Screening for Lipase-producing Bacterial Strains and Optimization of the Fermentation Conditions

15 lipase-producing bacterial strains were isolated from 27 soil samples rich in oil and D9-1 was selected as the most potential lipase-producing strain through comparing the lipase activity in fermentation broths of these strains.The results showed that the optimum nitrogen source is peptone,optimum carbon source is 1% olive oil,optimum surfactant is 1% OP-10,optimum temperature is 30℃,and when the rotating speed was 170 r/min,the lipase activity in fermentation broth reached the highest after 24 h.