Abstract: The effects of carbon source, nitrogen source, carbon-nitrogen ration, pH value and temperature on the biomass and lipid concentration were studied in the fermentation condition of Chlorella pyrenoidosa FACHB-29 by the single factor and orthogonal experiments. First, the single factor was used to evaluate the influence of the related factors. Then, the three factors affecting the biomass and lipid concentration notably were screened out as glucose concentration, ammonium nitrate concentration and pH value. Finally, the optimum conditions for the cell growth were determined through the orthogonal test, that is, 2% glucose concentration, 0.016% ammonium nitrate concentration, and pH value 7.5. Under the optimum conditions, the Chlorella pyrenoidosa cell concentration reached 5.6 g/L in the fermentation, and the lipid yield reached 1.46 g/L.

Key words: Chlorella pyrenoidosa, fermentation condition, lipid, biodiesel