枯草芽孢杆菌ZC1发酵产中性蛋白酶的条件优化

Optimization of Fermentation Conditions for Neutral Protease Produced by Bacillus subtillis ZC1

在摇瓶发酵条件下,对枯草芽孢杆菌产中性蛋白酶条件进行优化。在单因素的基础上,通过Plackett-Burman实验和最徒爬坡实验确定出响应面实验设计的中心点:豆粕粉66g/L,麦芽糖16g/L及磷酸二氢钾8.5g/L。通过响应面实验设计,得到最佳发酵条件为:豆粕粉67.13g/L,麦芽糖16.17g/L,磷酸二氢钾8.52g/L,吐温-80 3mL/L,海藻糖3g/L,pH 7.5,接种量4%,温度37℃。在该发酵条件下发酵72h,中性蛋白酶酶活由原来的454.2U/mL提高到993.1U/mL。

By shake flask fermentation,the fermentation conditions for neutral protease produced by Bacillus subtilis ZC1 are optimized.According to single factor experiment,the center point of experimentaldesign of response surface is as follows：soybean meal of 66 g/L,malt sugar of 16 g/L and KH2PO4 of 8.5 g/L by the results of Plackett-Burman and the steepest ascent path design.On the basis of the results of response surface experimental design,the optimal fermentation conditions are as follows：soybean meal of 67.13 g/L,malt sugar of 16.17 g/L,KH2PO4 of 8.52 g/L,Twain-80 of 3 mL/L,trehalose of 3 g/L,pH of 7.5,inoculum size of 4%,cultural temperature of 37 ℃.The activity of neutral protease is increased from 454.2 U/mL to 993.1 U/mL at the optimal fermentation conditions for 72 h of fermentation.