriptsize [1] Field, C.B., M.J. Behrenfeld, J.T. Randerson and P. Falkowski. 1998. Science 281:237-240. [2] Falciatore, A., d’Alcalà, M. R., Croot, P., & Bowler, C. 2000. Science 288: 2363-2366. Investigation of microbial community in extreme saline environments Madlen Franze, Andrea Cherkouk Helmholtz-Zentrum Dresden – Rossendorf, Institute of Resource Ecology In Germany, three kinds of potential host rock systems (clay, crystalline and rock salt) are considered for the long-term storage of highly radioactive waste in a deep geological repository. In this study

POSTERS - ENVIRONMENT the focus is on the habitat rock salt to get a more detailed understanding of the way of life of the microorganisms occurring there. Next to bacteria and fungi, extreme halophilic archaea are dominating this habitat. It is of interest to know what kind of microorganisms are living there, how active they are under repository relevant conditions and how these microorganisms can influence the safe storage of the waste. The microbial diversity of two different types of samples (rock salt from Germany & saline soil sample from Israel) was investigated with a combination of culturedependent and -independent methods. From the two samples DNA was extracted, purified for PCR amplifications of 16S rRNA genes and finally sequenced with Illumina MiSeq by RTL Genomics. Additionally, a specific portion of each sample was incubated in three different sodium chloride concentrations of modified R2A resuscitation buffer and subsequently spread on corresponding agar plates (37 ◦ C) to get isolates which were further characterized. Different halophilic microorganisms could be isolated from both kinds of samples. The isolates from rock salt can all be assigned to different Halobacterium species. Whereas from the saline soil samples different archaeal genera such as Natrinema, Halorubrum as well as Halobacterium could be isolated. Bacterial isolates were related to different Bacilli such as Halobacillus and Aquibacillus species. The obtained isolates can be further used for investigations e.g. regarding their activity under repository relevant conditions. The role of oxidative stress in the antifungal drug response of A. fumigatus Elena Shekhova, Olaf Kniemeyer, Axel A. Brakhage Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Jena, Germany Drug resistance of the fungal pathogen A. fumigatus represents an increasing clinical problem worldwide. Significant numbers of A. fumigatus isolates from patients show resistance to currently available antifungal compounds such as azoles. Our aim is to understand the link between the cellular redox environment and the susceptibility of the fungus to antifungal agents. Initially, we identified that three different antifungal substances itraconazole, terbinafine, and amphotericin B, have an impact on fungal redox homeostasis by causing severe intracellular oxidative stress. One hypothesis says that these antifungals may have an effect on fungal mitochondria by causing an increased ROS induction via respiratory complex I. Accordingly, we detected an elevated level of ROS during cultivation of A. fumigatus in the pres-

ence of itraconazole, terbinafine or amphotericin B by staining with the oxidant sensing probe 2’,7’dichlorodihydrofluorescein diacetate. The elevated ROS levels induced by antifungals were abolished by inhibition of complex I with rotenone. In line with that, evaluation of lipid peroxidation by the TBARS assay revealed that rotenone pretreatment decreased ROS-induced lipid peroxidation during incubation of A. fumigatus with antifungals. Interestingly, after complex I inhibition the expression level of the ergosterol biosynthetic gene erg11A (CYP51) did not change in antifungal drug-treated A. fumigatus cells. Taking all together, our study suggests that the induction of ROS production contributes to the ability of antifungal compounds to inhibit fungal growth. Moreover, mitochondrial complex I is obviously the main source of deleterious ROS production after antifungal drug treatment. The fact that fungal pathogens can modify their drug response and consequently can adapt to this environmental challenge, for example by changing complex I activity, will be a subject for further investigations. Response of ectomycorrhizal partners to metal stress Manuela Östreicher, Katrin Krause, Erika Kothe Microbial Communication, Friedrich Schiller University Jena, Germany Ectomycorrhizal symbiosis is known for an intensive nutrient and signal exchange between plants and fungi. In addition, fungi protect the plant from pathogens, drought, metal and oxidative stresses. Here, the response to various metal species was examined in an axenic co-culture using the ectomycorrhiza interaction of the basidiomycete Tricholoma vaccinum and spruce (Picea abies). The concentration gradients chosen for each of the metals Al, Cd, Cs, Cu, Fe, Mn, Ni and Zn revealed the tolerance ranges for fungus and plant, respectively. Basis for the assessment were multiple parameters regarding e.g. fungal growth, aerial mycelium formation or pigment production as well as plant biomass, habitus, development or health. The study delivered insight into the practicability and sensitivity of the parameters used, and will provide the basis for gene expression studies. Establishing a model system for studying interactions of flagellate green microalgae in the marine environment David Carrasco, Severin Sasso, Maria Mittag Institute of General Botany and Plant Physiology, Friedrich Schiller University, Jena, Germany The flagellated freshwater alga Chlamydomonas reinhardtii has been used for decades as a model

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organism to study different biological processes, such as photosynthesis, flagellar function or light responses [1]. In the marine environment, the use of model organisms is also starting to emerge [2]. For example, the red microalga Cyanidioschyzon merolae, the diatom Phaeodactylum tricornutum or the green non-flagellated Ostreococcus tauri are being extensively studied. Here we aim to establish a model system for a marine flagellated green microalga. We examined the properties of two isolates of the flagellated green microalga Chlamydomonas, which were isolated from different marine environments. These are C. euryale (CCMP 219) and C. sp. (SAG 25.89), which are closely related according to the phylogenetic analysis of the 18S rRNA. The growth conditions for both species have been characterized. Both strains grow in the same pH range of pH 5 to pH 9, but show different salinity preferences. C. sp represents a typical marine strain, preferring salinities between 0 - 30 g/L, while C. euryale shows the most growth in low salinities, but displays halotolerance in brackish waters up to 30 g/L. [1] Merchant, S. S. et al. The Chlamydomonas genome reveals the evolution of key animal and plant functions. Science 318, 245-50 (2007). [2] Cock, J. M. & Coelho, S. M. Algal models in plant biology. Journal of Experimental Botany 62, 2425-2430 (2011).

Influence of soil-bacteria on the phytoremediation-potential of different tree species on the testing-site Gessenwiese David Fürst [1], Sebastian Pietschmann [1], Daniel Mirgorodsky [2], Dirk Merten [2], Georg Büchel [2], Erika Kothe [1] [1] Institute of Microbiology, Friedrich Schiller University, Jena, Germany [2] Institute of Geosciences, Friedrich Schiller University, Jena, Germany A better understanding of the interactions between plants, microorganisms and soil is essential for the optimal utilization of plants for the remediation of heavy-metal contaminated soils. The former uranium leaching heap Gessenhalde near Ronneburg in eastern Thuringia provides an ideal environment for the investigations of these interactions. The testsite Gessenwiese was set up specifically to compare the effects of different microbial inoculations and soil amendments (addition of 5% and 20% rendzina soil) on the phytoremediation-potential of different tree-species. In 2016 three tree-species (Betula pendula, Alnus incana, Salix triandra x viminalis „Inger") were planted and inoculated. Microbial amendments consisted of Streptomyces mirabilis P16B-1 and the arbuscular mycorrhizal fungus Rhizophagus irregularis. To determine the influence of the different treatments, microbial inoculations as well

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as soil amendments, the tree heights and trunk diameters were measured. Furthermore plant biomass was harvested and leaves measured for metal concentrations. Soil samples were extracted for bioavailable metal loads, and from both the bioconcentration factors could be calculated. The soil samples showed varying distribution of Al, Cd, Cu, Mn, Ni, and Zn between plots as well as heterogeneities within plots. Ectomycorrhizal fungi reduce metal toxicity of birch trees growing on a former uranium mining site as revealed by micro-PIXE analysis Arno Märten [1], Steffi Formann [2], Mitja Kelemen [3], Primož Vavpetiˇc [3], Primož Pelicon [3], Katarina Vogel-Mikuš [3,4] [1] Institute of Geosciences, Friedrich Schiller University Jena, Burgweg 11, D-07749 Jena (Germany); *Email: [email protected] [2] Institute of Microbiology, Friedrich Schiller University Jena, Neugasse 25, D-07743 Jena (Germany) [3] Jožef Stefan Institute, Jamova 39, SI-1000, Ljubljana (Slovenia) [4] Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia) The majority of terrestrial plants live in symbiosis with mycorrhizal fungi. A special form of mycorrhiza is the ectomycorrhiza (ECM) which means the mutualistic relationship of a host tree with a fungal partner. Thereby the tree delivers carbon e.g. sugars to the fungus and can benefit from enhanced nutrient and water uptake by the fungal hyphae in return. Furthermore, some of the ECM fungi can improve the resistance of their host trees to metal ion toxicity. During the ECM infection of the host tree, special organs called short roots are formed, that function as interface between the tree roots and the fungi. In our study short roots of birch trees growing on substrate of an abandoned uranium mining site were analyzed for their metal distribution. These mining influenced sites are in many cases affected by severe environmental degradation. For the analyses of the mycorrhizal roots a nuclear microprobe (micro-PIXE) was used, that allows elemental mapping of biological samples with a minimum resolution of about 1 μm and detection limits in the lower ppm-range. Three different ECM species were identified as mycobionts: Meliniomyces bicolor, Pisolithu tinctorius, and Cenococcum geophilum . The analyses reveal that metals like Al, which was the main potentially phytotoxic contaminant of the study area, as well as Ti and Fe were mainly concentrated in the hyphal mantle. This compartment around the short roots works that is formed by the fungus is the interface and contact area between the soil and the rhizosphere.

POSTERS - PATHOGENESIS In contrast Cu, pollutant and phytotoxic element likewise Al, had the highest levels in the woody tissue (central cylinder) of the short roots. These findings show, that all three ECM fungi serve as barrier-like protection of the birch vegetation from possibly toxic metal concentrations with exception of Cu. Heavy metal tolerance mechanisms in Streptomyces Thomas Krauße [1], Benjamin Funai [1], Karin Martin [2], Florian Kloß [2], Nico Jehmlich [3], Boyke Bunk [4], Jörg Overmann [4], Erika Kothe [1] [1] Institute of Microbiology, Friedrich-SchillerUniversity Jena, Germany, [2] Leibnitz-Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena, Germany [3] Helmholtz-Centre for Environmental Research UFZ, Leipzig, Germany [4] Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany As a result of mining activities, metal polluted areas with excessive acidification are found worldwide. Near Ronneburg, eastern Thuringia, engineered remediation of uranium mining remnants with contaminated former heap sites and groundwater are found after conservative remediation techniques. To improve future land-use, we investigated microbially assisted phytoremediation. Two indigenous Streptomyces strains isolated from the area were characterized for their potential in bioremediation. The two heavy metal resistant strains Streptomyces mirabilis P16B-1 and Streptomyces acidiscabies E13 have genomes of 8.9 Mb (with a 530 kb plasmid) coding for about 8,600 genes and 9 Mb (and a plasmid of 111 kb) with about 8,000 genes, respectively, were investigated. Approximately two thirds of the genes could be functionally annotated. Based on these information, a large number of metal-related genes were identified which we are now investigating for underlying molecular mechanisms. A signaling pathway was found for the thiostrepton inducible promotor (tipA), that is induced under metal stress and through signal compounds, especially with thiopeptide antibiotics under sub-inhibitory concentrations. To identify target pathways, proteome and metabolome analyses were performed. Monitoring transcriptional changes are addressed by RNAseq from soil microcosms. With his work we want to elucidate mechanisms for metal tolerance with potential for an application in microbially assisted phytoremediation. Identification of microorganisms mobilizing radionuclides from black slate

Marie Harpke [1], Katja Burow [1,2], Erika Kothe [1], Georg Büchel [2] [1] Institute of Microbiology, Microbial Communication, Friedrich Schiller University Jena, Germany [2] Institute of Geosciences, Applied Geology, Friedrich Schiller University Jena, Germany The microbial community in the subsurface depends on the mineral and element composition of bedrock, the (physico)chemical properties of groundwater and the (im)mobilization processes. The importance of microorganisms to determine these conditions have long been underestimated. Elements like the radionuclides U, Th and Ra can be released to the water phase by rockmicroorganism interactions including auto- and heterotrophic leaching, or mobile fractions may be reduced by biosorption. The characterization of microorganisms mobilizing radionuclides from black slate was based on isolates obtained from seepage water, biofilms and black slate samples from the former alum mine ’Morassina’. Identification by 16S rDNA/ITS sequencing resulted in e.g. Mucor sp. (MF 83) and Verticillium sp. (MF 93), which were shown to form siderophores in contrast to the bacterial isolates e.g. Arthrobacter sp. (MB 110) and yeasts isolates . The metal complexation and resulting mobilization of radionuclides corresponding to siderophore production is studied by identification of siderophores produced by the fungal isolates via ESI-MS. In addition, the rock-microorganism interactions were investigated. Fluorescence microscopy indicated that Mucor sp. (MF 83) and Arthrobacter sp. (MB 110) interact directly with the black slate. SEM studies as well as laser ablation ICP-MS are used to verify the contact and mobilization processes from black slate. The uptake and transport of radionuclides through hyphal compartments are specifically addressed.

Pathogenesis An Audit of Dengue Fever Cases in the Year 2013 at Civil Hospital Karachi-Pakistan Asma Bashir Shaheed Zulfikar Ali Bhutto Institute of Science and Technology, Karachi, Pakistan Background: Dengue virus is endemic in Pakistan, and occurs throughout the year, but with often with peaks in certain seasons. Dengue virus remains a major cause of morbidity and mortality; there is scarcity of data looking at the overall trend of dengue infection in Pakistan. Despite this, nearly 700 cases of confirmed dengue fever have been reported across Pakistan this year and many of the reported cases have been in Karachi; how-

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ever dengue fever is also increasing in other parts of Sindh. Methods: Patients suffering from high grade fever visiting Medical and Paediatrics outpatient departments as well as indoor patients of Civil Hospital, Karachi, Pakistan, in the year 2010 (from Jan.to Dec.) were included in this study. Patients were initially screened for platelet count and test for Dengue fever. Blood was collected aseptically and CBC (Platelet count) was done on Sysmex Haematology autoanalyser and test for Dengue antibodies IgM and IgG was done by Rapid Immunochromatography and ELISA technique. Dengue Antigen test was also done on some patients. Results: Total 2321 patients were screened for Dengue fever, out of these 585 were reported positive for Dengue fever i-e 25.2%. 384 were males while 201 were females. Dengue Antibodies IgM and IgG (ICT) was done on 1118 samples, 585 were positive for IgM alone or both for IgM and IgG. i-e 26.39% Dengue Antibodies IgM and IgG (ELISA) was done on 260 samples 87 were positive for IgM (33%) and 28 were positive for IgG alone (10.77%). However, Dengue Antigen was done on 943 samples, 175 samples were reported positive for Dengue Antigen (18.5%).The result analysis indicated that the age group most affected was 20-40 years. Male /female ratio was found 2:1.Besides this,90% patients had low platelet count i-e less than 100,000/cumm, 10% had normal or near normal platelet count most of them showed decrease in platelet count later on. Conclusion: In this current study, we concluded that from Jan 2011 to August 2011 the cases were sporadic but from September, there was sudden increase in the number of case which lasted till end of the year. According to the results, ICT is a reliable and rapid technique; the results are available in 15 minutes. ELISA technique though more reliable but time consuming. Due to the need for early diagnosis of Dengue fever Dengue Antigen test which is positive on the first day of fever, but the problem was that as soon as antibodies appear the antigen is cleared from the blood stream. The effect of Candidalysin on bacteria Toni Förster, Selene Mogavero, Bernhard Hube Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute Jena (HKI), Jena, Germany The opportunistic pathogen Candida albicans is a common and mostly harmless inhabitant of human mucosal surfaces. Only under predisposing conditions like immunosuppression or antibiotic treatment, C. albicans can switch to a pathogenic state. It is therefore likely that interactions with other members of the human microbiota contribute to its

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commensal state. The recently discovered peptidetoxin Candidalysin is an important virulence factor of C. albicans . Here we want to investigate whether Candidalysin is also active against bacteria of the human microbiota. We screened a total of 35 human associated bacteria for growth defects in the presence of synthetic Candidalysin and found that the toxin inhibits the growth of distinct bacteria. This effect was analyzed in more detail by measuring minimal bactericidal concentrations (MBC), membrane permeabilization or metabolic activity. Moreover, we have hints that Candidalysin, which is not totally soluble and forms aggregates in aqueous solution, co-aggregates also with bacteria leading to the formation of large peptide-bacteria clumps. We additionally tested derivatives of Candidalysin for antimicrobial activity and found that an N-terminal truncation of Candidalysin considerably improves its antimicrobial activity. These truncated versions are more toxic and are active against more bacterial species than the original Candidalysin. In conclusion, we showed that Candidalysin is active against selected bacteria and modified versions of the peptide may even have increased activity. The peroxiredoxin Asp f3 protects A. fumigatus against external superoxide Jana Boysen [1], Bettina Bardl [2], Falk Hillmann [1] [1] Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Evolution of Microbial Interactions, Jena, Germany [2] Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Bio Pilot Plant, Germany The ubiquitous mould Aspergillus fumigatus is a filamentous ascomycete with a generally saprophytic lifestyle that is also known to be an opportunistic human pathogen. Especially immunocompromised patients are at a high risk to suffer from A. fumigatus infections which range from allergic reactions to often fatal invasive aspergillosis (IA). Chronic granulomatous disease results in a severe immunodeficiency based on the reduced capability to produce reactive oxygen species (ROS), and patients are at an extremely high risk to develop IA. However, it is up to now not known, how reactive oxygen species formation protects against fungal infections and whether these molecules target the fungus directly. We have recently characterized the major allergen Asp f3 of A. fumigatus. Structural and functional studies identified Asp f3 as a two-cysteine type peroxiredoxin which showed moderate thioredoxin dependant peroxidase activity in vitro . Nevertheless, deletion of the asp f3 gene led to a drastic increase in the sensitivity

