EFFECTS OF ENVIRONMENTAL FACTORS ON GROWTH AND LIPID ACCUMULATION OF CHLORELLA PYRENOIDOSA IN PHOTOBIOREACTOR

The effects of air aeration rate, nitrogen, Fe3+, IAA concentration, and CO2 supply volume on growth and lipid accumulation of microalgae Chlorella pyrenoidosa in airlift photobioreactor were studied. Results show that when the air aeration rate was 2.0L/min, the growth rate of C. pyrenoidosa was 6.17mg/(L·d) and the lipid production was 1.77mg/(L·d). During the experimental time, the nitrogen concentration did not affect the algal lipid production signifi- cantly. The optimal conditions of other factors were: Fe3+concentration at 0.1mmol/L for the best growth rate [7.29mg/(L·d)], and 1.0mmol/L for best lipid production [2.54mg/(L·d)]; IAA concentration at 1.0mg/L for both the growth rate and lipid production [7.47 and 2.89mg/(L·d), respectively]; CO2 supply volume at 6000mL/d for the growth rate [9.88mg/(L·d)], and at 4000mL/d for the lipid production [3.86mg/(L·d)]. In this experiment, the lipid production in the optimal conditions is significantly higher than the control group.