产中性蛋白酶菌株的筛选及其发酵条件的优化

Screening of a Neutral Protease Strain and Optimizing of Fermentation Conditions

从土壤样品中分离筛选出产一株中性蛋白酶产生菌ZH-6。经单因子试验、正交试验表明,该菌株摇瓶发酵产酶的最佳发酵周期48 h,发酵温度33℃,摇床转速为180 rpm。最佳发酵培养基为玉米淀粉2.0%,麸皮3.0%,Na2HPO4.12H2O 0.4%,KH2PO4 0.03%,ZnCl2 0.1%。起始pH 6.5的条件下,其酶活力为1 428.3 U/ml。

Neutral protease strain ZH-6 was isolated from soil sample. Single factor experiments and orthogonal experiments were conducted, and the results showed that under the conditions as follows： fermentation time 48 h, fermentation temperature 33℃, rotation speed 180 rpm, initial pH 6.5 with the fermentation culture medium （corn-starch 2.0%, wheat-bran 3.0%, Na2HPO4·12H2O 0.4%, KH2PO4 0.03%, ZnCl2 0.1%）, the protease activity was 1 428.3 U/ml.