中文摘要：

为了获得毕赤酵母生产凝乳酶的最佳发酵条件,分别从起始诱导OD600、甲醇诱导浓度以及p H等方面研究了P.pastoris GS115在3.6 L发酵罐中表达微小根毛霉来源凝乳酶的高密度发酵,以恒溶氧反馈调节补加甘油和甲醇检测流加控制器在线监测流加甲醇。结果表明,在重组P.pastoris GS115/p PIC9k-chy起始诱导,OD600和甲醇诱导体积分数分别为150和2.0%,诱导p H为5.0时,发酵96 h凝乳酶活达到最大,为1 870 SU/m L,此时对应的生产强度和产物得率均达到最高水平,分别为19.48 SU/（m L·h）和2.42 SU/m L,总蛋白质质量浓度为0.64 mg/m L,凝乳活性与蛋白质水解活性的比值（MCA/PA）为63.43。

英文摘要：

In order to obtain the optimal condition of chymosin fermentation,we observed the influence of initial inducing OD600,methanol concentration and p H on the high density fermentation process in 3.6 L fermentor of P. pastoris GS115/p PIC9k-chy. By using glycerol feeding strategy with DO control in high-density fermentation and maintained the residual methanol concentration constantly with a methanol sensor. The result showed that the optimum condition were listed as follows：the OD600 was 150,the methanol concentration was 2.0% and the p H was 5.0,then the highest chymosin activity（17 80 SU/m L）,the highest chymosin productivity（19.48 SU/（m L·h））and the highest yield of products（2.42 SU/m L）were achieved,the total protein content and the ratio of milk-clotting activity to proteolytic activity（MCA/PA） were determined to be 0.64 mg/m L,63.43.