POSTERS - PATHOGENESIS to ROS and the mutant was avirulent in a mouse model of pulmonary aspergillosis. Since the protective mechanism of Asp f3 during host invasive growth and in the presence of ROS is unknown, we aim to elucidate its cellular function as well as the biochemical targets of ROS. To monitor their effects on A. fumigatus , we have established an in vivo assay, which allows specific exposure to external pulses of superoxide (O2 - ), the primary product of the NADPH oxidase of innate immune cells. Surprisingly, sensitivity of the mutant towards O2 was specific and comparably higher than to hydrogen peroxide (H2 O2 ), indicating that O2 - causes direct damage on at least one yet unknown cellular target. Neither O2 - nor H2 O2 exposure alone was lethal to A. fumigatus, as conidia and germlings could recover growth after periods of regeneration, suggesting that Asp f3 function is rather related to the repair of oxidative damage than to the direct reduction of toxic ROS. A taxonomic revision of the mucormycosis causing Mucor circinelloides complex Lysett Wagner [1], Volker Schwartze [2,3], Kerstin Voigt [2,3], Sybren de Hoog [4], Oliver Kurzai [1], Grit Walther [1] [1] German National Reference Center for Invasive Mycoses, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany [2] Jena Microbial Resource Collection, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany [3] Faculty of Biology and Pharmacy, Institute of Microbiology, Department Microbiology and Molecular Biology, Friedrich Schiller University Jena, Jena, Germany [4] CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands Mucor circinelloides is one of the main agents of mucormycosis, a rare but emerging infection caused by members of the Mucorales with often dramatic course and high mortality rates. Generally, only patients with severe immune or metabolic impairments are affected. Mucormycoses are difficult to treat because of their intrinsic resistance against first line antifungals such as voriconazole. In the genus Mucor also strains with elevated minimum inhibitory concentrations for other azoles have been reported. The last taxonomic revision of Mucor circinelloides and its relatives dates from 1976 and was based on morphology and mating behavior only. Molecular sequence analyses based on ITS and LSU sequences revealed a higher diversity within this species complex and the restriction of clinical specimens to certain clades. The aim of this study was to establish a new species con-

cept of the Mucor circinelloides complex based on a multilocus phylogeny, mating tests, antifungal susceptibility testing as well as morphological studies. Applying genealogical concordance phylogenetic species recognition the analysis of four commonly used phylogenetic markers (ITS, mcm7, rpb1, tsr1) and the newly established marker cfs putatively encoding a cyclopropane fatty acylphospholipid synthase recognized 16 phylogenetic species within the Mucor circinelloides complex. Fourteen out of the 16 phylogenetic species were finally accepted as discrete species because they could be characterized by distinct phenotypic traits. Four of these species have not been described yet. Clinically relevant species of the Mucor circinelloides complex are M. circinelloides, M. velutinosus, M. janssenii, M. lusitanicus and M. ramosissimus with the most cases caused by the first two species. Antifungal susceptibility profiles of the clinically relevant species differ against azoles. This revised taxonomic concept of the Mucor circinelloides complex allows a correct diagnosis connected with the reliable assignment of antifungal susceptibility data which is crucial for a successful treatment. Proteomic studies on the degradation of DHN melanin, a fungal virulence factor Annica Pschibul, Thomas Krüger, Olaf Kniemeyer, Axel A. Brakhage Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Department of Molecular and Applied Microbiology, Jena and Institute of Microbiology, Friedrich Schiller University, Jena Fungal melanins have a wide range of roles in fungal pathogenicity. For example, the layer of dihydroxy-naphthalene (DHN) melanin located on the outside of spores of the mould Aspergillus fumigatus has been reported to be involved in masking immunogenic structures on the spore surface [1]. It has also been shown to reduce phagolysosomal acidification [2] and to inhibit apoptosis of macrophages after phagocytosis of the spores [3]. In addition, it contributes to the quenching of reactive oxygen species, which host immune cells produce as a defence mechanism [4]. The biosynthesis of DHN melanin has been studied in detail and enzymes involved in each step of the process have been elucidated. The only exception from this is the final step of biosynthesis, the polymerisation of 1,8-DHN to DHN melanin. In contrast, nothing is known about the degradation of DHN melanin. In this study, a proteomics approach was employed in order to identify enzymes with a possible role in DHN melanin degradation. For this purpose, the proteome of A. fumigatus grown in the presence of 1,8-DHN of was analysed. Both 2D gel electrophoresis and gel-free liquid chromatography-

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mass spectrometry (LC-MS/MS) were employed. A comparison of the proteins formed in the presence of 1,8-DHN and a control showed a specific response to the stress created by the presence of 1,8-DHN. Significantly enriched categories of differentially expressed proteins according to GO ontology were, for example, oxidoreductase activity, nucleotide binding, transferase activity, ATP binding and catalytic activity. Some of these enzymes may be involved in DHN melanin degradation. These are for example oxygenases, which could assist in initial steps of the degradation process. Further studies are planned in order to elucidate the role of these enzymes and to obtain more information on the degradation process of DHN melanin. [1] Bayry, J., Beaussart, A., Dufrene, Y. F., Sharma, M., Bansal, K., Kniemeyer, O., . . . Beauvais, A. (2014). Surface Structure Characterization of Aspergillus fumigatus Conidia Mutated in the Melanin Synthesis Pathway and Their Human Cellular Immune Response. Infection and Immunity, 82 (8), 3141-3153. doi:10.1128/iai.0172614 [2] Thywißen, A., Heinekamp, T., Dahse, H., Schmaler-Ripcke, J., Nietzsche, S., Zipfel, P. F., and Brakhage, A. A. (2011). Conidial Dihydroxynaphthalene Melanin of the Human Pathogenic Fungus Aspergillus fumigatus Interferes with the Host Endocytosis Pathway. Frontiers in Microbiology, 2 . doi:10.3389/fmicb.2011.00096 [3] Volling, K., Thywissen, A., Brakhage, A. A., and Saluz, H. P. (2011). Phagocytosis of melanized Aspergillus conidia by macrophages exerts cytoprotective effects by sustained PI3K/Akt signalling. Cellular Microbiology, 13(8), 1130-1148. doi:10.1111/j.14625822.2011.01605.x [4] Langfelder, K., Streibel, M., Jahn, B., Haase, G., and Brakhage, A. A. (2003). Biosynthesis of fungal melanins and their importance for human pathogenic fungi. Fungal Genetics and Biology, 38(2), 143-158. doi:10.1016/s1087-1845(02)00526-1

Regulatory mechanisms of staphylococcal persistence Anke Siegmund [1,3], Fabio Gratani [2], Christiane Wolz [2], Silke Niemann [3], Bettina Löffler [1,4], Lorena Tuchscherr [1,4] [1] Institute of Medical Microbiology, Jena University Hospital, Jena, Germany [2] Department of Medical Microbiology and Hygiene, Interfaculty Institute for Microbiology and Infection Medicine Tübingen, Tübingen, Germany [3] Institute of Medical Microbiology, University Hospital of Münster, Münster, Germany [4] Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany Staphylococcus aureus is a frequent pathogen that causes chronic and therapy-refractory infections such as osteomyelitis [1, 2]. S. aureus can act as a facultative intracellular pathogen capable of invading multiple types of host cells and persist in the intracellular environment for long-time periods that is associated with phenotype switching to small

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colony variants (SCVs). Yet, the signals, stress factors and mechanisms that induce persistence and phenotype switching remain unknown [3, 4]. This project was designed to investigate the impact of the stringent stress response on S. aureus SCVformation and persistence. The stringent stress response is initiated by a rapid synthesis of the alarmones ppGpp and pppGpp, mediated by RSH, RelP and RelQ enzymes [5, 6]. Single, double and triple staphylococcal mutants were generated in S. aureus strains LS1 and USA300 to decrease levels of enzymes involved in the stringent response (∆rsh; ∆rsh/relP, ∆rsh/relQ, ∆rsh/relP/relQ). First experiments were performed to study the bacterial uptake by endothelial cells and cell death. No differences were observed between wild type (WT) and stringency response mutants in both backgrounds. The mutants were tested also for persistence and formation of SCVs in EA.hy926 (endothelial cells) culture systems. Seven days after infection of endothelial cells the number of intracellular CFU/ml recovered did not differ between WT and mutant strains. Moreover, the percentage of SCVs formed was not statistically significant in any of the tested strains. To analyse possible escape from intracellular degradation mechanisms phagosome escape in A549 cells (epithelial cells) was tested. The percentage of bacteria in cytoplasm did not differ in any of the tested strains. In conclusion, we did not find an impact of the stringent response on acute phase of infection as cell death and cell invasion were not affected. Moreover, it was not found a relation between long-term intracellular persistence of S. aureus in endothelial cells and stringency response, although the system was reported to contribute to intracellular persistence in other pathogens. [1] Lowy, FD. (1998) Staphylococcus aureus infections. N Engl J Med 339: 520-32. [2] Tuchscherr, L., Bischoff, M., Lattar, SM., Noto Llana, M., Pförtner, H., Niemann, S., et al. (2015) Sigma Factor SigB Is Crucial to Mediate Staphylococcus aureus Adaptation during Chronic Infections. PLoS Pathog 11(4):e1004870. [3] Tuchscherr, L., Medina, E., Hussain, M., Völker, W., Heitmann, V. et al. (2011) Staphylococcus aureus phenotype switching: an effective bacterial strategy to escape host immune response and establish a chronic infection. EMBO Mol Med 3: 129-141. [4] Proctor, RA., von Eiff, C., Kahl, BC., Becker, K., McNamara, P. et al. (2006) Small colony variants: a pathogenic form of bacteria that facilitates persistent and recurrent infections. Nat Rev Microbiol 4: 295-305. [5] Wolz, C., Geiger, T., Goerke, C. (2010) The synthesis and function of the alarmone (p)ppGpp in firmicutes. Int J Med Microbiol 300: 142-147 [6] Geiger, T., Francois, P., Liebeke, M., Fraunholz, M., Goerke, C. et al. (2012) The Stringent Response of Staphylococcus aureus and Its Impact on Survival after Phagocytosis through the Induction of Intracellular PSMs Expression. PLoS Pathog 8(11):e1003016.

POSTERS - PATHOGENESIS Staphylococcus aureus pathogenesis: from sepsis to hematogenous chronic bone infections. Christine Pöllath, Bettina Löffler, Lorena Tuchscherr Institute for Medical Microbiology, Jena University Hospital, Jena, Germany Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany Staphylococcus aureus is a bacterium, which is able to colonize epithelial surfaces of healthy individuals, as well as causing acute to chronic infections, for example in the bone[1]. The aim of this work was to detect characteristics of isolates that cause hematogenous osteomyelitis. To elucidate the connection of sepsis and chronic bone infections, a strain collection was established. It was divided into four different categories: nasal colonization of healthy persons, sepsis without metastasis, osteomyelitis with and without hematogenous origin. Those groups were genotyped for their clonal complex, resistance profile and different virulence and adhesin genes. Only minor differences between the groups could be observed. Different stages of infection were mimicked with in vitro experiments. The ability to produce biofilm is coupled with the expression of adhesins [2]. The strains were tested for their biofilm formation on plastic surface, though the differences between the groups were not significant. To test the invasiveness and cytotoxicity, flow cytometric assays were used, which resulted in no significant differences regarding the ability to invade host cells. In contrast, the group of non-hematogenous osteomyelitis showed a significant lower cytotoxicity, compared with the isolates belonging to the colonizing and sepsis group. To picture the cytotoxicity in more detail, a hemolysis assay was performed. A significant difference was found between the group of nasal colonizing strains and the hematogenous osteomyelitis group, whereas the latter showed a higher hemolysis grade of sheep blood erythrocytes. The preliminary data suggests that strains, which are related to the bloodstream tend to show a higher cytotoxicity regarding their ability to destroy osteocytes and erythrocytes. A more detailed understanding of how S. aureus interacts with the host could ultimately lead to potential targets for new therapeutics to help control staphylococcal infections. [1] Lowy , F.D., Staphylococcus aureus Infections. New England Journal of Medicine, 1998. 339 (8): p. 520-532. [2] Archer, N.K., et al., Staphylococcus aureus biofilms. Virulence, 2011. 2(5): p. 445-459.

How do phytoplasmas generate ‘zombie plants’? Interaction of the bacterial effector protein SAP54 with floral homeotic proteins

Marc-Benjamin Aurin [1],Florian Rümpler [2], Matthias Görlach [3], Günter Theißen [4] [1] Friedrich-Schiller-University Jena, ILRS, JSMC, [2] Friedrich-Schiller-University Jena, [3] Fritz Lipman Institute Jena, [4] Friedrich-Schiller-University Jena Phytoplasmas are pathogenic bacteria that are obligate parasites of plants and transmitting insects [13]. They can cause devastating plant diseases, e.g. by reprogramming development in a way such that leaf-like structures instead of floral organs occur. Infected plants are thus often sterile, mainly serve to reproduce phytoplasmas and hence have been termed ‘zombie plants’ [1, 3]. The molecular mechanism underlying the developmental reprogramming relies on specific interactions of a secreted phytoplasma protein called SAP54 (or PHYLLOGEN1) with a subset of MIKC-type MADS-domain transcription factors involved in controlling flower development [1, 2]. The secreted part of SAP54 interacts with the keratin-like domain (K domain) of MIKC proteins and destines them for degradation [1], so that they cannot constitute ‘floral quartets’ anymore, the protein complexes that specify floral organ identity [4]. Based on the recently published X-ray crystal structure of a K domain and detailed in silico analyses [5, 6] we have developed three hypotheses: i) SAP54-like proteins form a structure which is very similar to that of the K domain; ii) The interaction between SAP54 and the plant MIKC proteins is mediated by a mechanism that resembles the interaction of two K domains in floral quartets; iii) SAP54 mimics the K-domain structure as a result of convergent protein evolution [6]. We want to test these hypotheses by determining the structure of SAP54-like proteins and studying the interaction between these proteins and MIKC proteins. [1] MacLean AM, et al. (2014) PLoS Biol 12, e1001835 [2] Maejima K, et al. (2014) Plant J 78, 541-554 [3] Du Toit A (2014) Nature Rev Microbiol 12, 393-393 [4] Gramzow L, Theißen G (2010) Genome Biol 11, 214 [5] Puranik S, et al. (2014) Plant Cell 26, 3603-3615. [6] Rümpler F, et al. (2015) Trends Plant Sci (in press)

Investigation of protein interactions to elucidate the function of unknown proteins of the human pathogenic fungus Aspergillus fumigatus Marcel Noßmann [1], Falk Hillmann [2], Axel Brakhage [2], Thomas Munder [1] [1] Ernst-Abbe-Hochschule Jena, Fachbereich Medizintechnik und Biotechnologie, Jena [2] Leibniz-Institut für Naturstoff-Forschung und Infektionsbiologie e. V. - Hans-Knöll-Institut, Jena The saprophytic fungus Aspergillus fumigatus is considered as the most prevalent and dangerous airborne fungal pathogen. Its natural habitat is or-

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ganic waste, compost and flower soil as well as in wallpapers [2]. It produces different types of secondary metabolites causing several respiratory allergies, contributing to e.g. asthma and allergic sinusitis. In immunocompromised patients, the spores are able to reach the alveoli and cause an invasive infection with a mortility up to 90 % [1,4,8]. The function of approximately 95 % of the 9,926 predicted genes is still unknown. Especially in regard to its pathogenicity, the elucidation of protein function and the investigation of molecular pathways is of great importance [3,9]. We applied the yeast two hybrid technology to identify novel protein/protein interactions using a hypothetical protein as bait. This method is a test system to study protein-protein interactions in vivo. [6,7]. Unfortunately, we cannot use this technology to express the proteins of A. fumigatus in the baker’s yeast Saccharomyces cerevisiae. Due to the differences in codon usage of S. cerevisiae and A. fumigatus and a resulting lack of codon specific tRNA molecules in yeast, proteins could not be sufficiently expressed to study interaction via the chosen system. To solve this problem, we generated a tRNA adapted S. cerevisiae strain which is able to translate the proteins of the fungus more effectively. Transcriptomic analyses showed that this protein has a high abundance during hypoxia and iron starvation and it has a predicted mitochondrial targeting sequence. We found a putative pyruvate decarboxylase (pdcA) which interacts with the hypothetical protein. Further in vitro analyses will be performed to verify this putative protein protein interaction. The investigation of protein function leads to a better understanding of the human pathogen A. fumigatus and its pathogenicity and might provide new targets for novel drugs or diagnostic methods. [1] Paoletti, M., Rydholm, C., Schwier, EU., Anderson, MJ., Szakacs, G., Lutzoni, F., Debeaupuis, JP., Latgé, JP., Denning, DW., Dyer, PS.: Evidence for sexuality in the opportunistic fungal pathogen Aspergillus fumigatus. Current Biology 15, 1242-1248 (2005). [2] Deutsche Gesellschaft für Hydrokultur e.V., Euler, J.: Gießkannenschimmel Aspergillus, Artikel-ID: 1283, 16.10.2012, http://www. dghk.net/friends/parser.php?uid=1283 (2010). [3] Nierman, W.C. et al.: Genomic sequence of the pathogenic and allergenic filamentous fungus Aspergillus fumigatus. Nature 438, 1151-1156 (2005). [4] Latgé, JP. : Aspergillus fumigatus and Aspergillosis, Clin. Microbiol. Rev. 12, 310-350 (1999). [5] Abad, A., Fernández-Molina, J., Bikandi, J., Ramírez, A., Margareto, J., Sendino, J., Hernando, FL., Pontón, J., Garaizar, J., Rementeria, A.: What makes Aspergillus fumigatus a successful pathogen? Genes and molecules involved in invasive aspergillosis. Revista Iberoamericana de Micología 27, 155-182 (2010). [6] S. O. Fields S., A novel genetic system to detect protein-protein interactions.,Nature, 340, 245-246 (1989). [7] Mihatsch, K., Nestler, M., Saluz, H.-P. Henke, A., Munder, T.: Proapoptotic protein Siva binds to the muscle protein telethonin in

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cardiomyocytes during coxsackievial infection. Cardiovasc. Res. 81, 108-115 (2009). [8] Ande rson, M.J., Brookman, J.L., and Denning, D.W. (2003). Aspergillus. In Genomi cs of Plants and Fungi, R.A. Prade and B.J. Bohnert, eds. (New York: Marcel Dekker), pp- 1-39. [9]www.aspergillusgenome.org/cache/A_fumigatus_ Af293_genomeSnapshot.html Aspergillus fumigatus Af293 Genome Snapshot/Overview (17.11.16)

The role of the transcription factor Ahr1 in ECE1 expression in Candida albicans Sophia Ruben [1], Ronny Martin[1], and Oliver Kurzai [1,2] [1] Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Jena, Germany [2] National Reference Center for Invasive Fungal Infections, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Jena, Germany The commensal fungus Candida albicans is able to colonize and invade host tissue of immunocompromised individuals. One of the fungus’ major virulence traits is believed to be the ability to switch from yeast to hyphal growth forms. It is associated with the upregulation of core filamentation response genes such as ALS3, ECE1 and HWP1. Several transcription factors contribute to the regulation of these genes and the hyphal morphology. Recently, regulator Ahr1 was shown to be involved in several processes like white-opaque switching, biofilm formation and interaction with human immune cells. As this transcription factor is specific for C. albicans and close relatives, we examined if it is also contributing to the activation of core filamentation response gene expression. Consequently, we investigated the morphology of mutants either lacking AHR1 or expressing a hyperactive AHR1 allele. Subsequently, qRT PCR was performed to study the expression of core filamentation response genes. Even though C. albicans ahr1∆ mutants formed phenotypically normal hyphae in serum-containing medium, the transcription of ECE1 in these mutants was significantly lower than in wild type hyphae yet still higher than in wild type yeast cells. In contrast to this, the hyperactive AHR1 allele induced high levels of ECE1 expression even under yeast growth conditions. Additionally, the hyperactive AHR1 allele significantly induced ECE1 expression and hyphal growth in cph1∆/efg1∆ mutants, which are usually only able to form yeast cells. These preliminary results suggest that the transcription factor Ahr1 is required for high level transcription of the ECE1 gene. Surprisingly, a hyperactive allele of this regulatory gene can bypass the absence of hyphal growth stimulation to induce ECE1 transcription.

