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

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

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。

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 charhcteristics, 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-1Tween-80,0.5 g.L-1 MgSQ and2g.L-1 K：HPO4 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.