响应面法优化产低温脂肪酶工程菌Cl02的发酵条件

目的采用响应面法优化产低温脂肪酶工程菌Cl02的发酵条件。方法通过单因素试验考察培养基中酵母氮源含量、pH值、甘油含量和甲醇含量对酶活的影响,确定产酶的主要影响条件,在此基础上,根据Box-Benheken中心组合试验设计原理,采用三因素三水平的响应面分析法,综合考察各因子对低温脂肪酶酶活的影响,建立低温脂肪酶酶活的二次回归模型。结果培养基中酵母氮源含量、pH值和甲醇含量对酶活的影响显著。最适产低温脂肪酶条件为:酵母氮源含量7.3 g/L、pH 6.0、甲醇含量9.1 g/L,在此条件下,低温脂肪酶酶活可达42.25 IU/ml,比优化前(28.0 IU/ml)提高了50.9%。结论利用响应面法优化的发酵条件可显著提高工程菌的产酶能力,为规模化生产低温脂肪酶奠定了基础。

Optimization of condition for fermentation of recombinant Cl02 strain producing cold-adapted lipase by response surface methodology

Objective To optimize the condition for fermentation of recombinant Cl02 strain producing cold-adapted lipase by response surface methodology(RSM).Methods The effects of content of yeast as nitrogen source,pH value as well as glycerol and methanol contents in medium on enzyme activity were investigated by single-factor test,based on which the main influencing factors of enzyme production were determined.The effects of various factors on activity of cold-adapted lipase were evaluated by RSM of three factors at four levels according to Box-Benheken center combination test design principles,based on which a multivariate quadratic regression model was established.Results The content of yeast as nitrogen source,pH value and methanol content in medium showed significant effect on enzyme activity.The optimal content of yeast as nitrogen,pH value and methanol content for production of cold-adapted lipase were 7.3 g / L,6.0 and 9.1 g / L respectively.Under the optimal condition,the activity of cold-adapted lipase was 42.25 IU / ml,which increased by 50.9% as compared with that before optimization(28.0 IU / ml).Conclusion The optimization of fermentation condition by RSM increased the cold-adapted lipase-producing ability of recombinant strain significantly,which laid a foundation of industrial production of the enzyme.