POSTERS - PATHOGENESIS This novel mechanism of ECE1 regulation seems to be independent from the well-known regulators of hyphal growth, Cph1 and Efg1. Evaluation of Electrochemiluminescence and enzyme-linked immunosorbent assays for diagnosis of toxoplasma infections in pregnant women Blerta Laze, Aarta Lugaj Department of Biology, Faculty of Technical Sciences, University “Ismail Qemali”, Vlora, Albania Unidentified gestational infection with Toxoplasma gondii may lead to fetal infection with severe complications later in childhood. Diagnosis of maternal infections solely depends on serology, so routine tests with high sensitivity and specificity are required . This article compares the electrochemiluminescence immunoassay (ECL, applied in COBAS 6000 instrument) with an enzyme-linked immunosorbent assay (ELISA, applied in CHORUS instrument) for early diagnosis of Toxoplasma gondii infections in pregnant women. The evaluation of the results showed a good concordance between the two immunoassays but at the same time a better performance of ECL immunoassay as a first-line screening method to detect gestational Toxoplasma gondii infections. Anyway, for diagnostic purposes, the results should always be assessed in conjuction with the patient’s medical history and other clinical examinations. The human pathogenic fungus Aspergillus fumigatus counteracts phagolysosomal function by interference with flotillin-dependent lipid rafts through conidial melanin Franziska Schmidt [1,2], Marie Röcker [1,2], Hella Schmidt[1,2], Andreas Thywissen [1,2], Martin Westermann [3], Thorsten Heinekamp [1], Scott G. Filler [4], Axel A. Brakhage [1,2] [1] Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Jena, Germany [2] Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany [3] Electron Microscopy Center, Jena University Hospital, Jena, Germany [4] Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, California, USA The filamentous fungus Aspergillus fumigatus is the most important airborne fungal pathogen of humans. A crucial virulence determinant is represented by the dihydroxynaphthalene (DHN)-

melanin layer of the conidia. After inhalation, conidia are recognized and phagocytosed by immune cells. Within the phagosome of alveolar macrophages the conidia get into contact with the phagolysosomal membrane, which is composed of lipid rafts, i.e., defined membrane domains with a distinct lipid composition and high cholesterol content. Lipid rafts form dynamic signaling platforms. The chaperone flotillin presumably structures lipid rafts and represents a major marker protein. To elucidate the role of flotillins in the acidification of phagolysosomes, bone marrow derived macrophages (BMDMs) of Flot-1/-2 knock out mice were compared to C57BL/6 wild-type cells. BMDMs were co-incubated with DHN-melanin coated wild-type A. fumigatus conidia as well as pigmentless pksP mutant conidia. We showed that melanized conidia reduce phagocytosis ability, interact with the phagolysosomal membrane and lead to the disturbance of lipid raft microdomains. Thereby the assembly and activity of the vATPase complex is inhibited and the acidification of the phagolysosome is prevented. Furthermore, the assembly of the NADPH oxidase complex, which is required for microbial killing through the generation of reactive oxygen species, was reduced by melanized conidia. In Flot-1/-2 knock out BMDMs, acidification of phagolysosomes was impaired and assembly of vATPase and NADPH oxidase on the phagolysosomal membrane was reduced. In summary, we showed that melanized wild-type conidia interfere with the formation of flotillin-containing lipid raft microdomains in the phagolysosomal membrane. Phagolysosomes devoid of lipid rafts fail to assemble the vATPase to drive phagolysosomal acidification thereby providing a niche for A. fumigatus to survive inside the host. Candida albicans genes associated with translocation through intestinal epithelial barriers Stefanie Allert [1], Toni Förster [1], Marc Juraschitz [1], Daniela Schulz [1], Betty Hebecker [1,2], Tony Pawlik [2], Ilse D. Jacobsen [2,3,4], Lydia Kasper [1], Bernhard Hube [1,3,4] [1] Department of Microbial Pathogenicity Mechanisms, Hans-Knöll-Institute, Jena, Germany [2] Research Group Microbial Immunology, HansKnöll-Institute, Jena, Germany [3] Center for Sepsis Control and Care, University Hospital Jena, Germany [4] Friedrich-Schiller-University Jena, Germany The opportunistic pathogen Candida albicans can cause life-threatening systemic infections, which predominantly originate from the commensal C. albicans population of the intestinal tract. However, the molecular mechanisms of C. albicans translocation from the gut into the bloodstream are not

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well characterized. The aim of this project is to characterize the processes associated with damage of and translocation through intestinal epithelium and to define potential pathogenicity mechanisms and factors required for intestinal tissue invasion. First, we characterized the processes associated with epithelial damage and fungal translocation through intestinal epithelia layers using an in vitro translocation model. Our data show that C. albicans translocation mainly occurs via a transcellular route and requires fungal-induced epithelial damage. This correlates with necrosis, but not apoptosis of intestinal cells. Screening of C. albicans deletion mutant libraries identified several mutants with altered capacity to damage intestinal cells. Selected mutants with reduced damage potential were analyzed for their invasive potential and impact on epithelial barrier function in the translocation model. Identified damage-associated genes have predicted functions in filamentation, biofilm formation, vacuolar or cell wall organization, stress response or metabolic as well as transcriptional processes. Moreover, we found a number of unknown function genes associated with damage of intestinal cells. The corresponding damage-defective C. albicans mutants were phenotypically characterized with a focus on morphology and other infectionassociated attributes. Of note, almost every mutant showed a unique pattern of defects indicating that several biological properties are required for full damage potential. Reduced damage of intestinal cells was often, but not always, correlated with filamentation defects or decreased translocation ability of C. albicans mutants. Hence, translocation does not necessarily require damage, which is why contribution of tight junction-associated paracellular mechanisms is currently under investigation.

cently, it was shown that the Ece1p precursor is processed into eight fragments. One of the resulting peptides, Ece1p-III, exclusively has cytolytic activity and causes damage to host cell membranes. Thus, the characterization of the regulation of this virulence gene can contribute to a better understanding of C. albicans pathogenesis. As other core filamentation response genes like ALS3 and HWP1, ECE1 has a very long 5’ intergenic region of more than 3000 bp. In this study we explore which parts of the intergenic region are required for the regulation of ECE1 in yeast and hyphal cells. For that purpose, various fragments of the intergenic region consisting of the first 500 bp up to the whole length region were fused to GFP and ectopically integrated into the C. albicans NEUT5L locus. The resulting mutants were screened microscopically for GFP signals in diverse hyphae-inducing conditions. In addition, GFP mRNA levels were verified via qRT-PCR. C. albicans strains with GFP under the control of the first 1000 or less bp of the intergenic region did not show any detectable fluorescence. The minimum size of a promoter resulting in detectable fluorescence was 1200 bp, while 1500 bp was determined as the minimum size sufficient for full-level transcription. However, a deletion of the first 1000 bp led to the absence of detectable GFP signals, indicating their importance for full activation of ECE1. Consistent with that, the active TATA box for ECE1 was identified within the first 110 bp resulting in a notably short 5’ UTR, contrary to the unusual long 5’ intergenic region. Taken together, we presume that the ECE1 promoter consists of at least 1500 bp. The characterization of this active region will allow further experiments to define the nature as well as the dynamics of transcription factors binding to this promoter.

Characterization of the Candida albicans ECE1 promoter Enrico Garbe [1,2], Ronny Martin [1,2], Slavena Vylkova [2] and Oliver Kurzai [1,3,4] [1] Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology Hans Knoell Institute, Jena, Germany [2] Research Group Host Fungal Interfaces, Friedrich Schiller University, Jena, Germany [3] Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany [4] National Reference Center for Invasive Fungal Infections, Leibniz Institute for Natural Product Research and Infection Biology Hans Knoell Institute, Jena, Germany

Characterizing innate immune cell activation by fungal pathogens using Live cell imaging Alessandra Marolda [1], Kerstin Hünniger [1,2], Naim Al-Zaben [2], Marc Thilo Figge [2], Oliver Kurzai [1,2] [1] Septomics Research Center, Friedrich Schiller University, Jena [2] Leibnitz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Jena

Candida albicans ECE1 is exclusively expressed in hyphae and therefore it can be used as a marker for filamentation-associated gene expression. Re-

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Invasive fungal infections are emerging as a significant health risk for humans. In this regard, Candida albicans and Candida glabrata are two most prevalent pathogens in the genus Candida and account for the majority of candidiasis cases worldwide. Although these two species share some of the same virulence factors, they are phylogenetically quite distinct. Consequently, there is also evidence that the interplay of C. albicans and C. glabrata with the human immune system differs considerably; in fact

POSTERS - PATHOGENESIS they have evolved different mechanisms to escape cellular immune responses. We are using live cell imaging, a modern approach that allows visualization of cell-cell and cell-microbe interactions and real-time analysis of dynamic biological processes, to characterize the interaction between specific innate immune cell populations (neutrophils, monocyte and Natural Killer) and the two Candida spp. A major aim of this project is to image the interaction between different types of immune cells, e.g. NK cells and monocytes, or neutrophils and dendritic cells and follow the confrontation assay of these different combinations in the presence of C. albicans or C. glabrata. Live cell imaging has already been established in the lab to investigate the interaction of primary human neutrophils with C. albicans and C. glabrata and could show that the two Candida species are differentially recognized by these immune cells. Imaging data will be provided to the bioinformatics group of Prof Figge to develop modeling approaches for automated image analysis. This will allow quantification of parameters like (a) efficacy of phagocytosis after contact with pathogen, (b) frequency of phagocytosis events, (c) avarage speed of cellular motility, (d) directionality of motility and (e) kinetics of fungal killing to analyze the behavior of different immune cells in relation with different Candida species. Combining this information obtained from live cell imaging and bioinformatic analysis will be part of a broader project, InfectoOptics project BLOODI, with the aim to combat infectious disease with optical technologies by establishing the concept of a dynamic hemogram from blood infection assays. Iron regulation in the pathogenic fungus Aspergillus fumigatus: Functional domain analysis of the central regulator HapX Mareike Scheven [1,2], Matthias Misslinger [3], Peter Hortschansky [1], Hubertus Haas [3], Axel A. Brakhage [1,2] [1] Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Jena, Germany [2] Friedrich Schiller University, Jena, Germany [3] Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria Aspergillus fumigatus is a ubiquitous saprophytic mould, which causes life-threatening diseases in immunocompromised patients. During infection, sufficient iron supply is crucial for fungal growth. Iron is a vital nutrient, but can be harmful in excess by triggering the formation of cell damaging reactive oxygen species. As a result, A. fumigatus has evolved fine-tuned mechanisms to maintain iron equilibrium. Adaptation to iron limitation is

mediated by the bZIP transcription factor HapX, which represses iron consuming pathways and activates iron uptake. Additionally, HapX contributes to resistance against iron excess by activation of vacuolar iron storage. For gene repression during iron starvation and activation of iron detoxification, the physical interaction of HapX with the heterotrimeric CCAAT-binding complex (CBC) is essential. Currently, it is unclear whether cooperation of HapX with the CBC is also required for gene activation under low-iron conditions. Via surface plasmon resonance interaction analysis using recombinant A. fumigatus CBC and HapX proteins that included deletion of the CBC-binding domain (BD) or mutation of four amino acids within the DNA-BD, we demonstrate here that both the CBCand DNA-BDs of HapX are mandatory for combinatorial sequence-specific DNA-binding of the CBC and HapX in vitro. In agreement, lack of the HapX CBC-BD or mutation of the HapX bZIP domain phenocopied HapX-deficiency in vivo. Interestingly, deletion of the CBC-BD had a greater impact on siderophore biosynthesis than mutation of the DNA-BD. In addition, we showed in vitro that CBC-HapX cooperation is essential for discrimination between HapX and Yap1 target genes. HapX and Yap1 contain almost identical DNA-BDs, but regulate different processes in vivo. In summary, these data provide first evidence for combinatorial DNA-binding of HapX with the CBC to activate siderophore biosynthesis during iron starvation. Actinobacteria – a source for antivirulence leads? Nico Ortlieb, Elisa Liebhart, Timo H. J. Niedermeyer IMIT / Antiinfective Natural Products, University of Tübingen, Tübingen, Germany The spread of antibiotic drug resistances and the occurrence of multidrug resistant bacteria are one of the major threats of the 21th century, as they lead to infections that cannot be treated adequately. Therefore, it is inevitable to exploit new treatment strategies and detect new targets to overcome resistances. The interference with bacterial virulence or biofilm production by inhibition of bacterial quorum sensing (QS) is such a new approach [1]. The term “quorum sensing” has been coined for intercellular communication systems, which allow bacteria to sense their direct environment in order to examine the particular cell density [2]. Inhibition of these systems is seen as a promising strategy to treat bacterial infections since bacterial growth is not affected and thus emergence of resistance is not very likely [3]. Although actinomycetes potentially produce compounds that inhibit QS, only few studies have been reported [4]. Therefore, about 1200 strains of the Tübinger actinomycetes

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strain collection have been screened for inhibition of quorum sensing using the reporter strains C. violaceum CV026 and S. aureus PC322 [5] after the development of a medium-throughput agar plug assay based screening system. Several strains inhibiting QS in one or the other of the reporter strains could be identified. In order to isolate bioactive compound, extracts of the respective strains have been subjected to bioactivity guided fractionation using several chromatographic techniques like Flash chromatography and high-performance liquid chromatography (HPLC). Structure elucidation of these compounds via nuclear magnetic resonance spectroscopy (NMR) and tandem high resolution mass spectrometry (HRMSn ), followed by detailed bioactivity and toxicity characterization is currently in the works. [1] Clatworthy AE., Pierson E. (2007). Targeting virulence: a new paradigm for antimicrobial therapy. Nat Chem Biol, 3, 541-548. 10.1038/nchembio.2007.24 [2] Waters CM., Bassler, B.L. (2005). Quorum Sensing Cell-to-Cell Communication in Bacteria. Annu Rev Cell Dev Biol, 21, 319-346. 10.1146/annurev.cellbio.21.012704.131001 [3] Gerdt JP., Blackwell HE. (2014). Competition studies confirm two major barriers that can preclude the spread of resistance to quorum-sensing inhibitors in bacteria. ACS Cem Biol, 9, 2291-2299. 10.1021/cb5004288 [4] Desouky SE., Nishiguchi K. (2013). High-throughput screening of inhibitors targeting Agr/Fsr quorum sensing in Staphylococcus aureus and Enterococcus faecalis. Biosci Biotechnol Biochem, 77, 923927. 10.1271/bbb.120769 [5] Nielsen A., Nielsen KF. (2010). Method for screening compounds that influence virulence gene expression in Staphylococcus aureus. Antimicrob Agents Chemother, 54, 509-512. 10.1128/AAC.00940-09

Characterization of Aspergillus fumigatus mutants regarding their interactions with human leukocytes Mai Hoang [1], Martin Föge [1,3], Susann Hartung [1,3], Juliane Macheleidt [2], Axel A. Brakhage [2,3], Marie von Lilienfeld-Toal [1,3] [1] Department Infections in Hematology and Oncology [2] Department Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Jena, Germany [3] Clinic of Internal Medicine II, Department Hematology and Oncology, and Center for Sepsis Control and Care, University Hospital Jena, Jena, Germany Infection by Aspergillus fumigatus in immunocompromised patients upon inhalation of asexually formed conidia can lead to life-threatening diseases, such as invasive aspergillosis. It has been shown that A. fumigatus conidia cell wall components contribute to fungal virulence. However, the roles of these surface molecules and the mechanisms underlying the interaction between A. fumigatus and human innate immune cells are not fully

