Cultivation of A. platensis based on the optimum concentrations of urea and triple super phosphate, ammonium sulfate and phosphoric acid, ammonium nitrate and triple super phosphate Nurshazreen Mashor, Mohd Shahmen Mohd Yazam, Mohamed Amar Naqqiuddin, Hishamuddin Omar & Ahmad Ismail Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang Selangor, Malaysia Corresponding author:
[email protected]
INTRODUCTION
PROBLEM STATEMENT
In order for outdoor cultivation of A. platensis to be successful, management measures should be taken to ensure good microalgae cultivation is suitable for the environment in Malaysia in line with the development of the aquaculture industry. Since A. platensis growth are majorly influenced by environmental conditions such as light, temperature, and nutrient, it is necessary to study those interactions in Malaysia (Naqqiuddin et al., 2014). Standard growth media: Kosaric medium (Tompkins et al.,1995)
Presently there is no cheap fertilizer available for commercial A. platensis cultivation in Malaysia. Therefore it is very important to develop cheap fertilizer from easily available chemicals to reduce production cost. There are several aspects that need to be improved in current fertilizer formula that will be used towards production of microalgae in a large scale in the future (Nor et al., 2015).
MATERIALS AND METHODS
Nitrogen and phosphorus were replaced by (g L-1): urea, 0.1608, ammonium nitrate, 0.2143 and ammonium sulphate, 0.3538 and triple superphosphate (TSP), 0.0663 or phosphoric acid, 0.0703
Preparation of HDPE bag photobioreactor
A. platensis was grown in four different culture treatments. 30L of freshwater was mixed with enrichment
solutions in high-density polyethylene (HDPE) bags (60cm x 90cm) special manufactured with the addition of ultra violet (UV) protection. Inoculum size of 10% was used to initiate A. platensis culture with optical density of 0.2471. Growth performance was monitored daily, while chlorophyll a pigment content was monitored at alternate day. Spirulina was harvested using nylon cloth at its stationery phase or at higher levels of growth. One layer of black plastic orchid netting and rope were used as the roofing material to provide protection against rain, and intense irradiance from sunlight. Aeration was supplied from an air pump via plastic tubing with suspended air stones placed in each culture bag to provide continuous mixing and agitation.
RESULT
FIGURE 1: Sheltered HDPE bags photobioreactor.
FIGURE 2: Optical density and dry weight of A. platensis as cultured in Kosaric media (control), T1 (urea + tsp, low concentration), T2 (ammonium sulphate + phosphoric acid, high concentration), T3 (ammonium nitrate + tsp, low concentration)
DISCUSSION Similar finding was also reported by Soletto et al., (2005) that the growth of A. platensis was high in urea compared to ammonium sulphate, while Madkour et al. (2012) reported ammonium nitrate’s grown Spirulina gained higher than urea. The advantage of urea as substituted nitrogen source is it can easily hydrolysed to ammonium in alkaline condition and can be used by A. platensis. In addition, the cultivation with urea as nitrogen source exhibited better cellular growth curve as the ammonia in the culture could enter directly into the cells without energy expenditure at particular pH condition. To overcome the nitrogen source limitation, pulse fertilization process was believed to give exponentially increased mass flow and indeed can avoid the inhibitory ammonia concentration in the cultivations fertilized with urea (Danesi et al., 2002). REFERENCES Danesi, E.D.G., Rangel,C.O., de Carvalho, J.C.M., & Sato,S. (2002). An investigation of effect of replacing nitrate by urea in the growth and production of chlorophyll by Spirulina platensis.Biomass and Bioenergy . 261-269. Madkour,F.F., Kamil, A.W., & Nasr, H.S. (2012). Production and nutritive value of Spirulina platensis in reduced cost media. Egyption Journal of Aquatic Research. 51-57. Naqqiuddin, M.A., Nor, N.M., Omar, H. & Ismail A. 2014a. Development of simple floating photobioreactor design for mass culture of Arthrospira platensis in outdoor conditions: Effects of simple mixing variation. Journal of Algae Biomass Utilization 5(3): 46-58. Nor, N.M., M,A. Naqqiuddin, N. Mashor, S. Zulkifly, H. Omar, & A. Ismail. 2015. The effect of different nitrogen sources on continuous growth of Arthrospira platensis in simple floating photobioreactor design in outdoor conditions. Journal of Algal Biomass Utilization 6(4): 1-11. Soletto, D., Binaghi, L., Lodi, A., Carvalho, J.C.M., & Converti, A. (2005). Batch and fed-bach cultivations of Spirulina platensis using ammonium sulphate and urea as nitrogen sources. Aquaculture. 217-224. Tompkins J., Deville M.M., Day J.G. & Turner M.F. 1995. Catalogue of Strains. Titus Wilson and Son Ltd. Kendall. U.K., 166. Ugwu, C. U., Aoyagi, H., & Uchiyama, H. (2008). Photobioreactors for mass cultivation of algae. Bioresource Technology. 4021-4028
ACKNOWLEDGEMENT The authors thank Department of Biology, Faculty of Science, UPM, technical staffs from Plant Physiology Lab, University Putra Malaysia and those who contribute to fulfill to this paper.
