Abstract: BG-11 was used as the basic medium to establish different culture systems for Chlorella pyrenoidosa culture by adding and replacing different carbon and nitrogen sources, changing the proportion of carbon and nitrogen sources, removing phosphorus or sulfur and adding additional plant growth regulator, and the effects of various factors on the growth and oil production rate of Chlorella pyrenoidosa were investigated. The results showed that the growth and oil production rate of Chlorella pyrenoidosa were better than those of Chlorella vulgaris in both autotrophic and heterotrophic systems. The oil production rates of the two Chlorella species in the heterotrophic system were 20.14% and 18.66%, respectively. When glucose was used as the carbon source, the growth of Chlorella pyrenoidosa was the best and the oil production rate was the highest, and the oil production rate was 26.40%. When the nitrogen source was urea, the maximum oil production rate of Chlorella pyrenoidosa was got, and was 32.70%. The highest oil production rate of Chlorella pyrenoidosa was 34.42% when the carbon-nitrogen ratio was 30∶1. The oil production rate of Chlorella pyrenoidosa under sulfur deficiency increased by 28.54 percentage points compared with the control. Under the interference of jasmonic acid with the concentration of 1.5 mg/L, the oil production rate of Chlorella pyrenoidosa was the highest, which was 40.42%. The results indicated that the growth and oil production rate of Chlorella pyrenoidosa were better than those of Chlorella vulgaris; glucose was the best carbon source; urea was the best nitrogen source; the oil production rate was the highest when the carbon nitrogen ratio was 30∶1; sulfur deficiency had a greater effect on Chlorella pyrenoidosa; the oil production rate of Chlorella pyrenoidosa was the highest under the interference of jasmonic acid with a concentration of 1.5 mg/L.

Key words: Chlorella pyrenoidosa, carbon source, nitrogen source, plant growth regulator, oil production rate