| The production conditions of lipase by Candida cylindracea were optimized. The best formular of the medium were obtained as follows: olive oil 6 g/L, yeast extract 9 g/L, tween-80 1%, CaCl20.5 g/L,K2HPO4 2 g/L,MgSO4·7H2O2 g/L, natural pH. The optimal fermentation conditions were obtained as follows: initial pH of medium 5.2, cultural time 25 h, speed of shaker 150 r/min. Under the optimal conditions, the average activity of the lipase produced by Candida cylindraceawas （15.00±0.05）U/mL after fermentation for 5 batches and the relative standard deviation was 2.34%, which had an ideal repeatability. The Candida cylindracea strain lived in acid environment and the production efficient of lipase was the best at pH 5.2, therefore, it was inferred that the lipase was acid lipase, which would have a certain degree of resistance on free fatty acids from the hydrolysis of oils and fats. Moreover, the highest activity of lipase produced by Candida cylindracea could be achieved after it was fermented for 25 h, which had the items of short fermentation period, low cost and high unit time productivity of lipase, suitable for industrial production. |