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understood. In our study, we focus on the characterization of selected genes putatively involved in synthesis and structure of cell wall components and surface molecules by means of testing single knock-out mutants. We found that neutrophils and monocytes showed a significantly decreased phagocytosis of the mutant strain ∆rodA compared to the wild-type during 4 hours of co-incubation, however, no difference in ROS production was seen. In contrast, the mutant strain ∆pksP, which is defective of the production of fungal cell wall melanin, induced a significantly increased ROS production (2.5 fold higher) by neutrophils, accompanied by a significantly higher phagocytosis rate compared to the wild type. This points at the important role of 1,8-DHN melanin for immune evasion. However, the phagocytosis rates and ROS productions induced by other GPI mutants (e.g. Δbgt2, Δecm33, Δutr2, Δmp2 ) in comparison with A. fumigatus wild-type showed only subtle changes. In ongoing studies, our data will be complemented by more detailed characterization of the above mentioned mutant strains in their spore size and germination ability. Analysis and differentiation of the small colony variant phenotype of Staphylococcus aureus in comparison to the wildtype using Raman spectroscopy Frederike Gladigau [1], Christina Ebert [1,2], Lorena Tuchscherr [1,3], Bettina Löffler [1,3,5], Jürgen Popp[1,2,4,5], Ute Neugebauer [1,2,4,5] [1] Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany [2] Leibniz Institute of Photonic Technology, Jena, Germany [3] Institute for Medical Microbiology, Jena University Hospital, Jena, Germany [4] Institute of Physical Chemistry and Abbe School of Photonics, Friedrich Schiller University Jena, Germany [5] InfectoGnostics Research Campus Jena, Jena, Germany The human pathogen S. aureus is widespread and approximately 20% of individuals are persistently colonized. The bacteria can lead to serious infections and are a major cause of sepsis. Furthermore, they are able to cause relapsing infections by persisting intracellularly [1]. This lifestyle could recently be connected to the phenotypical switch between wild-type and the small colony variant (SCV) phenotype. SCVs have a reduced metabolism and toxin production. This adaptation to the intracellular milieu allows the bacteria to survive inside the host cell and to escape from the immune system [2]. Until now the standard method to differentiate between wild-type and SCV is to extract the bacteria from the tissue

POSTERS - PATHOGENESIS and plate them. This needs around 48-72 hours of incubation till SCV colonies are visible [2]. Thus, imaging methods that can analyse the bacteria directly in the host cell are of utmost interest in order to better understand the pathogenesis of chronic infections. Raman spectroscopy is a label-free and non-invasive method which uses monochromatic laser light to record fingerprint-like information from the sample. As light-matter interactions are fast, this method allows for data extraction within much shorter time frames. Furthermore it could be shown that this method allows for the identification and characterization of intracellular S. aureus directly in the host cell without isolating the bacteria [3]. Here, we show how to use Raman spectroscopy to differentiate between wild-type and stable SCVs. Raman spectra for both phenotypes have been recorded for different S. aureus strains. Characteristic spectral differences between the wildtype and the SCV phenotype can be used in future work as marker bands to differentiate the two phenotypes also inside the host cell. Our results demonstrate that the Raman spectroscopy holds many promising possibilities for the analysis of intracellular bacteria without the time consuming process of isolating them from the host cell. Acknowledgement: Financial support by the BMBF via the Integrated Research and Treatment Center ’Center for Sepsis Control and Care’ (FKZ 01EO1502) is highly acknowledged. [1] Garzoni C, Kelly WL (2009) Staphylococcus aureus : new evidence for intracellular persistence. Cell Press Trends in Microbiology 17.2: 59-65 [2] Tuchscherr L, Medina E, Hussain M, Völker W, Heitmann V, Niemann S, Holzinger D, Roth J, Proctor R, Becker K, Peters G, Löffler B (2011) Staphylococcus aureus phenotype switching: an effective bacterial strategy to escape host immune response and establish a chronic infection. EMBO Mol Med 3: 129-141 [3] Große C, Bergner N, Dellith J, Heller R, Bauer M, Mellmann A, Popp J, Neugebauer U (2015) Label-Free Imaging and Spectroscopic Analysis of Intracellular Bacterial Infections. Anal. Chem. 87: 21372142

Effect of different resin composite monomers (methacrylate and silorane) on two cariogenic bacteria / In vitro study Marwa Mohamed Elsheikh [1], Ahmed Ali Musrati [2], Ahmed Safwat Elkady [3] [1] El Sheikh Center (Private Sector) [2] Department of Operative Dentistry, Faculty of Dentistry, University of Alexandria, Egypt [3] Department of Pediatric Dentistry, Faculty of Dentistry, University of Benghazi, Libya Background & Objectives: The biological response of oral bacteria to dental restorative polymer composites is mediated by the release of unpolymerized residual monomers. The aims of the present

study were, firstly: evaluating the effect of composite elutes from methacrylate composite resins and Silorane-based composites on two cariogenic bacterial pathogens: Streptococcus mutans and Lactobacillus acidophilus . Secondly: determination of degree of conversion of standardized discs made from the low shrinkage silorane-based composite (FiltekTM P90) resin and methacrylate-based composite resin (FiltekTM Z350XT nanocomposite, FiltekTM Z350 Flow) using Fourier Transform Infra-red Spectroscopy (FTIR). Materials & Methods: Thirty six composite specimens were prepared for the agar diffusion test and dissolved in a solvent (dimethyl sulphoxide, DMSO) to attain a suspension, which was used to assess the effect of the residual monomers from methacrylate composite resins and silorane-based composites on the growth of S. mutans and L. acidophilus. The colonies of bacteria were counted by naked eye. Thirty composite specimens 2mm × 6mm were polymerized for degree of conversion test (DC); and the DC was measured using FTIR, also for unpolymerized composite resin. Results: The growth of S. mutans bacteria was inhibited when cultured with Filtek Z350 Flow composite resin while the growth of L. acidophlius bacteria was stimulated by the Filtek silorane p90 and Filtek Z350 Flow composite resin. The DC test with the Filtek silorane composite resin showed highest degree of conversion (58%), then the Filtek Z350XT (Nanocomposite) (42%) followed by the Filtek Z350 Flow (Flowable) as the lowest (35%). Conclusion: Our results demonstrate that composite filling materials have a versatile nature of effect on oral pathogenic bacteria, which could modulate their pathogenesis. Dentists may thus select the appropriate type of composite filling according to the caries susceptibility of patients. Serosurvey of Crimean-Congo Hemorrhagic Fever Virus Among Sheep and Goats in Lezhe District of Albania Arta Lugaj [1], Blerta Laze [1], Isolde Schuster [2], Marc Mertens [2], Martin Groschup [2], Kristaq Berxholi [3] [1] Department of Biology, “Ismail Qemali” University of Vlora, Albania [2] Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute, Greifswald, Germany [3] Department of Veterinary Public Health, Agricultural University of Tirana, Albania Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral disease that causes a fatal hemorrhagic illness in humans, caused by a high-risk group of viruses belonging to the family Bunyaviridae . Humans can be infected by bites from infected ticks, mainly of the Hyalomma genus, by un-

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protected contact with blood or tissue of viremic patients, or during slaughtering of infected animals. CCHF is widespread in various countries in Africa, Asia, and Europe [1]. In the present study, a seroepidemiological survey was conducted to determine the prevalence of CCHF infection and to identify the potential risk factors associated with the disease among sheep and goats in Lezhe district of Albania. Blood samples were taken from the jugular vein of 10 goats in Lezhe-Torovice, 68 goats in Lezhe-Mamurras, 9 sheep in Lezhe-IshullShengjin, 9 sheep in Lezhe-Torovice, 10 sheep in Lezhe-Kolojak and 10 sheep in Lezhe-Ishull-Lezhe. A total of 116 serum samples respectively 78 samples from goats and 38 samples from sheep were screened for IgG antibodies using a CCHF animal IgG enzyme-linked immunosorbent assay (ELISA) kit at Friedrich-Loeffler-Institute (FLI), Greifswald Germany. Antibodies were detected in ruminant animals in Lezha district of Albania with positivity of 34.2% in sheep and 19.23% goats, respectively. The results of our study highlight the suitability of small ruminants as indicator animals for seroepidemiological CCHFV monitoring studies to determine the presence or absence of CCHFV in a given region [1]. It is recommended that surveillance of CCHF infection should be extended to include other ruminant animals and to study the distribution of Hyalomma ticks in the region especially in endemic districts, for a better prevention of any autbreak of CCHF infection in Albania. [1] Schuster I, Mertens M, Mrenoshki S, Staubach C, Mertens C, Bruning F, Wernike K, Hechinger S, Berxholi K, Mitrov D, Groschup M (2016) Sheep and goats as indicator animals for the circulation of CCHFV in the environment. Springer 68:337-346

Antimalarial potential of Liposomal Zinc pyrithione Mohsin Raza, Prahlad C Ghosh Department of Biochemistry, University of Delhi South Campus Malaria, an infectious disease, caused by Protozoan parasite of genus Plasmodium. Among the plasmodium species infecting humans, Plasmodium falciparum is the most deadly. Despite various advances in modern science combating malaria is a challenging task due to lack of effective vaccine and emergence of drug resistance parasite towards most of the antimalarials. Thus there is always a need of discovery of new potent antimalarial compounds or development of effective drug delivery vehicles which can overcome the problem of drug resistance. In the present study, we have evaluated the growth inhibitory efficacy of Liposomal Zinc pyrithione on the blood stages of Plasmodium falciparum in culture and as well as we have studies the therapeutic efficacy of these liposomal formulation

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in treating the murine model of malaria. Our results depict that Zinc pyrithione, which is known for its antifungal action has potent antimalarial action against the growth stages of Plasmodium falciparum in culture and moreover it’s liposomal formulation is effective in curbing down the blood parasite load of treated animals in murine model of malaria. Overall, our results strengthen the importance of drug delivery for the treatment of infectious diseases and our formulation of liposomal zinc pyrithione may be considered as a novel strategy to curb down this deadly infectious disease. Iron redistribution after Candida albicans infection in the murine kidney Agata Kilar [1], Theresia Conrad [2], Jorg Linde [2], Joanna Polanska ´ [1] [1] Silesian University of Technology, Gliwice, Poland [2] Systems Biology/Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology HKI, Jena, Germany Candida albicans has the potential to cause a wide range of infections, what makes it a major human fungal pathogen. One of the most dangerous infections mainly caused by C. albicans is Invasive Candidiasis (IC), which is the fourth most common cause of hospital-acquired systemic infections with crude mortality rates up to 50 % [1]. The innate immune response in this infection entails a series of complex and inter- related interactions between multiple recruited and host cell populations with each other and with the fungal cell. The iron is essential for fungal growth [2]. The systems biology approach with based on agent modelling is a suitable method to represent a complex and multi-level mechanism, such as the immune response to fungal and other pathogens in the kidney. The aim of the presented work was to lay the groundwork for a multiscale dynamic mathematical model of the innate immune response to C. albicans in the kidney, focusing on the “battle for iron” between host and pathogen. Presented model includes the tissue structure with changes in tissue- level iron concentrations, as well as detection of the pathogens by the immune system, which leads to neutrophils recruitment and iron redistribution. The parameter sensitivity analysis was conducted to ensure the model is robust. In this work, two different behaviours of the model were compared with each other in order to determine the effect of the iron redistribution process to the course of IC infection in the kidney. The analysis, which I made, shows that iron redistribution process is essential for eradicating IC infection.This model is the first model focused on this phenomenon and can be used as a tool to investigate IC, as well as test the hypothesis in silico and to explore therapeutic interventions.

POSTERS - CHEMICAL ECOLOGY [1] Mayer F. L., Duncan W. and Hube B.. (2013). Candida albicans pathogenicity mechanisms. Virulence, 4(2), 119-128. [2] Lionakis M. S., Lim J. K., Lee C. R., Murphy P. M.. (2011). OrganSpecific Innate Responses in a Mouse Model of Invasive Candidiasis. J Innate Immun, 3, 180- 199.

Factor H-related protein 1 (FHR1) binds to C. albicans and acts pro-inflammatory in monocytes Sarah Irmscher [1,2], Susana Hidalgo Vico [1], Stefan Lorkowski [2], Christine Skerka [1] [1] Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany [2] Friedrich-Schiller-University, Jena, Germany The complement system is the first line of defence against microbial infections and once activated is tightly regulated by membrane bound and soluble regulators. FHR1, which is known to inhibit the C5 convertase as well as the MAC assembly in fluid phase is recruited by the pathogenic fungus C. albicans. However, bound to surfaces FHR1 acts as complement activator and stimulates the inflammasome in monocytes to release the proinflammatory cytokine IL-1b. In addition antiinflammatory IL-10 is reduced. Monocyte regulation by FHR1 is dependent on normal human serum but independent of complement activation. How FHR1 mediates the pro-inflammatory effect in monocytes and why C. albicans recruits the protein to the surface is still unclear. Studying the role of CgMIP1 in the evolution of Candida glabrata during adaption to the human host Sofía Siscar-Lewin [1], Sascha Brunke [1], Bernhard Hube [1,2,3] [1] Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany [2] Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany [3] Friedrich Schiller University, Jena, Germany Background Candida glabrata is the second most prevalent cause of candidemia worldwide, which is largely due to its high intrinsic and rapidly acquired resistance to azole antifungals. Phylogenetically, C. glabrata is more closely related to Saccharomyces cerevisiae than to the most common Candida species, C. albicans. Recent evolutionary studies have shown that the gene CgMIP1 may have been under positive selection during the evolution of C. glabrata as human pathogen. The ortholog MIP1 in Saccharomyces cerevisiae encodes a mitochondrial polymerase. Defects in mitochondrial functions lead to respiratory deficiency, as described in petite mutants, and increased resistance against azole an-

tifungals. Objective We studied the possible role of CgMIP1 in C. glabrata pathogenicity compared to the non-pathogenic species S. cerevisiae. Methods We created MIP1 knock-out mutants of both species and analyzed their growth under different stress conditions, such as oxidative stress, osmotic stress, endoplasmic reticulum (ER) stress and cell wall stress. Conclusions MIP mutants (mip1Δ) of both species showed petite-like phenotype. Interestingly, the C. glabrata mutant showed steady growth under ER stress conditions, whereas the growth of the wild type and S. cerevisiae strains was notably slower. Hence, deletion of MIP1 conferred a species-specific increased resistance to these stressors for C. glabrata. These adaptations might originally be due to frequent exposure to noxious substances, e.g. originating from the mucosal flora, which made selection pressure on CgMIP1. This could allow loss of function upon certain stressors and better survival in petite-like growth. Further studies are underway to verify this hypothesis.

Chemical ecology Genomic and metabolomic analysis of Termitomyces sp., the fungal mutualist of Macrotermitinae Nina Kreuzenbeck [1], Victoria Challinor [2], Haofu Hu [2], Saria Otani [2], Michael Poulsen [2], Christine Beemelmanns [1] [1] Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute, Chemical Biology of Microbe-Host Interactions, Jena, Germany [2] University of Copenhagen, Department of Biology, Section for Ecology and Evolution, 2100 Copenhagen East Fungus growing termites (Macrotermitinae) cultivate a symbiotic fungus (Termitomyces sp.) for nutrition. The fungus is grown on predigested plant material, which is piled up by the termites as a comb-like structure to enable optimal growth conditions.[1] This environment is prone to exploitation by parasitic fungi (e.g. Pseudoxylaria sp.) if the colony ecosystem is out of balance.[2] Due to the longevity and stability of a healthy termite colony, we hypothesize that the symbiotic food fungus Termitomyces sp. contributes to garden defense beside the termites and other microbial commensals or symbionts, by the production of e.g. antimicrobial natural products.[3] We are investigating the biocatalytic potential of Termitomyces sp. on a genomic, transcriptomic and metabolomic level to understand the ecological role of the encoded natural products in the ancient mutualistic relationship. Based on available genome information, we analyzed the secondary metabolite repertoire.

