Abstract:The effects of 2% CO2 supplement or air (contain 0.04% CO2) on cell specific growth rate, biomass dry weight, content and yield of total fatty acids, neutral lipids content of Coccomyxa subellipsoidea C-169 grown autotrophically in Basal and BBM media were investigated in this study. Compared with the results from aeration with air, 2% CO2 supplement significantly increased the cell specific growth rate of 2.6 times in Basal medium and 2.3 times in BBM medium, respectively. After cultured for 13 days, the maximal biomass concentration was obtained at 4.67 g/L by 2% CO2 supplement in Basal medium, which was much higher than other groups (p < 0.05). The highest content of total fatty acids reached 37.53% (DW) by supplying 2% CO2 in BBM medium, which was 5 times higher than that by inletting air. And the yield of total fatty acids was up to 77.49 mg/(L?d) while neutral lipids referred as fluorescence intensity was significantly higher than other groups (p＜0.05). These results indicated that 2% CO2 supplement in Basal medium could promote cells to produce more biomass. In BBM medium, it could increase the yield of fatty acids and neutral lipids in the microalga, which was excellent raw material for biodiesel production.
