Abstract:

A stain C1 with high ability to produce lipase was isolated from soil and identified as Burkholderia cepacia. In order to improve the production of lipase, some fermentation conditions were optimized. The optimal carbon source and nitrogen source were determined to be bran and peptone according to single-factor experiments, respectively. Three key factors such as bran, peptone and liquid volume were selected out of eleven factors affecting lipase production by Plaekett-Burman design, and were further optimized by Box-Behnken design and response surface methodology. A maximum lipase activity of 89.65 U/mL was obtained after 72 h fermentation of 30 mL of a fermentation medium composed of wheat bran 1.50 g/100 mL, peptone 1.05 g/100mL, olive oil 1.63 g/100 mL, K2HPO4 0.2 g/100 mL and MgSO4 0.05 g/100 mL at an initial pH of 7.0 with 180 r/ min shaking, which was 2.15 times higher than before optimization (28.50 U/mL).

Key words: lipase, Plackett-Burman design, response surface methodology, fermentation optimization