Development of stable recombinant cyanobacteria for economically competent solar fuel-factories: Ethylene production Veronica Carbonell, Eerika Vuorio, Eva-Mari Aro and Pauli Kallio Molecular Plant Biology, Department of Biochemistry, University of Turku, FINLAND. Contact:
[email protected]
1. AIMS AND STRATEGY:
O2
Bio-Ethylene:
H 2O
• Important Building block for chemical industry • Volatile and easy separation from biomass
Pseudomonas syringae
LIGHT REACTIONS
CO2 PEP
Calvin Cycle
pyruvate
Cyanobacteria: • • • •
ATP+NADPH
Acetyl-CoA citrate isocitrate
oxaloacetate TCA cycle
Arginine
High solar energy conversion CO 2 neutral Easy to engineer Found in a wide range of habitats.
CO2,Guanidine, P5C
Bioplastics
2-oxoglutarate
malate
succinic semialdehyde
fumarate succinate
Metabolic engineering
2. PROBLEM: GENETIC INSTABILITY S7942
PpsbA1
efe
Chromosome
3. SOLUTION: IMPROVE THE HOST ROBUSTNESS
TpsbA1
NSI
Ptrc
NSI
efe
STABLE
UNSTABLE 150
nl C2H4 mL-1h-1/OD750
nl C2H4 mL-1h-1/OD750
150
100
4. WHAT CAUSED GENETIC INSTABILITY? psbA1
Photosystem II D1:1 (PSII)
psbA2
D1:2
psbA3
D1:2
D1:1
100
50
0 1
2
3
4
Batch cultivation (Adapted from Takahama et al 2003)
efe 50
0 1
2
3
EFE
psbA2
D1:2
psbA3
D1:2
4
PSII
STRESS!!
Batch cultivation (Manuscript in preparation)
5. FUTURE PERSPECTIVES
6. ACKNOWLEDGMENTS
• Ensure gene replacement strategy through well characterized Neutral Sites. • Adapt ethylene expression systems to the strain-specific differences. • Achieve higher ethylene levels by enhancement of metabolic flux towards TCA cycle. • Optimize collection methods for ethylene, scale-up & commercialization.
• European Union Seventh Framework Programme (FP7-ENERGY-2010-1) [grant no. 256808] • Academy of Finland Centre of Excellence "Molecular Biology of Primary Producers" [grant no. 271832] • Finnish Cultural Foundation [grant no. 85141444] • Tekes [grant no. 40128/14]
