Study on Microbial Oil Production with Chlorella pyrenoidosa

Chlorella pyrenoidosa No.2 was screened from five species of microalga Chlorella sp. for its higher lipid yield. Effects of medium components and culture conditions on cell growth as well as lipid ac-cumulation of C. pyrenoidosa No.2 were investigated and the results showed that the optimum medium rec-ipe was 20.0 g/L glucose,0.08 g/L glycine,1.0 g/L K2HPO4·3H2O,0.4 g/L MgSO4·7H2O and 0.004 g/L FeSO4·7H2O. The optimum culture temperature,initial pH,shaking rate and light intensity were 28℃,6.0,130 r/min and 650 Lux,respectively. Biomass and lipid content increased from 3.73 g/L and 40.15% to 6.56 g/L and 59.90% when Chlorella pyrenoidosa No.2 was cultivated under the above optimal conditions for 7 days,with lipid yield raised by 162%. Chlorella pyrenoidosa No.2 could produce lipid with xylose as carbon source,and so is potential for lipid production from renewable materials such as lignocellulose. GC analysis demonstrated that the fatty acid composition of the lipid was similar to that of vegetable oil and its unsaturated fatty acid content reached around 71%,thus it is a promising material for biodiesel production.