产耐温蛋白酶苏云金芽孢杆菌FS140液体发酵条件优化

Optimization of Liquid-state Fermentation for Thermophilic Protease Production by Bacillus thuringiensis FS140

应用快速有效的数学统计方法对苏云金芽孢菌FS140耐温蛋白酶的发酵条件进行优化.首先采用二水平Plackett-Burman设计对影响产酶的8因素进行筛选,获得培养基成分中3个重要影响的因子:黄豆饼粉、酵母粉、葡萄糖;再利用响应面分析法对该3个因素进行3水平的优化,获得它们的最佳组合:黄豆饼粉1.8%、酵母粉0.36%、葡萄糖0.14%.优化后产酶水平达到837.71U mL-1,与响应面数学模型的预测值只有1.34%的误差.同时进行了发酵温度、初始pH、摇瓶装量与接种量等发酵条件的优化,FS140最终发酵产酶水平达918.91U mL-1.

Statistical methods were used to optimize the fermentation conditions for thermophilic protease production by Bacillus thuringiensis FS140. A Plackett - Burman design was used to select 3 important factors from 8 impact factors which affected protease fermentation. They were bean cake meal, yeast powder and glucose in culture medium. The optimum components obtained by the response surface methodology （RSM） were bean cake meal 1.8%, yeast powder 0. 36% and glucose 0. 14%, respectively. After the optimization, the yield of thermophilic protease increased markedly compared with the initial and reached 837.71 U/mL, of which only 1.34% differed from the forecast by RSM. After the optimization of fermentation conditions including fermentation temperature, initial pH, loading volume of medium and inoculation volume, the protease production reached 918.91 U/mL.