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We then performed transcriptomic studies coupled with LC-MS and NMR based metabolomics studies. Genome mining revealed the presence of PKS, NRPS, NRPS-like and terpene synthase biosynthetic genes. The expression of genes located in PKS and NRPS gene cluster was confirmed and the expression of NRPS-like and terpene synthase genes is now under investigation. In parallel the metabolome capacity of Termitomyces sp. was investigated by a comparative cultivation approach that revealed the time- and media-dependent production of a great number of different metabolites. We were able to establish a reliable method for studying the biosynthetic repertoire of Termitomyces sp., which will be applied to identify the encoded natural products. [1] a) Aanen, D. K., Eggleton, P., Rouland-Lefevre, C., GuldbergFroslev, T., Rosendahl, S., and Boomsma, J. J. (2002). The evolution of fungus-growing termites and their mutualistic fungal symbionts. Proceedings of the National Academy of Sciences, 99 (23), 1488714892. b) Poulsen, M., Hu, H., Li, C., Chen, Z., Xu, L., Otani, S., . . . Zhang, G. (2014). Complementary symbiont contributions to plant decomposition in a fungus-farming termite. Proceedings of the National Academy of Sciences, 111 (40), 14500-14505. [2] Visser, A. A.; Kooij, P. W.; Debets, A. J. M.; Kuyper, T. W.; Aanen, D. K. (2011). Pseudoxylaria as stowaway of the fungus-growing termite nest: Interaction asymmetry between Pseudoxylaria, Termitomyces and free-living relatives. Fungal Ecology , 4 (5), 322-332. [3] a) Beemelmanns, C.; Guo, H.; Rischer, M.; Poulsen, M. (2016). Natural products from microbes associated with insects. Beilstein Journal of Organic Chemistry ,12 , 314-327. b) Ramadhar, T. R.; Beemelmanns, C.; Currie, C. R.; Clardy, J. (2014). Bacterial symbionts in agricultural systems provide a strategic source for antibiotic discovery. Journal of Antibiotics (Tokyo), 67 (1), 53-58. doi:10.1038/ja.2013.77

Bacterial-algal interactions mediated by siderophores Colette Kurth [1], Markus Nett [2] [1] Leibniz-Institut für Naturstoff-Forschung und Infektionsbiologie, Jena, Germany. Institut für Anorganische und Analytische Chemie, Friedrich-SchillerUniversität Jena, Jena [2] Technische Biologie, Fakultät für Bio- und Chemieingenieurwesen, Technische Universität Dortmund, Dortmund, Germany Iron is an essential element required for many biological key processes. Being almost insoluble under aerobic conditions at physiological pH, iron is hardly bioavailable and very often represents a limiting factor for microbial growth. In order to overcome this challenge, many microorganisms produce siderophores, i.e., strong low molecular weight iron chelators. Upon their secretion, siderophores scavenge Fe(III) from the environment and subsequently provide it to the cell. Photoreactive siderophores are special in that they un-

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dergo photoinduced oxidative cleavage once complexed to Fe(III) [1]. As a result, Fe(II) is released into the environment, rather than into the cell. This can be the starting point for microbial interactions [2]. In our study, we are interested in a putative mutualism between the photoreactive siderophoreproducing bacterium Cupriavidus necator H16 [3] and the diatom Navicula pelliculosa, which exchange iron for carbon. If N. pelliculosa indeed profits from increased iron supply by the siderophore, we could expect the alga to produce metabolites that further stimulate siderophore production. In order to test this hypothesis, we constructed a siderophore reporter strain using lacZ as reporter gene. In the ß-galactosidase assay we now investigate, how algal exudates influence siderophore production by C. necator H16. [1] Sandy, M., and Butler, A. (2009). Microbial iron acquisition: marine and terrestrial siderophores. Chemical reviews , 109 (10), 4580-4595. [2] Amin, S. A., Green, D. H., Hart, M. C., Küpper, F. C., Sunda, W. G., and Carrano, C. J. (2009). Photolysis of iron-siderophore chelates promotes bacterial-algal mutualism. Proceedings of the National Academy of Sciences, 106 (40), 17071-17076. [3] Kreutzer, M. F., Kage, H., and Nett, M. (2012). Structure and biosynthetic assembly of cupriachelin, a photoreactive siderophore from the bioplastic producer Cupriavidus necator H16. Journal of the American Chemical Society, 134 (11), 5415-5422.

Bacterial Natural Products Involved in Soft Rot of White Button Mushrooms Tawatchai Thongkongkaew, Evgeni Bratovanov, María García-Altares, Kirstin Scherlach, Christian Hertweck Leibniz Institute of Natural Product and Infection Biology, HKI, Jena, Germany. Friedrich Schiller University, Jena, Germany The white button mushroom Agaricus bisporus is one of the most popular edible mushrooms throughout the world. To ensure good mushroom quality, the farmers have to control the culture conditions carefully to prevent crop losses due to bacterial infections. One infamous pathogen is Burkholderia gladioli pv. agaricicola, which causes soft rot symptoms on the mushroom caps [1]. The disease develops very quickly and can lead to a complete loss of the harvest in a short time. Previous studies suggested that digestive enzymes and toxins play a role during mushroom infection. Whereas the involvement of enzymes has been reported earlier [2], hardly anything was known about the role of bacterial toxins. Here we report the MALDI-MS imaging guided discovery and structure elucidation of a bacterial virulence factor and two novel lipopeptides that are indirectly involved in the infection process. By genome mining and targeted knockout experiments the molecular

POSTERS - CHEMICAL ECOLOGY basis of the biosynthesis of the novel compounds was identified. MS-based imaging of the infected mushroom caps, swarming assays and infection studies with deletion mutants clarified the functional role of the various metabolites in the mushroom disease. Our work not only provides the basis for future crop protection measures, but also further illustrates how imaging MS can guide the discovery of novel bioactive molecules. [1] Gill, W.M., Cole, A.L.J. (1992). Cavity disease of Agaricus bitorguis caused by Pseudomonas cepacia. Can J. Microbiol. 38, 394-397 [2] Chowdhury, P.R., Heinemann, J. (2006). The general secretory pathway of Burkholderia gladioli pv. agaricicola BG164R is necessary for cavity disease in white button mushroom. Appl. Environ. Microbiol. 72, 3558-3565

Identification and characterization of an Arabidopsis mutant impaired in calcium signaling Johannes Thürich [1], Lothar Altschmied [2], Elena Petutschnig [3], Ralf Oelmüller [1] [1] Institute for Plant Physiology, Faculty of Biology and Pharmacy, University of Jena, Jena, Germany [2] Service Team, Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany [3] Albrecht-von-Haller-Institute for plant research, Dep. Plant Cell Biology, University of Göttingen, Göttingen, Germany Pirifomospora indica is a beneficial fungus which was isolated from the Indian Thar desert. It has two lifestyles. It can live as a saprophyte in the soil or can form an endophytic interaction with many different plant species including Arabidopsis thaliana . Thus it has become a model organism to study symbiotic interaction. Plants which get colonized by the fungi show an increased growth and higher resistance towards biotic stress such as pathogens or abiotic stress such as drought. We are interested in the early steps of plant-fungus interaction. It was shown that P. indica induces an elevation of cytosolic calcium in A. thaliana plants shortly after contact. Furthermore our group was able to identify the cell wall compound which is responsible for this spike in calcium response. This effector, a trisaccharide, might be a new MAMP (molecular associated molecular patterns) or DAMP (damage associated molecular patterns). In the next step we were interested to identify the plant molecule which is responsible to recognize the elicitor of P. indica. Thus we generated an Arabidopsis EMS (Ethyl methanesulfonate) mutant which does not show the calcium elevation after exposure with the afore-mentioned trisaccharide. In order to determine and confirm the identity of the molecular basics of this mutant we employed several molecular techniques including next generation sequencing. Contrary to our expectations, we didn’t find a receptor but a key regulator of RNA stability and epigenetical regu-

lation. These finding will allow us to study new aspects of the plant-fungus interaction. Interactions between Chlamydomonas reinhardtii and other microorganisms Daniel Schaeme, Prasad Aiyar, Maria Mittag, Severin Sasso Institute of General Botany and Plant Physiology, Friedrich Schiller University, Jena, Germany While several associations between land plants and microorganisms are relatively well characterized, little is known about the interactions between microalgae and other microorganisms [1]. To investigate how microalgal-microbial interactions shape microbial communities and impact biogeochemical processes, we have started to study the interactions of Chlamydomonas reinhardtii with various other microorganisms that live in soil and fresh water. When the growth rates of C. reinhardtii were quantified in axenic culture and in mixed cultures with different bacteria, a variety of interactions were identified ranging from beneficial to detrimental. To elucidate the role of secondary metabolites in these interplays, the profiles of intracellular and extracellular metabolites were compared between axenic cultures and mixed cultures using liquid chromatography-mass spectrometry (LC-MS). Results of ongoing experiments will be presented, and their environmental implications will be discussed. [1] Hom, E. F., Aiyar, P., Schaeme, D., Mittag, M., & Sasso, S. (2015), A chemical perspective on microalgal-microbial interactions. Trends Plant Sci. 20, 689-693.

Effect of bacteria on growth and mating of the benthic diatom Seminavis robusta: a metabolomic approach Emilio Cirri, Georg Pohnert Institute for Inorganic and Analytical Chemistry, Bioorganic Analytics, Friedrich Schiller University, Jena, Germany Diatoms are important microalgae that shape marine environments and contribute to more than 20% of primary production. Signal molecules mediate their life cycle and mating, but only recently the first diatom pheromone was identified in the benthic diatom Seminavis robusta. Diproline (proline derived diketopiperazine) drives the chemoattraction of the mating partners [1]. Since the natural biofilm-environment of benthic diatoms is very complex, we hypothesize that other organisms might interfere with their chemical communication. We studied the pheromone chemistry and behavioral response of S. robusta both in presence and absence of bacteria. Bioassays with different bacterial strains, target analysis (using GC/LC-MS) to check the production and degradation of diproline,

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and an untargeted metabolomics approach were to comprehensively characterize the interaction. We found that different bacteria have different effects on the mating and the growth of S. robusta, as well as on the production of diproline, which is always higher in axenic conditions. Comparative untargeted metabolomics allowed us to highlight some molecules that were upregulated in presence or absence of bacteria, such as amino acids and fatty acids, that could be used by bacteria as nutrients. [1] Gillard et al., Angewandte Chemie International Edition, 2013

Triacylglycerols and polar lipids fuel the wound activated oxylipin production of the moss Dicranum scoparium Daniel Stettin, Verena Jeschke, Georg Pohnert Friedrich-Schiller-University Jena Oxylipins, the products of oxidative transformation of polyunsaturated fatty acids play central roles in the development and chemical defense or plants. In particular mosses have attracted attention due to their unusual oxylipin chemistry and novel modes of actions of these metabolites. We address here the regulation of oxylipin-production of Dicranum scoparium. This moss uses highly unusual acetylenic fatty acids as well as common polyunsaturated fatty acids for oxylipin production. Using a targeted analysis of galactolipids as well as a lipidomic approach we could show that wounding of the moss induces both, the release of polyunsaturated fatty acids from galactolipids, thereby following a well known activation mechanism from higher plants. In contrast, the formation of acetylenic oxylipins is initiated by enzymatic lysis of triacylglycerols. This unusual bimodal release of precursors for oxylipin production illustrates how mosses have evolved both, known and novel pathways towards the physiologically and ecologically important oxylipins. The role of bacterial volatiles in the long-distance microbial interspecific interactions Adam Ossowicki [1,2], Sylwia Jafra [2], Paolina Garbeva [1] [1] Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands [2] Laboratory of Biological Plant Protection, Department of Biotechnology, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, Gdansk, Poland Secondary metabolites play important role in plantmicrobe and microbe-microbe interactions e.g. as signalling compounds (communication) or as suppressive agents (interference competition). One group of secondary metabolites produced by soil

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and plant-associated microorganisms but largely unexplored to date, are the volatile organic compounds (VOCs). VOCs are typically small compounds with low molecular mass, high vapour pressure, low boiling point and often lipophilic moiety. These properties facilitate evaporation and diffusion through both water- and gas-filled pores in soil and rhizosphere environments. Here we will present several examples revealing the importance of bacterial VOCs for the long-distance interspecific microbial interactions. Particular attention will be given to VOCs emitted by rhizobacteria and their effect on the plant pathogenic fungi, oomycete and bacteria. Furthermore, we will report on the involvement of the GacS/GacA twocomponent regulatory system for bacterial VOCs production. Hence, bacterial VOCs are not just a metabolic waste but compounds with biological activities and with relevance for the producing organism in its ecological context. Survey of allelopathic interactions in phytoplankton Lydia A. Papanikolopoulou [1], Franziska Speck [1], Colomban de Vargas [2], Ian Probert [2], Georg Pohnert [1] [1] Friedrich Schiller University Jena, Institute of Inorganic and Analytical Chemistry, Jena, Germany [2] CNRS, UMR 7144, Station Biologique de Roscoff, Roscoff, France In the open waters of oceans and lakes we observe a plethora of coexisting phytoplankton species. Species abundance is in contradiction with the principle of competitive exclusion, which dictates that the number of coexisting species cannot exceed the number of the limiting resources (Gause, 1932). To understand which mechanisms and to what extend they contribute to the aforementioned paradox - known as the paradox of the plankton - many studies have suggested “allelopathy” as the leading cause. Even though many studies have focused on phytoplankton allelopathy, most of them are restricted to the interaction of only two species - usually involving toxic ones. Our knowledge is thus limited if types and prevalence of interactions in natural in phytoplankton assemblages is concerned. In the present study we used the Roscoff Culture Collection to survey the relationship of different phytoplankton species combinations. By co-culturing 37 combinations of 19 species, we observed positive, negative or neutral interactions. Interestingly no universal positive or negative allelopathy of single species was observed, but rather combinationdependent effects manifested during co-culturing. Gause, G.F. 1932.The Struggle for Existence. Mineola, NY: Dover Publications.

POSTERS - CHEMICAL ECOLOGY gates („iron snow"). Appl. Environ. Microbiol. 79, 4272-4281.

Chemical communication between iron oxidizing and iron reducing bacteria in iron snow Qianqian Li [1], Jiro F. Mori [1], Carl-Eric Wegner [1], Rebecca E. Cooper [1], Kirsten Küsel [1,2] [1] Institute of Ecology, Friedrich Schiller University Jena, Germany [2] The German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany Iron-rich pelagic aggregates (iron snow) are formed in the water column through adsorption of inorganic and organic matter and colonization of motile microorganisms. Iron snow represents a local hot spot for microbial interactions. These include cell-to-cell contact, feeding, but also intercellular communication via diffusive chemical signals [1]. Iron snow bacterial communities are dominated by iron cycling bacteria, including Fereducing (FeRB) and Fe-oxidizing (FeOB) bacteria [2]. In the current study, we aim to elucidate potential chemical interactions between FeOB and FeRB within iron snow. Dominant microorganisms comprising iron snow aggregates, including Acidithrix C25, an FeOB, Acidiphilium C61, an FeRB, and Acidocella C78, another FeRB, were isolated to study interspecies chemical cross-talk. Additional Acidiphilium strains (JF-5, SJH) were investigated as well. Cell-free supernatant exchange experiments and metabolomics profiling were used to identify potential signaling molecules. Previous experiments, targeting Acidithrix C25 and Acidiphilium C61, led to the identification of the aggregationinducing signaling molecule, 2-phenethylamine (PEA) via comparative metabolomics. Fluorescence microscopy showed that PEA produced by Acidithrix C25 induces aggregate formation by Acidiphilium C61[1]. In the current study, we showed that PEA cannot trigger a loss of motility in both Acidocella C78 and Acidiphilium SJH, but motility is reduced for Acidiphilium JF-5. Interestingly, we observed an increased rate of Fe(II) oxidation when Acidithrix C25 pure cultures were supplemented with Acidocella C78 cell-free supernatant. This finding suggests additional chemical mediators, which ultimately modulate aspects of metabolism beyond motility. Future work involves transcriptomics-, genomics- and metabolomicsbased strategies to deepen our understanding of intercellular communication and metabolic modulating among microbes in iron snow. [1] Mori, J.F., Ueberschaar N., Lu, S., Cooper R. E., Pohnert, G. & Küsel, K. (2017). Sticking together: Inter-species aggregation of bacteria isolated from iron snow is controlled by chemical signaling. ISME. [2] Lu, S., Chourey, K., Reiche, M., Nietzsche, S., Shah, M. B., Neu, T. R., Hettich, R. L. & Küsel, K. (2013). Insights into the structure and metabolic function of microbes that shape pelagic iron-rich aggre-

Interactions of Rhizobacteria in Legume-Cereal Intercropping System Siddhi Vora, Mugdha Kulkarni, Gattupalli Archana Department of Microbiology & Biotechnology Centre, The Maharaja Sayajirao University of Baroda, India Legume-cereal intercropping has been widely studied in the context of diversity, ecosystem function and high yield [1]. Plant growth promoting rhizobacteria (PGPR) are the soil bacteria inhabiting zone around/on the root surface and are directly or indirectly involved in promoting plant growth. Diverse symbiotic and non-symbiotic rhizobacteria are being used worldwide as bioinoculants to promote plant growth and development in monoculture plants [2]. However, their interactions in Legume-cereal intercropping system are less known. The present study highlights microbial interactions of different genera of non symbiotic (Pseudomonas sp. G22, Enterobacter sp. C1D) and symbiotic (Bradyrhizobium sp. IC3109) PGPR with plants grown in Legume (C. cajan) - Cereal (Z. mays) intercropping system. These strains showed microbial exchange and colonisation on roots from inoculated to uninoculated plant systems (C. cajan - Z. mays) grown in sand culture. One of the plausible hypothesis for their exchange is root exudates that drive the bacteria towards plant roots. Root exudates of the intercrop and monocrop plants were analysed for differential response of the various genera by studying growth pattern, biofilm formation, chemotaxis capillary, swarm and swim plate assays [3]. Thus, the interaction between these rhizobacteria and root exudates components of monocrops and intercrop may contribute in understanding the mechanisms relevant to application of PGPR strains for agricultural production in legume-cereal intercropping system. [1] Lithourgidis, A. S., Dordas, C. A., Damalas, C. A., Vlachostergios, D. (2011). Annual intercrops: an alternative pathway for sustainable agriculture. Australian journal of crop science, 5(4), 396. [2] Ahemad, M., Kibret, M. (2014). Mechanisms and applications of plant growth promoting rhizobacteria: Current perspective. Journal of King Saud University-Science, 26(1), 1-20. [3] Yuan, J., Zhang, N., Huang, Q., Raza, W., Li, R., Vivanco, J. M., Shen, Q. (2015). Organic acids from root exudates of banana help root colonization of PGPR strain Bacillus amyloliquefaciens NJN-6. Scientific reports, 5.

