바이오 디젤 생산을 위한 해양 미세조류(Dunaliella tertiolecta,Tetraselmis chui, Nannochloropsis oculata)최적배양에 관한 연구

Abstract

Recently, there is a growing interest in microalgae and the use of microalgae focused on the production of various high valued metabolites used for food, pharmaceuticals, and cosmetics. The rate of depletion of fossil fuels and the effect of greenhouse gas emissions on global climate change evoke much interest in biodiesel. Microalgae have been issued much more as the factory for biodiesel production due to their several potential advantages ; high yield of neutral lipid/oil as 20-50%, high growth rate, viability in extremely arid condition, doing major roles in wastewater treatment, removers of carbon dioxide and producers of valued chemicals and much higher biomass production in a suitable vessel compared to those of terrestrial plants in the same area. In this study, three species of marine microalga Tetraselmis chui, Dunaliella tertiolecta and Nannochloropsis oculata were cultured to investigate three important growth factors such as CO2 concentration, light intensity and light-cycle. The cell growth rate, biomass productivity, oil content and fatty acid composition of T. chui, D. tertiolecta and N. oculata, candidates for biodiesel production were measured using 1L photobioreactor. The productivity of cell mass and oilcontent increased with repeated fed-batch culture. The optimal conditions for cell growth and oil production at 23℃, light intensity 110μmol/m2/s, and light cycle 14:10(L:D), it was transferred to 1L photobioreactor its medium composition was F/2-Si × 3 medium. And filtered air containing 2% CO2 was injected into the conical bottom part of the photobioreactor at a constant flow rate of 1vvm. The repeated fed-batch system was adopted to increase the cell mass and oil content productivity for 2 weeks. The cell was harvested every other days. Biomass productivity and oil content of T. chui were 0.415 g/L/day and 0.170 g/L, respectively. Those of D. tertiolecta were 0.478 g/L/day and 0.173 g/L, respectively.