重组凝乳酶摇瓶发酵条件的初步优化研究

凝乳酶是一种酸性蛋白酶,用作动物饲料添加剂,可提高动物特别是幼龄动物对饲料中蛋白成分的消化吸收率,促进其生长。本试验研究了由毕赤酵母胞外表达多拷微小毛霉凝乳酶的摇瓶发酵条件。确定最佳表达条件为：甲醇每24 h添加1.0%,无氨基酵母氮源培养基（YNB）添加1.5%,采用pH6.0的磷酸缓冲液,诱导120 h,在此条件下,重组凝乳酶的产量可达6 500 IU/ml。

Research on Optimum Fermentation Condition of Recombined Rennin

Rennin is a kind of acidic protease.For animals,especially young animals,adding rennin additive to their feedstuff can increase the digestive rate of protein component,and thus,accelerate their growth rates.Some of the optimized fermentation condition of recombined rennin was as follows: adding 1.5% yeast nitrogen base without amino acid(YNB);using phosphate buffer at pH 6.0;fermenting for 120 hours,and adding 1.0% methanol every 24 h.Under these conditions,the output of recombined rennin could be 6 500 IU/ml.