重组毕赤酵母产植酸酶发酵条件的优化

Optimization of phytase production by recombinant Pichia pastoris

为研究优化毕赤酵母工程菌H311产植酸酶的发酵条件,采用单因素试验和L18(37)正交试验考察不同工艺条件对产酶活性的影响。结果表明:影响重组毕赤酵母产植酸酶的因素重要性从大到小依次为诱导时间、甲醇添加量、装液量、初始诱导p H、生长时间、接种量和初始生长p H,产酶最佳条件为接种量3%(体积分数)、装液量20 m L(250 m L摇瓶)、生长时间20 h,诱导时间120 h、甲醇添加量1.5%(体积分数)、生长p H 6.0、诱导p H 5.0,在此条件下进行诱导表达,植酸酶的比酶活可达334 U/m L。

To optimize the condition for fermentation of phytase production by recombinant Pichia pastoris H311. The effects of inoculum,liquid volume,growth time,induction time,methanol concentration,initial growth pH and initial induction pH on expression of phytase in recombinant P-pastoris H311were studied by single factor experiment and L18 （ 3^7 ） orthogonal experiment. Recombinant phytase was then characterized. The influencing factors on the expression of phytase were in the following order：induction time,methanol concentration, liquid volume, the initial induction pH value, growth time, inoculum and initial growth pH value. The optimal condition was with 3%（v/v） inoculum,20 mL liquid volume（250 mL flask） ,20 h growth time,120 h induction time,1.5%（ v/v） methanol concentration,initial growth pH 6.0 value and initial induction pH 5.0. Under the optimal condition,the recombinant phytase reached an activity of 334 U/mL.