What triggers transcriptional regulation of organohalide respiration in Sulfurospirillum ssp.? Jens Esken, Tobias Goris, Torsten Schubert, Gabriele Diekert Dept. of Applied and Ecological Microbiology, University of Jena, Jena, Germany

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Sulfurospirillum multivorans performs organohalide respiration (OHR). The key enzyme is the tetrachloroethene (PCE) reductive dehalogenase (PceA), an iron sulfur protein with a cobamide cofactor (norpseudo-B12 ). The gene encoding PceA is located in close vicinity to a gene cluster for cobamide biosynthesis. The gene expression of pceA is induced by PCE. In the absence of PCE the transcription ceased over more than 100 generations. This observation raised the question for the signal, which drives gene expression while PCE is absent. Since the formation of catalytically active enzyme is strictly dependent on the presence of cobamide, the role of the cofactor and the cobalt positioned in its center in the regulation of OHR was investigated. Sulfurospirillum multivorans was repeatedly sub-cultivated with nitrate rather than PCE as electron acceptor, while the type of cobamide cofactor was manipulated by guided biosynthesis. The isolates were also cultivated under cobalt limitation. The amount of PceA, the enzyme activity, the substrate conversion, and the transcript of the pceA gene was monitored. In addition, the level of cobamide cofactor in the cells was measured as well as the level of transcript of the cobamide biosynthesis genes. Changes in the structure of the cofactor, which led to inactive PceA, had no effect on the long-term down-regulation of the OHR. The catalytically active form of PceA does not trigger the regulation of OHR gene expression. From variations in cobalt supply a decrease in the amount of cobamide in the cells was observed. Limitations in cobalt supply affected PceA activity and the level of transcript was changed under these conditions. This allowed for conclusions on the role of the enzyme’s cofactor in regulation. Furthermore, novel insights into the general role of cobalt in global gene regulation are envisaged. Hunting strategies of the soil amoeba Protostelium mycophaga on the fungal pathogen Aspergillus fumigatus Iuliia Viediernikova, Falk Hillmann Junior Research Group Evolution of Microbial Interaction, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Jena, Germany The Aspergilli are ubiquitous saprophytic filamentous fungi which cause fatal infections in immunocompromised individuals. Of these, the highest incidences and mortality rates are reported for Aspergillus fumigatus. The absence of any highly specific virulence factors suggest that a number of general fungal virulence determinants act in concert to escape to colonize the host and escape innate immune cells. Considering the natural habitat of such molds, it is plausible that such attributes

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have emerged long before the appearance of innate immune systems of infected vertebrates and may have helped to survive predatory pressure. The amoebozoa represent one of the largest and most diverse group among the protozoa, but all share a predatory life-style. In the past, we have analyzed the physical and chemical interactions of the model amoeba Dictyostelium discoideum with A. fumigatus. Although the surface of A. fumigatus reduced amoeba recognition, D. discoideum was to ingest conidia and initiate its phagolysosomal pathway. However, killing of A. fumigatus conidia was not observed. Here, we have studied the antagonistic interactions of the filamentous fungus Aspergillus fumigatus with the widely spread fungivorous amoeba Protostelium mycophaga. During in vitro confrontation, the surface composition of the fungus was demonstrated to play a major role. While dormant conidia appeared to be inert and were not ingested by P. mycophaga, this drastically changed after germination. Once the protective layer of rodlet proteins and DHN melanin was lost exposed polysaccharides resulted in enhanced amoeba’s assault on exposed fungal germlings and hyphae. Surprisingly, phagocytosis was not required to kill and feed on the hyphae. Our current data support the idea that protozoan predation on fungi occurs globally and could have promoted the development of defence mechanisms which could also affect virulence in higher organisms.

Natural products Superbug of nosocomial infection methicillinresistant Staphylococcus aureus (MRSA) and recent trends in antibiotic susceptibility pattern Kiran Fatima Shaheed Zulfikar Ali Bhutto Institute of Science and Technology, Karachi, Pakistan Background: MRSA is an emerging pathogen in skin and soft tissues and most common cause of nosocomial infections. It is gaining resistance to available drugs rapidly which is alarming for medical workers and researchers. Material/methods: A total of 3022 samples from various anatomical sites of patients were analyzed for MRSA and 14% of these were positive for MRSA. Identification and antimicrobial sensitivity testing was performed using the CLSI 2015 guidelines. Quality is ensured by using the quality strain of S. aureus (ATCCR 29213). Most commonly recommended drugs were used for susceptibility testing with standard potency. Results: MRSA is resistant to most of the drugs prescribed for the Gram-positive infections. It is rapidly gaining resistance against aminoglycosides, macrolides, DO and SXT. The drugs available for treatment of infection caused by MRSA include

POSTERS - NATURAL PRODUCTS Clindamycin, Linezolid and Vancomycin. Resistance to vancomycin is being reported throughout the world but in our study none of these were resistant. Conclusions: There is the need for discovery of new antibacterial drugs or modification of existing drug to make them more effective and to initiate awareness programs about excessive and misuse of antibiotics. There should be some rule and regulation for empirical therapy after admission to hospital and before or after surgery. Key words: MRSA, Antibiotics resistance, Vancomycin, Linezolid, Clindamycin Discovery of eukaryotic cryptic natural products by heterologous expression Jun Lin [1], Maria Stroe [2], Sandra Hoefgen [1], Derek J. Mattern [2], Huijuan Guo [3], Axel A. Brakhage [2], Christine Beemelmanns [3], Vito Valiante [1] [1] Leibniz Research Group – Biobricks of Microbial Natural Product Syntheses [2] Department of Molecular and Applied Microbiology [3] Research Group – Chemical Biology of Microbe-Host Interactions, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Adolf-ReichweinStr.23, 07745 Jena, Germany Filamentous fungi surfaced as a treasure-trove for secondary metabolites mining. We can already access hundreds of fungal draft genome sequences, which provide abundant information about unknown biosynthetic genes encoding potentially valuable natural products [1]. However, potential biosynthetic gene clusters are hardly activated under normal culture conditions, making the discovery rate limited [2]. The increased knowledge about biosynthetic gene clusters promotes the development of tools aimed to accelerate the discovery process, such as heterologous expression of entire biosynthesis pathways. To satisfy this demand, we developed an efficient but convenient system based on the polycistronic expression of gene clusters in filamentous fungi [3]. This method was successfully tested to complement austinoid production in Aspergillus nidulans by expressing four genes isolated from Aspergillus calidoustus, including a large gene coding for a non-iterative polyketide synthase. A quick selection system for selecting positive mutant strains permitted easily finding and isolating compounds of interest. This tool is currently applied to explore unknown secondary metabolic gene clusters predicted from fungal genomic databases.

[3] Unkles, S. E., Valiante, V., Mattern, D. J., & Brakhage, A. A. (2014). Synthetic biology tools for bioprospecting of natural products in eukaryotes. Chem Biol, 21(4), 502-508.

Streptomyces iranensis genetic manipulation paves the way for identification of the eliciting agent of gene cluster activation in Aspergillus nidulans Mario Karl Claude Krespach [1,3], Tina Netzker [1,3], Volker Schroeckh [1], Kirstin Scherlach [2], Christian Hertweck [2,3], Axel A. Brakhage [1,3] [1] Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany. [2] Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany. [3] Friedrich Schiller University, Jena, Germany. Streptomycetes, soil-dwelling Gram-positive bacteria, are well-known producers of a multitude of secondary metabolites. S. iranensis HM 35, which is closely related to S. rapamycinicus, is a rapamycin producer and can specifically induce the formation of natural products in filamentous fungi, such as A. nidulans and the human pathogenic fungus A. fumigatus. To identify the primary bacterial signal, genetic manipulation of S. iranensis is essential. Therefore, a modified protocol for gene deletion of S. iranensis was developed. On the poster, the successful application of the method is demonstrated by deletion of hutF, a gene involved in histidine degradation and of azlA, coding for a putative polyketide synthase in the putative azalomycin F biosynthesis gene cluster. As an outlook, a transposon-based strategy for the identification of genes, involved in A. nidulans orsellinic acid (ors) gene cluster activation, is described. [1] Hamedi J et al . (2010). Int J Syst Evol Microbiol. 60: 1504–1509. [2] Horn F et al . (2014). Genome Announc. 2(4): e00616-14. 3) Schroeckh V et al . (2009). PNAS. 106: 14558-14563. [4] Brakhage AA (2013). Nat Rev Microbiol. 11: 21-32. [5] König CC et al . (2013). ChemBioChem. 14: 938-942. [6] Netzker T et al . (2016). Appl Environ Microbiol. 82: 3481–3492. [7] Magasanik B and Bowser H (1955). J Biol Chem. 213(2): 571-580. [8] Bilyk B et al . (2013). Appl Microbiol Biotechnol. 97(1), 351-359.

[1] Fischbach, M. A., & Walsh, C. T. (2009). Antibiotics for emerging pathogens. Science, 325(5944), 1089-1093.

A Bioactive Compound Effective Against Candida albicans from Syncephalastrum Species Alemayehu Amare [1], Dawit Abate [2] [1] Adama Science & Technology University, Adama, Ethiopia [2] Addis Ababa University, Addis Ababa, Ethiopia

[2] Mattern, D. J., Valiante, V., Unkles, S. E., & Brakhage, A. A. (2015). Synthetic biology of fungal natural products. Front Microbiol, 6, 775.

Due to the emerging prevalence of drug resistant strains of Candida albicans, there is an exigent need

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for novel antifungal remedies and fungi remain a vital source of antibiotics. Synencephalastrum sp. (AFC003) is a soil fungus which was isolated from litter associated with Afrocarpus falcatus (Zigba) trees and was investigated for the production of secondary metabolites on sterile moist rice. The sterilized moist rice was inoculated with young blocks of agar (10mm2 ) of the fungus culture and was harvested just after 28 days. The dried and finely ground moldy rice was extracted with only ethyl acetate using Rota- vapor. The crude extract was tested in vitro for activity against C. albicans and showed an inhibition diameter of 16mm. C. albicans is a dimorphic fungus which belongs to the normal microflora of the human gastrointestinal tract. C. albicans causes thrush and is prevalent in 64-84% of HIV-infected patients and in 28% of HIV-negative persons. The crude extract was further purified via successive bioassays. Accordingly, the purified compound was separated with 1:8 solution of hexane: ethyl acetate. The bioactive fraction detected by TLC had a single band with Rf value of 0.53 when visualized under U.V. (254 and 366nm). The purified active compound (10μg/ml) also showed an inhibition diameter of 9mm against C. albicans and was compared with the positive control (ketoconazole, 10μg/ml) and the negative control (hexane, 10μg/ml). MIC of the potent compound was determined via broth microdilution method. MIC was defined as the lowest concentration of the substance that had no visible turbidity. The MIC break point was ranging from 80μg/ml to 100μg/ml. Taxonomy of the compound producing fungus was preliminarily identified to belong to the genus Synencephalastrum and is subject to molecular characterization. Further analysis of the purified compound with HPLC and NMR will reveal its peak and its chemical structure respectively. Discovery of new antifungal compounds from the social amoeba Dictyostelium discoideum Tom Lauterbach [1], Silvia Novohradská [1], Matthias Steinacker [2], Falk Hillmann [1] [1] Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Evolution of Microbial Interactions, Jena, Germany [2] Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Bio Pilot Plant, Jena, Germany Aspergillus fumigatus acts as an opportunistic human pathogen which can cause infections in immunocompromised patients and will often result in fatal invasive aspergillosis. Furthermore the therapy of systemic fungal infections with antifungal agents is limited to only a small number of active compounds with their therapeutic potential being

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further diminished by the increasing numbers in resistant strains. In its natural environment A. fumigatus is a ubiquitious, filamentous ascomycete that is known for its saprophytic lifestyle and is exposed to numerous other microorganism such as natural competitors and predators. We have previously shown that the model amoeba Dictyostelium discoideum is able to ingest fungal conidia. The ingested conidia entered the phagolysosomal pathway, but remained viable. Intracellular germination occurred only after longer incubation, similar as observed earlier with macrophages. Even though D. discoideum was unable to digest or kill the fungal conidia we observed that the presence of amoeba inhibited germination of extracellular conidia. The unknown compound was retained in culture supernatants of axenic cultures of D. discoideum and activity was seen against various species among Aspergilli. We are currently studying the chemical basis of this inhibitory activity through a bioactivity guided assay using extracts of axenic cultures of D. discoideum . As the unknown compound remained stable following heatand proteinase K treatment, we expect a natural product to be produced by the amoeba, which is responsible for the antifungal activity. We are aiming to isolate this compound, elucidate its structure and further characterize its antifungal properties. Pattern recognition methods for prediction of chemical structures of fungal secondary metabolites Sagar Gore, Ekaterina Shelest Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Jena, Germany In many bacterial and fungal species, secondary metabolites (SMs) are produced as a part of defense mechanisms against co-localizing microorganisms or to strengthen symbiotic relationships with their hosts. Non-Ribosomal Peptide Synthetases (NRPS) and Polyketide Synthases (PKS) pathways are two major pathways for their biosynthesis. Genome mining efforts have suggested many SM pathway gene clusters (genes producing SMs are grouped together) in fungi without any knowledge about SMs produced by them [1]. NRPS pathway genes are organized into various modules that work like assembly line catalyzing different enzymatic reactions building complete SM. NRPS adenylation (A) domains are involved in specific substrate binding and their activation by ATP dependent adenylation. A domains are known to recognize multitudes of substrates - around 530 are known [2]. Currently available tools for A domain substrate specificity prediction work well with bacterial sequences but predictions for fungal sequences still needs an im-

POSTERS - NATURAL PRODUCTS provement [3, 4]. To achieve this goal to improve fungal specificity predictions, here NRPS substrate structures were analyzed to find their similarities/differences to each other. Also NRPS codes - 10 and 34 residues that form the substrate binding site for characterized NRPS domains were clustered. Our preliminary results show that some substrates that are similar to each other have similar binding sites irrespective of their origin (bacterial or fungal) while for other substrates binding sites vary. Thus these fungal and bacterial substrate binding preferences would be taken into consideration and a tool for fungal substrate specificity prediction would be developed. This tool should be useful in prediction of complete SM structures based on their monomer specificities. Predictions of SMs structures from gene cluster sequences would be very useful to produce tailor made novel SMs of pharmaceutical importance. [1] Inglis, Diane O., et al. „Comprehensive annotation of secondary metabolite biosynthetic genes and gene clusters of Aspergillus nidulans, A. fumigatus, A. niger and A. oryzae." BMC microbiology 13.1 (2013): 1. [2] Caboche, Ségolène, et al. „NORINE: a database of nonribosomal peptides." Nucleic acids research 36.suppl 1 (2008): D326-D331. [3] Röttig, Marc, et al. „NRPSpredictor2-a web server for predicting NRPS adenylation domain specificity." Nucleic acids research (2011): gkr323. [4] Baranaši´c, Damir, et al. „Predicting substrate specificity of adenylation domains of nonribosomal peptide synthetases and other protein properties by latent semantic indexing." Journal of industrial microbiology - biotechnology 41.2 (2014): 461-467.

Actinomycetes and yeasts from a heavy metal contaminated site Benjamin Funai [1], Karin Martin [2], Katrin Krause [1], Martin Roth [2], Erika Kothe [1] [1] Friedrich Schiller University, Institute for Microbiology, Microbial Communication, Jena, Germany [2] Leibniz Institute for Natural Compound Research and Infection Biology – Hans-Knöll-Institute, Jena, Germany The test site Gessenwiese near Ronneburg (Germany), a former uranium mining area, represents an extreme habitat with low pH, high salt concentrations and bioavailable heavy metal ions. To study the application of plants and microbes in bioremediation of heavy metal polluted areas, field scale experiments are performed there. At this location, we isolated especially actinomycetes and yeasts from the rhizosphere, phyllosphere and bulk soil. The isolation of rare actinomycetes and yeasts or even the screening of already known strains under novel conditions for bioactive metabolites might improve the strategies in the research on drug discovery as a result of the adaptation to unfavorable soil conditions. Actinomycetes, as

well as yeasts, are well-known for their ability to produce a wide range of bioactive secondary metabolites. In our actinomycete and yeast isolates, we see the potential for application to bioremediation of polluted sites, to study distribution of environmental resistances and sources for new drugs. Of about 300 isolates, antimicrobial activities and plant growth promoting features including nitrogen fixation, phosphate mobilization, phytohormone and siderophore production, as well as heavy metal resistance were screened. A number of isolates showed the potential to act as plant growth promoting microorganisms by phosphate and iron mobilization and the production of antibiotics and auxins. The activation of genes for new metabolites can be facilitated through stress like heavy metals or signal molecules in co-cultivation. Experiments including actinomycetes and yeasts in co-cultivation as well as extracts of heavy metal treated liquid cultures showed in some isolates an induced production of bioactive substances in contrast to pure cultures or extracts of untreated cultures. Morphological evaluation and antimicrobial activity of terrestrial cyanobacterial strains from agricultural lands of Kermanshah province, Iran Sara Abbasi [1], Javad Hamedi [2,3], Bahareh Nowruzi [4] [1] Department of Microbiology, Faculty of Advanced Sciences & Technology, Pharmaceutical Sciences Branch, Islamic Azad University, Tehran, Iran [2] Department of Microbial Biotechnology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Iran [3] Microbial Technology and Products Research Center, University of Tehran, Iran [4] Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran Secondary metabolites from cyanobacteria have toxic, hormonal, antineoplastic and antimicrobial activities. Recently, there has been an increasing interest in cyanobacteria as a high potential source for new drugs. The objective of the present study was to adapt, develop and apply bacterial and fungal bioassays for the observation and quantification of possible antimicrobial effects from methanolic extracts of cyanobacteria. Therefore, 53 cyanobacterial that were isolated from various soil samples of Kermanshah province, were studied for their antimicrobial activities. The results showed that 8 isolates belong to unicellular and heterocystous branched cyanobacteria had antimicrobial activity. Maximum antimicrobial activity was seen in Fischerella sp. and Chroococcus sp.. Fischerella sp. was the only strain that showed good activ-

