弹性蛋白酶产生菌的诱变选育及其发酵条件初步研究

Study on Breeding and Fermentation Conditions of An Elastase-producing Strain

以弹性蛋白酶产生菌芽孢杆菌Bacillus sp．EA9为出发菌株，经离子注入和紫外线复合诱变，筛选到弹性蛋白酶高产菌株，编号为EA9314。用单因子条件试验、Plackett—Burman试验及正交试验对该菌株进行培养基组成及培养条件的初步研究，结果表明：其最佳培养基组成是：2％葡萄糖，1．5％酵母粉，0．1％豆饼粉，0．1％K2HPO4，0．01％MgSO4；最佳培养条件是：起始pH6．5～7．0，250ml三角瓶装液量20ml，接种量6％。在此发酵条件下，该菌产酶水平为274．7U／ml。

An elastase high-yield strain EA9314 was screened from Bacillus sp. EA9 through ion beam and UV treatment. Its fermentation conditions were studied. The experimental results showed that the optimal medium was consisted of 2 % glucose, 1.5 % yeast extract, 0.1% soybean flour, 0.1% K2HPO4 and 0.01% MgSO4, among which, glucose and yeast extract were the most important factors. The optimal culture conditions were as follows： initial pH 6.5 - 7.0, medium cubage 20ml/ 250ml, inoculum size 6%. In optimum condition, it had the highest elastase production of 274.7 U/ml.