Burkholderia cepacia S31细菌高产位置非特异性脂肪酶的发酵条件优化

从油脂污染的土壤中分离获得了1株高效产脂肪酶的细菌S31,经鉴定为Burkholderia cepacia(洋葱伯克霍尔德菌)。B.cepacia S31所产脂肪酶具有活性高、耐高温、耐有机溶剂和位置非特异性水解甘油三酯等优良特性。为了进一步提高S31菌株的产酶量,对该菌产酶的发酵条件进行优化。通过单因子试验筛选出最佳碳源为麸皮,最佳氮源为蛋白胨,最佳诱导物为Tween-80。通过对培养基各组分及外部培养条件因素的正交试验,确定S31菌产脂肪酶的摇瓶发酵最优条件为:以20 g.L-1麸皮、10 g.L-1蛋白胨、40 g.L-1Tween-80、0.5 g.L-1MgSO4和2 g.L-1K2HPO4为培养基(pH 7.0),250 mL三角瓶装40 mL培养基,3%接种量,30℃、180 r.min-1培养66 h可获得最理想的酶产量,达283.6 U.mL-1,比优化前提高2.73倍。

Fermentation optimization for non-positional specificity lipase production of Burkholderia cepacia S31

A lipase-producing strain named S31 from the soil of a cole plantation was isolated,which was identified as Burkholderia cepacia.S31 lipase had a variety of highly desirable characteristics,such as high activity,temperature stability,organic solvents tolerance and hydrolysis of triglyceride without positional specificity.In order to enhance the enzyme productivity,the culture conditions were improved.Initially,single-factor experiments were used to evaluate the optimal carbon source,nitrogen source and inducer,which were bran,peptone and Tween-80,respectively.According to the orthogonal tests of media components and fermentation parameters,the optimal culture conditions were determined as follows:the culture medium containing of 20 g·L-1 bran,10 g·L-1 peptone,40 g·L-1 Tween-80,0.5 g·L-1 MgSO4 and 2 g·L-1 K2HPO4 with initial pH 7.0.The overnight culture was inoculated to 40 mL medium in 250 mL shaking flask,3% inocution amount,and fermented at 30 ℃ with 180 r·min-1 shaking for 66 h.The maximum lipase activity reached a high level(283.6 U·mL-1),which was improved 2.73 folds compared with that under the original conditions.The study offered foundation for large-scale production and application of S31 lipase.