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ity against Staphylococcus aureus and Candida albicans. However, no inhibitory effect was found against Aspergillus niger and Pseudomonas aeruginosa. But, Chroococcus sp. showed high inhibitory effects against Pseudomonas aeruginosa. The molecular identification of two strains with the highest antibacterial activity was done for amplification of 16S rRNA gene and the sequences registered under DDBJ. This work showed the potential of cyanobacteria from Iran as a good source of antibiotics. Adaptation of the filamentous fungus Aspergillus nidulans to low temperature stress Benjamin Hanf [1], Thomas Krüger [1], Boyke Bunk [2], Derek Mattern [1], Jörg Overmann [2], Olaf Kniemeyer [1,3], Axel A. Brakhage [1,3] [1] Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute, Molecular and Applied Microbiology, Jena [2] Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig 3Friedrich Schiller University, Department of Microbiology and Molecular Biology, Institute of Microbiology, Jena [3] Friedrich Schiller University, Department of Microbiology and Molecular Biology, Institute of Microbiology, Jena Natural products serve as mediators of biological communication and as a valuable source for pharmacologically relevant components. The genes involved in the production of these compounds are usually organized in clusters. To elucidate the variety of natural compounds produced by an organism, different stress factors can be applied to induce silent gene clusters. Fungi naturally encounter sharp temperature shifts in their environment. To explore the range of bioactive compounds formed at low temperature stress we investigated the transcriptome and proteome profile of A. nidulans at 10 and 37 ◦ C. As a response to low temperature stress, genes involved in the categories of cold stress protection, cell development and biosynthesis of natural products were up-regulated. These findings were confirmed on the protein level via a comparative gel-based (DIGE) and gel-free (LCMS/MS) proteomic approaches . Moreover, the specific formation of natural products at low temperature was confirmed at the metabolite level by LC-MS/MS. Our analyses revealed on genetic and protein level the induction of factors, which regulate the sexual cycle in A. nidulans. On metabolic level the sporogenic factor PsiA was found, which regulates the spore balance between asexual and sexual spore development. In addition, some of the identified secondary metabolites like asperfuranone have been reported to trigger morphological differentiation and to exhibit anti-proliferative activity. Further activated secondary metabolite gene

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clusters have unknown functions. Experiments for the characterisation of the biological role of these cryptic gene clusters are on-going. In summary, our study demonstrates that low temperature stress induces the production of a variety of secondary metabolites in A. nidulans and represents a strategy to exploit the potential of filamentous fungi as sources of secondary metabolites. Silent gene cluster characterisation in Aspergillus fumigatus Maria C. Stroe [1,2], Tina Netzker [1,2], Vito Valiante [1,3], Axel A. Brakhage [1,2] [1] Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Jena, Germany [2] Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany [3] Research Group Biobricks of Microbial Natural Product Synthetases, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Jena, Germany The human pathogenic fungus Aspergillus fumigatus has a high capacity to synthesise natural products. More than 30 biosynthetic gene clusters are predicted in its genome, yet some appear to be silent, and thus their respective products remain elusive. Since many fungal compounds show significant biological activity, we are motivated to discover new products with novel interesting functions. The cluster presented here was identified through genome mining and is one of the remaining uncharacterized clusters in A. fumigatus. The biosynthetic pathway was studied heterologously, and characterization of the cluster in its native host provided insight into its regulation. Cyanobacterial metabolites with inter-species communication functions Tomasz Chilczuk, Timo Niedermeyer Interfaculty Institute of Microbiology and Infection Medicine (IMIT), University of Tübingen, Tübingen, Germany The excessive use and misuse of antibiotics resulted in the emergence of multiple drug resistant strains. Even though there is a growing need for new classes of antibiotics, the development is lagging far behind the demand [1]. The inhibition of quorum sensing (QS) systems in pathogenic bacteria has been discussed as a new promising strategy for anti-virulence therapy, since many pathogenic bacteria use quorum sensing to regulate the expression of virulence factors or the formation of biofilms [2]. Although cyanobacteria have gained

POSTERS - SYSTEMS BIOLOGY much attention as a prolific source for novel bioactive compounds [3], little is known about QS active metabolites. Until now only few compounds have been reported from cyanobacteria that disrupt AHL-like QS systems. In comparison, no studies were made regarding QS active metabolites from cyanobacteria targeting non-AHL like QS systems found in pathogens like Staphylococcus aureus. Based on this shortfall we want to identify and characterize new QS active metabolites from cyanobacteria as well as their targets in the QS systems of other bacteria. Therefore, we screened our collection of 570 cyanobacteria extracts with several monitor strains covering all major known QS systems. Bioactivity-guided fractionation with various chromatographic techniques has been performed in order to isolate QS active metabolites. Promising compounds will be further characterized using HPLC coupled with mass spectrometry followed by structure elucidation using nuclear magnetic resonance spectroscopy and tandem mass spectrometry. Preliminary screening results show that some cyanobacterial extracts show quorum sensing inhibition, quorum sensing enhancing and antibacterial activities against our biosensor strains. By isolating new QS active metabolites we are able to give access to novel natural compounds, which can be lead structures for the development of antivirulence drugs. [1] O’Connell, K.M., et al., Combating Multidrug-Resistant Bacteria: Current Strategies for the Discovery of Novel Antibacterials. Angewandte Chemie International Edition, 2013. 52 (41): p. 1070610733. [2] Rampioni, G., L. Leoni, and P. Williams, The art of antibacterial warfare: Deception through interference with quorum sensingmediated communication. Bioorg Chem, 2014. 55: p. 60-8. [3] Niedermeyer, T.H., Anti-infective Natural Products from Cyanobacteria. Planta Med, 2015. 81 (15): p. 1309-25.

Development of droplet microfluidic platform with integrated optical fibers for microbial screening Sundar Hengoju, Miguel Tovar, Thomas Weber, Lisa Mahler, Mahipal Choudhary, Oksana Shvydkiv, Martin Roth Leibniz Institute for Natural Product Research and Infection Biology, - Hans Knöll Institute – Jena A rapid and cost-effective microbial screening procedure is required for the discovery of novel natural products. Droplet-based microfluidics is a highthroughput technology enabling singularization, parallelization and miniaturization, which results in a strong cost reduction.[1] However, current microfluidic screening platforms are still expensive and bulky, mainly because they require sophisticated equipment like high-end microscopes and complex optical setups.[2] In order to achieve sim-

ple, fast and multi-parametric sample detection, integration of optical fiber systems into microfluidic devices is envisioned. Thereby microorganisms and their valuable compounds can be analyzed via fluorescence, absorbance and possibly other powerful spectrometric methods like Raman. The developed technology could be easily adopted for other microbiological applications like microbial interaction study, antibiotic susceptibility assays, biochemical assays, etc. [1] Guo, M. T., Rotem, A., Heyman, J. A., Weitz, D. A. (2012). Droplet microfluidics for high-throughput biological assays. Lab on a Chip, 12(12), 2146. [2] Gielen, F., Hours, R., Emond, S., Fischlechner, M., Schell, U., Hollfelder, F. (2016). Ultrahigh-throughput–directed enzyme evolution by absorbance-activated droplet sorting (AADS). Proceedings of the National Academy of Sciences, 113(47).

Systems biology Detection of Mutations in the gyrA Gene of Salmonella enterica Serovar Typhi Mahsa Roshandel, Shadi Ghalami Department of medical Biotechnology, university of Siena, Siena, Italy Salmonella is a member of the family Enterobacteriaceae are gram negative bacteria have flagella and are able to move the majority of serotypes. The material in aerobic or anaerobic growth conditions, it is best 37 ◦ C temperature and pH of 6 to 8. On the cell surface lipopolysaccharide antigen (antigen o) and Tazhhay proteins (antigens H) is obtained. Food poisoning caused by Salmonella often accompanied by diarrhea, vomiting, fever, and sometimes there is blood in the stool. Jyraz has several subunits of DNA that can be gyrA, gyrB, gyrC noted. Identification of mutations in the subunit DNA Jyraz using the RFLP-PCR and MAS-PCR is possible types of point mutations, which can be determined by RFLP-PCR identified a mutation in gyrA that causes resistance to nalidixic acid and tetracycline can cause mutations in ASP87, SER83 will happen. And mutation on codon 83 is greater than 87. [1] Alberts B, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2002). Isolating, Cloning, and Sequencing DNA. Garland Science. ISBN: 10: 0-8153-4072-9. [2] Angulo FJ (2006). Salmonella enterica Serotype Enteritidis and Eggs: A National Epidemic in the United States. Food safety. 43: 512-7. [3] Boyd D, Peters GA, Cloeckaert A, Boumedine KS, Chaslus-Dancla E, Imberechts H, Mulvey MR (2001). Complete nucleotide sequence of a 43-kilobase genomic island associated with the multidrug resistance region of Salmonella enterica serovar Typhimurium DT104 and its identification in phage type DT120 and serovar Agona. J. Bacteriol. 183:5725-5732.

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Evaluation of Antibacterial activities and Molecular docking studies of Di-peptide Shylesh Murthy [1], Mousami Das [2], Vivek Chandramohan [2], Makari Hanumanthappa [1], Hithesh Kumar [3] [1] IDSG Government College, Chikmagalur, India [2] Siddaganga Institute of Technology,Tumkur, India [3] GenEclat, Bangalore, India Antimicrobial peptides are potent agents with diverse structural and antimicrobial peptides, which represent one of the most promising future drugs for combating infections and microbial drug resistance. Understanding the versatile biological properties of antimicrobial peptides can be of extreme importance, for clinical development of peptide based therapeutics, this review is an attempt to illustrate the diversity of peptides reported for a potential. The search for potential antimicrobial peptide sequences was covering all the major peptide databases like Antimicrobial Peptide Database, Collection of Antimicrobial Peptide Databases (CAMP), Peptide Atlas, etc. Our current study aimed at the discovery of potent Fmoc-TrypAla-OMe was prepared and coupled with various amino acids and di-peptide these synthesized derivatives were characterized and screened for their antibacterial activity for various bacteria. Further, molecular docking studies revealed the potential of drug molecules. The result demonstrates the bioactive compound analysis and molecular docking studies, protein-ligand docking shows better binding interactions, they exhibit reasonable inhibitory activity and further employed to design derivatives with customized activities. These potential drug promises to overcome the bacterial drug resistance. Our research study helped in understanding the usefulness of synthetic peptides in treating diseases and further research can be continued, these have become a major challenge in in sillico and in vitro studies. [1] Giuliani A, Pirri G, Nicoletto SF (2007). Antimicrobial peptides: an overview of a promising class of therapeutics. Central European journel of pharmacy. 2(1) 1-33. [2] Chakraborty TK et al. (2004). Sugar amino acids and related molecules: some recent developments. Journal of chemical sciences 116(4): 187-207. [3] Chen HM et al. (1996). Antioxidant activity of designed peptides based on the antioxidative peptide isolated from digests of a soybean protein. Journal of agricultural and food chemistry. 44(9): 26192623. [4] Chen R et al. (2003). „ZDOCK: An initial-stage protein-docking algorithm." Proteins: Structure, Function, and Bioinformatics 52(1): 80-87. [5] Ciccotti G. et al. (2014). Molecular Dynamics Simulation, MDPI AG Basel, Switzerland. [6] David A et al. (2013). Antimicrobial Peptides: Their History,

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Evolution, and Functional Promiscuity, Wiley-VCH, Germany. [7] Dammalli M et al. (2014). In silico analysis and identification of novel inhibitor for new H1N1 swine influenza virus. Asian Pacific Journal of Tropical Disease. 4: S635-S640. [8] Ghahremanpour MM et al. (2015). The effect of structural parameters and positive charge distance on the interaction free energy of antimicrobial peptides with membrane surface. Journal of Biomolecular Structure and Dynamics. 33(3): 502-512. [9] Giordano A (2013). Bioactive Peptides in Cancer: Therapeutic Use and Delivery Strategies. [10] Hancock RE et al. (2000). Antibiotic resistance in Pseudomonas aeruginosa: mechanisms and impact on treatment. Drug resistance updates. 3(4): 247-255.

Dimensionality of motion and binding valency govern receptor-ligand kinetics as revealed by agent-based modelling Teresa Lehnert [1], Marc Thilo Figge [1,2] [1] Research Group Applied Systems Biology at the Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI) Jena, Center for Sepsis Control and Care (CSCC) Jena, Jena, Germany [2] Faculty of Biology and Pharmacy at the Friedrich Schiller University Jena, Jena, Germany The interaction between receptors and ligands is a fundamental part of signalling mechanisms in the human body, such as the immune response against microbial pathogens. Mathematical models become increasingly essential to get insights into such complex mechanisms. The affinity of pathogen derived antigens to immunoglobulins strongly influences parts of the specific immune response against pathogens. Immunoglobulins are characterised by a Y-shaped morhpology, which provides two sites for binding of antigens. Furthermore, immunoglobulins occur in the human body as membrane-anchored B cell receptors (BCR) and as soluble antibodies. We investigated the impact of these receptor characteristics to receptor-ligand (RL) binding dynamics using a molecular agentbased modelling (ABM) framework. The ABM comprises spatial objects - the agents - that represent ligands and receptors, which move and interact according to predefined rules within a threedimensional environment. Based on this framework, we implemented certain ABM variants that differ in dimensionality of receptor motion to investigate the influence by membrane-anchored BCR and soluble antibodies. Furthermore, we implemented ABM variants with different receptor morphologies, i.e. Y-shaped receptors and receptors with a simple spherical morphology. The binding dynamics of these microscopic ABM variants were quantified by the RL kinetics of a macroscopic ordinary differential equation model which reveals a mapping between the macroscopic and microscopic viewpoint on RL binding. The resulting

POSTERS - SYSTEMS BIOLOGY quantitative characteristics of the different ABM variants indicate that the dimensionality of motion governs the binding kinetics and that this predominant impact is, however, quantitatively compensated by the bivalency of these receptors. In the future, this molecular ABM can be used to investigate co-receptor binding as well as cluster formation of receptors as being essential steps in B cell activation. Dynamic optimization of pathway regulation and cytoxicity prediction of metabolites in pathogenic fungi exploit the hidden potential of toxic metabolites as drug targets Jan Ewald [1], Martin Kötzing [1], Martin Bartl [1], Thomas Dandekar [2], Humberto González-Díaz [3] and Christoph Kaleta [4] [1] Theoretical Systems Biology, Friedrich-SchillerUniversität Jena, Jena, Germany [2] Department of Bioinformatics, Biocenter, JuliusMaximilians-Universität Würzburg, Würzburg, Germany [3] Ikerbasque, Basque Foundation for Science and Department of Organic Chemistry II, University of the Basque Country, Leioa, Spain [4] Medical Systems Biology, Christian-AlbrechtsUniversität Kiel, Kiel, Germany The understanding of metabolism and its regulation is crucial for a holistic comprehension of biological processes. However, the time dependency is often lowly resolved or completely neglected, but is important to recover the principles behind regulation. To fill those gaps, dynamic optimization has been used to identify principles shaping regulatory networks controlling metabolism by assuming optimality principles underlying pathway control [1, 2]. The modeling of a linear metabolic pathway with different kinetic properties and toxicity of metabolites lead us to principles validated by large scale metabolic data sets of various organisms. In our present study [3], we focus on the impact of toxic metabolites on the regulatory strategies controlling metabolic pathways. We found that toxic metabolites are controlled by a tight regulation of upstream enzymes preventing their accumulation, which changes the position of the mainly regulated enzyme. These findings can explain a sparse regulation by key enzymes at various positions of a pathway and not mainly at the first and last position, as observed previously [4, 2]. Our latest results suggest that these optimality principles are shared by bacteria as well as eukaryotes like the pathogenic fungi Aspergillus fumigatus or Candida albicans. Since there only few known compounds that impede growth of fungi while not affecting the human host, we created a framework to predict the cytoxicity of metabolites in fungal cells based on

their structure to identify targets for antimicrobial interventions. Beyond this, we integrated the results with networks of the KEGG database to build a easy to use visualization of toxic metabolites in metabolic networks to identify drug targets. Together with our findings of optimality principles in pathway regulation, this provides a new avenue of drugs that induce self-poisoning based on the perturbation of highly regulated enzymes that prevent the accumulation of toxic metabolites. [1] Bartl M et al. (2013). Dynamic optimization identifies optimal programmes for pathway regulation in prokaryotes. Nature communications. 4. [2] De Hijas-Liste GM et al. (2015). Optimal programs of pathway control: dissecting the influence of pathway topology and feedback inhibition on pathway regulation. BMC bioinformatics. 16(1):163. [3] Ewald J et al. (2017) Optimality principles reveal a complex interplay of intermediate toxicity and kinetic efficiency in the regulation of prokaryotic metabolism. PLOS Computational Biology. 13(2):e1005371. [4] Wessely F et al. (2011). Optimal regulatory strategies for metabolic pathways in escherichia coli depending on protein costs. Molecular systems biology. 7(1):515.

Migration and interaction tracking for quantitative analysis of phagocyte-pathogen confrontation assays Susanne Brandes [1,2], Stefanie Dietrich [1,2], Kerstin Hünniger [3], Oliver Kurzai [3,4], Marc Thilo Figge [1,2] [1] Applied Systems Biology, Leibniz Institute for Natural product research and Infection Biology, Hans Knöll Institute, Jena, Germany [2] Friedrich Schiller University, Jena, Germany [3] Septomics Research Center, Friedrich Schiller University and Leibniz Institue for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany [4] Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany Invasive fungal infections are emerging as a significant health risk for humans. The innate immune system is the first line of defence against invading micro-organisms and involves the recruitment of phagocytes, which engulf and kill pathogens, to the site of infection. To gain a quantitative understanding of the interplay between phagocytes and fungal pathogens, live-cell imaging is a modern approach to monitor the dynamic process of phagocytosis in time and space. However, this requires the processing of large amounts of video data that is tedious to be performed manually. Here, we present a novel framework, called AMIT (algorithm for migration and interaction tracking [1]), that enables automated high-throughput analysis of multi-channel time-lapse microscopy videos of phagocyte-pathogen confrontation as-

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says. The framework is based on our previously developed segmentation and tracking framework for non-rigid cells in brightfield microscopy [2]. We here present an advancement of this framework to segment and track different cell types in different video channels as well as to track the interactions between different cell types. For the confrontation assays of polymorphonuclear neutrophils (PMNs) and Candida glabrata considered in this work, the main focus lies on the correct detection of phagocytic events. To achieve this, we introduced different PMN states and a statetransition model that represents the basic principles of phagocyte-pathogen interactions. The framework is validated by a direct comparison of the automatically detected phagocytic activity of PMNs to a manual analysis and by a qualitative comparison with previously published analyses [3, 4]. We demonstrate the potential of our algorithm by comprehensive quantitative and multivariate analyses of confrontation assays involving human PMNs and the fungus C. glabrata. [1] Brandes S, Dietrich S, Hünniger K, Kurzai O, Figge MT (2016). Migration and Interaction Tracking for Quantitative Analysis of Phagocyte-Pathogen Confrontation Assays. Medical Image Analysis. 36 (Nov.). 172-183. [2] Brandes S, Mokhtari Z, Essig F, Hünniger K, Kurzai O, Figge MT (2015). Automated segmentation and tracking of non-rigid objects in time-lapse microscopy videos of polymorphonuclear neutrophils. Medical Image Analysis. 20 (1). 34-51. [3] Duggan S, Essig F, Hünniger K, Mokhtari Z, Bauer L, Lehnert T, Brandes S, Häder A, Jacobsen ID, Martin R, Figge MT, Kurzai O (2015). Neutrophil activation by Candida glabrata but not candida albicans promotes fungal uptake by monocytes. Cellular Microbiology. 17 (May). 1259-1276. [4] Essig F, Hünniger K, Dietrich S, Figge MT, Kurzai O (2015). Human Neutrophils dump Candida glabrata after intracellular killing. Fungal Genetics and Biology. 84 (Nov.). 37-40.

Microbial camouflage by Candida albicans using human factor H - a numerical model Stefan Lang [1], Sebastian Germerodt [1], Christina Glock [1], Christine Skerka [2], Peter Zipfel [2], Stefan Schuster [1] [1] Dept. of Bioinformatics, Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, D-07743 Jena, Germany [2] Dept. of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany Molecular mimicry is the formation of ’eclipsed’ molecules by parasites to avoid recognition and suppression by the immune system of the host. For example, several pathogenic Ascomycota and Zygomycota show such a behaviour, deceiving, in particular, the innate immune system. For example, Candida albicans binds human regulators like complement factor H and, thus, hides from the

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complement system. Such a camouflage can reach a point where the immune system can no longer clearly distinguish between self and non-self. This implies that a trade-off between attacking possible pathogens and own cells has to be made, which can in turn lead to autoimmunity. When studying mimicry by animals, is often modeled using methods of signal detection and game theory. Based on these methods, we here present a model of molecular mimicry by C. albicans involving human factor H. The main questions are to which extent microbes can deceive the host immune system and how the host can respond to enable a distinction between host cells and camouflaged microbes. Modeling the metabolic reprogramming of macrophage activation Franziska Hoerhold [1,2], Marcus Oswald [1,2], Rainer König [1,2] [1] Associated Group of Network Modeling, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute, Jena, Germany [2] Center for Sepsis Control and Care, University Hospital, Jena, Germany In response to their microenvironment, resting macrophages can polarize mainly into two distinct phenotypes: M1 (classical activation e.g. by microbial products or IFN- γ ) or M2 macrophages (alternative activation e.g. by IL-4). M1 macrophages can produce pro-inflammatory mediators such as TNF-α, IL-1 and nitric oxide [3] and can mediate an inflammatory response leading to a cytokine storm triggering sepsis. In contrast, M2 macrophage show a rather immunosuppressive behavior during sepsis [5]. Hence, a central aim in critical care is to reduce M1 and induce M2 activation. A metabolic switch of M1 compared to M2 macrophages had been described by upregulation of aconitate decarboxylase in M1 macrophages, which synthesizes itaconate from cis-aconitate [1], M1 macrophages modulate the citrate cycle such that nitric oxide is produced in the urea cycle [1], and other studies showed that a transition of M1 to M2 macrophages can be induced by IL-4 [4, 6]. In order to understand the switch in regulation of metabolism, we investigate the regulation using our newly develop tool [7] and model metabolic fluxes to identify regulators which are responsible for the metabolic switch. Methodologically, we show an approach based on mixed-integerlinear programming, which integrates C13 labeling data to predict metabolic fluxes. It contains a new method to remove futile cycles which will be compared to a method from the constraint-based reconstruction and analysis (COBRA) framework [2]. Our study revealed promising results that help elucidating the metabolic and transcriptional re-

POSTERS - SYSTEMS BIOLOGY programming of M1 and M2 macrophages after activation. [1] Jha AK, Huang SCC, Sergushichev A, Lampropoulou V, Ivanova Y et al. (2015). Network Integration of Parallel Metabolic and Transcriptional Data Reveals Metabolic Modules that Regulate Macrophage Polarization. Immunity. 42. 419-430. [2] Schellenberger J, Lewis NE, Palsson BØ (2011). Elimination of Thermodynamically Infeasible Loops in Steady-State Metabolic Models. Biophysical Journal. 100. 544-553. [3] Stearns-Kurosawa DJ, Osuchowski MF, Valentine C, Kurosawa S, Remick DG (2011). Pathology in Sepsis. Annual review of pathology: mechanisms of disease. 6. 19-48. [4] Spiller KL, Nassiri S, Witherel CE, Anfang RR, Ng J, et al. (2015). Sequential delivery of immunomodulatory cytokines to facilitate the M1-to-M2 transition of the macrophages and enhance vascularization of bone scaffolds. Biomaterials. 37. 194-207. [5] Wynn TA, Chawla A, Pollard JW (2013). Macrophage biology in development, homeostasis and disease. Nature. 496. 445-455. doi:10.1038/nature12034. [6] Zheng XF, Hong YX, Feng GJ, Zhang GF, Rogers H et al. (2013). Lipopolysaccharide-Induced M2 to M1 Macrophage Transformation for IL-12p70 Production Is Blocked by Candida albicans Mediated Up-regulation of EBI3 Expression. PLoS ONE. 8. e63967. [7] Poos AM, Maicher A, Dieckmann AK, Oswald M, Eils R, Kupiec M, Luke B, König R (2016). Mixed Integer Linear Programming based machine learning approach identifies regulators of telomerase in yeast, Nucleic Acids Research. 44. e93.

Raman spectroscopic investigation of human neutrophil interactions with sepsis-associated pathogens Angelina Pittner [1,2], Natalie Töpfer [1,3], Marcel Dahms [1,2,3,4], Anuradha Ramoji [1,3], Oliver Kurzai [1,2,5], Jürgen Popp [1,3,4,6], Ute Neugebauer [1,3,4,6] [1] Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany [2] Friedrich-Schiller-University Jena, Jena, Germany [3] Leibniz Institute of Photonic Technology, Jena, Germany [4] InfectoGnostics Research Campus Jena, Reg. Assoc., Jena, Germany [5] Septomics Research Center - Leibniz Institute of Natural Product Research and Infection Biology - Hans Knoell Institute, Jena, Germany [6] Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Jena, Germany For sepsis patients a fast and reliable identification of infection causing pathogens is crucial to apply appropriate antibiotic therapy which increases survival rates. Raman spectroscopy as a rapid, non-invasive and label-free tool has been refined to identify multiple microbial species based on their spectral fingerprints [1, 2, 3]. Since pathogens are difficult to detect in blood this study focuses on human polymorphonuclear neutrophils (PMNs)

as the first line of defence against pathogens by phagocytosis and distinct killing mechanisms. Here, Raman spectroscopy was used for characterisation of infected PMNs to identify classes of microorganisms. PMNs were isolated from blood of healthy volunteers and incubated with heat-killed Gram + (S. aureus), Gram- (E. coli) and fungal (C. albicans) pathogens as well as live fungi for 1h. After fixation Raman spectra of PMNs were acquired and used for classification models and imaging by spectral unmixing. PMN activation was assessed by measuring cell viability, ROS production and Interleukin-8 (IL-8) release. Stimulated and unstimulated PMNs were distinguished by their Raman spectral profile with ~90% accuracy. Additionally, spectral patterns of PMNs challenged with bacteria or fungi differed as well as patterns of PMNs activated by S. aureus or E. coli and live or dead fungi, respectively. After incubation >87% of PMNs were viable. ROS production was highest in PMNs activated by bacteria whereas IL-8 release was significantly elevated for PMNs infected with live fungi. Image analysis revealed a higher DNA content in fungal confronted PMNs. Spectral variations seem to originate from both, pathogen’s spectra and host cell’s distinct activation patterns as a reaction to different microbial species. These findings encourage further whole-blood infection experiments combined with Raman spectroscopy and provide new approaches of culture- and labelfree diagnostic tools for sepsis. Funding from DFG via JSMC is highly acknowledged. [1] Neugebauer U, Rösch P, Popp J (2015). Raman spectroscopy towards clinical application: drug monitoring and pathogen identification. International Journal of Antimicrobial Agents. 46 Supplement 1. S35-S39. [2] Maquelin K, Kirschner C, Choo-Smith LP, Ngo-Thi NA, van Vreeswijk T, Stämmler M, Endtz HP, Bruining HA, Naumann D, Puppels GJ (2003). Prospective study of the performance of vibrational spectroscopies for rapid identification of bacterial and fungal pathogens recovered from blood cultures. Journal of Clinical Microbiology. 41 (1). 324-329. [3] Maquelin K, Choo-Smith LP, Endtz HP, Bruining HA, Puppels GJ (2002). Rapid identification of Candida species by confocal Raman microspectroscopy.Journal of Clinical Microbiology. 40 (2). 594600.

Effect of organic products on the improvement of soil microbiological functioning under saline conditions of arid regions: Impact on carbon and nitrogen mineralization Mabrouka Oustani [1], Mohammed Tahar Halilat [1], Haroune Chenchouni [2] [1] University of Kasdi Merbah Ouargla, Ouargla, Algeria [2] University of Tebessa, Tebessa, Algeria The study was conducted on representative and

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contrasting soils of arid region. It focuses on the compared influence of various organic products: Poultry manure (PM), Bovine Manure (BM), Goat Manure (GM), Dromadory Manure (DM) and Date Palm Residues (DPR) on improvement of microbial functioning of non-saline (NS) and saline (SS) soils, in particular, mineralization process of nitrogen and carbon. The microbiological activity was estimated by respirometric test (CO2 emissions) and the extraction of two forms of mineral nitrogen (NNH4 + and N-NO3 - ). After 56 days of incubation under controlled conditions (28◦ C and 80% of CR ), the various organic products indicated a significant variation in mineralization activity following the type of soil and organic product added. However, the highest cumulative quantities of CO2 , N-NH4 + and N-NO3 - obtained at the end of incubation were recorded in non-saline soil (NS) treated with poultry manure 1173.26, 7.26 et 14.91 mg 100-1 g of dry soil, respectively. The reduction rates of release of CO2 , N-NH4 + and N-NO3 - under saline conditions were 16, 3.26 and 18%, respectively. The influence of organic products on the microbial density shows a stimulating effect on all microbial groups studied. All the results obtained revealed the interest of different organic products to improve the microbiological functioning in saline soils of arid regions. In silico experiments of fungal and bacterial infections in virtual neutropenic patients suggest optimal treatment strategies Sandra Timme [1,2], Maria Prauße [1,2], Teresa Lehnert [1], Kerstin Hünniger [3], Oliver Kurzai [2,3], Marc Thilo Figge [1,2] [1] Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology – HansKnöll-Institute (HKI), Jena, Germany [2] Friedrich Schiller University Jena, Jena, Germany [3] Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute (HKI), Jena, Germany The human immune system protects the body against various environmental cues, like viral, bacterial and fungal invaders. However, inborn or acquired diseases as well as medical treatments may impair the proper functioning immune system. Such an impairment is neutropenia, i.e. a reduction in the absolute neutrophil count, that is associated with much higher risk for bacterial and fungal infections. Therefore, it is of high importance to understand the interaction of immune cells and pathogens in health and disease. Here we apply a systems biology approach, that incorporates wetlab and dry-lab techniques complementing each other. We performed infection assays with human whole-blood, where blood from healthy donors

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was infected with different pathogens and measured their phagocytosis and killing at several time points [1]. Based on these data, we developed in a previous study a bottom-up virtual infection model using state-based and agent-based modelling in order to quantify immune reaction rates as well as spatial aspects including immune cell migration [2]. In our current study we apply this bottom-up approach to investigate the interaction of innate immune cells, like monocytes and neutrophils, and the two fungal pathogens Candida albicans and Candida glabrata as well as the gram-positive bacterium Staphylococcus aureus. However, we investigate this interaction not only under healthy conditions but also simulate the condition of neutropenia and possible treatment strategies. We show that the infection outcome under neutropenic conditions can be improved by increasing the phagocytosis rate as well as the migration speed of neutrophils. For future studies we also want to simulate alternative treatment strategies like the supplementation of neutrophils from donors. [1] Hünniger K, Lehnert T, Bieber K, Martin R, Figge MT, Kurzai O (2014). A virtual infection model quantifies innate effector mechanisms and Candida albicans immune escape in human blood. PLoS Comput Biol. 10(2):e1003479 [2] Lehnert T, Timme S, Pollmächer J, Hünniger K, Kurzai O, Figge MT (2015) Bottom-up modeling approach for the quantitative estimation of parameters in pathogen-host interactions. Frontiers in Microbiology. 6(608).

Iron redistribution after Candida albicans infection in the murine kidney Theresia Conrad [1], Agatha. Kilar [2], Reinhard Guthke [1], Jörg Linde [1] [1] Systems Biology/Bioinformatics, Leibniz-Institute for Natural Product Research and Infection Biology – Hans-Knoell-Institute, Jena, Germany [2] Silesian University of Technology, Gliwice, Poland Candida albicans is a major fungal pathogen of mammals and frequently causes life-threatening nosocomial fungal bloodstream and disseminated infections. Although C. albicans initially infects almost all organs as a result of an intravenous infection, previous studies focus on the murine kidney as the prime target organ for disseminated candidiasis. [1] During the infection, the host initiates different immune defense strategies to overcome invaded pathogens. One of the strategies is the withholding of nutrients, called ’nutrient immunity’. [2] As iron is an essential micronutrient for most organisms, in this study we focus on the redistribution of iron in consequence of an invasive candidiasis in the murine kidney. We want to answer the question whether there is a link between the iron redistribution and the directed growth of C. albicans in direction to the renal pelvis. With the

POSTERS - SYSTEMS BIOLOGY aid of NetLogo, a multilevel agent-based model was developed to demonstrate the dependence of a progressive C. albicans infection on the kidneyspecific iron distribution. The results suggest that the directed growth of C. albicans is directly associated with the renal iron redistribution. Contrary to expectations, the activation of the iron redistribution leads to an increased growth of fungal cells. Thus, the model predicts that the iron redistribution – initially initiated to overcome the invaded pathogens - promotes the spread of the C. albicans infection. This leads to the hypothesis that nutrient immunity is only a semi-effective strategy in supporting the battle against fungal infections. [1] Lionakis et al. (2011). Organ-Specific Innate Immune Responses in a Mouse Model of Invasive Candidiasis. J Innate Immun. 3:180199. [2] Potrykus et al. (2013). Fungal Iron Availability during Deep Seated Candidiasis Is Defined by a Complex Interplay Involving Systemic and Local Events, PloS Pathog. 9(10): e1003676.

Enhanced Detection of Unstained Cells in an Existing Segmentation and Tracking Framework Naim Al-Zaben [1,2,3], Anna Medyukhina [1], Alessandra Marolda [2,4], Kerstin Hünniger [4], Oliver Kurzai [4,5], Marc Thilo Figge [1,2] [1] Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Germany [2] Friedrich Schiller University Jena, Germany [3] Jena School for Microbial Communication (JSMC), Germany [4] Fungal Septomics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Germany [5] Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany

mostly happens for flattening cells causing transient failures in the track detection associated with a fragmentation of cell tracks. The enhancements we have introduced affect both segmentation and tracking of the cells. The existing framework uses a Gaussian Mixture Model (GMM) to identify cells, where the input is a combination of the temporal and spatial intensity variances. The output is split into three classes: (i) mobile, (ii) static elements and (iii) background. This approach, however, failed to detect the cells that flatten by detecting them as static elements that are neglected in the subsequent tracking. We enhanced the detection of cells by revising the GMM classification in a way that flat cells are captured and integrated into the subsequent tracking procedure. To avoid overdetection, we consider only tracks of flat cells that can be combined with previously existing tracks. This enhancement results into improved continuous tracking of cells with considerably less track fragmentation. [1] Brandes S, Mokhtari Z, Essig F, Hünniger K, Kurzai O, Figge MT (2015) Automated segmentation and tracking of non-rigid objects in time-lapse microscopy videos of polymorphonuclear neutrophils. Medical Image Analysis 20 (1), 34-51.

Today, time-lapse microscopy experiments are routinely performed in biological research, however, usually the acquired images are used for illustrative purposes only. This disregard of quantitative information on dynamical, functional and morphological aspects of the biological system under consideration is due largely to the lack of systematic strategies for the appropriate processing and for the statistical analysis of image data. We present enhancements to an existing automated segmentation and tracking framework for videos from live cell imaging [1]. The framework handles variable cell shapes and does not rely on cell staining. The segmentation approach is based on a combination of spatial and temporal image variations in pixel intensities to detect moving cells in the microscopy videos. Although the existing framework performs well in detecting and tracking cells, it fails to do so in cases where some of the cells become undetectable due to a low spatial variance. This

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Imprint Conference host Jena School for Microbial Communication (JSMC) Friedrich Schiller University Jena Neugasse 25, 07743 Jena, Germany Contact information of the JSMC office Telephone: +49 (0)3641 930421 Email: [email protected], [email protected] Editorial board Rober Barnett Iuliia Viediernikova Michael Gaspar Booklet design Michael Gaspar Logo Ivan Gaspar Printing Pigmentpol Thüringen GmbH Picutre credits Page 2: Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute Page 5: Franz Berke Page 22: Haus auf der Mauer, Landgrafen Restaurant & Event GmbH, Jürgen Scheere Page 23: W. Don Eck, ART-KON-TOR, Anna Schroll, Cosmic Dawn, Elisabeth Hase

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