响应面法优化海洋细菌MP-2酯酶发酵条件

Optimization of Fermentation Conditions for Marine Bacillus licheniformis MP-2 Esterase by Response Surface Methodology

采用响应面法(Response surface methodology)对海洋细菌MP-2酯酶的发酵条件进行了优化.首先采用了Plackett-Burman方法对影响酯酶发酵的因素进行评价,筛选出了3个显著因素为豆饼粉、花生粕和种龄,并利用DesignExpert7.0.3软件完成RSM法对显著性因素的进一步优化从而确定最佳条件.当花生粕0·9%;豆饼粉2·29%;接种量5·98%时,此时预测的最大酯酶活力为334·46U/mL.在最佳发酵条件下,优化后该酯酶活力由258·8U/mL提高到318·2U/mL.实际酶活力达到理论预测值的95%,十分接近.

Response Surface Methodology was used to study the optimal conditions of fermentation of marine MP-2 esterase. Firstly, A Plackett-Burman design was undertaken to evaluate the eleven factors related to Bacillus licheniformis MP-2 esterase fermentation. Peanut cake, soybean cake and inoculating ratio with great influence on the MP-2 esterase fermentation were chosen. Secondly, a response surface methodology （Box-Behnken） was used to further study the three influence factors, to optimize the above critical internal factors, and to find out the optimal central levels and the relationships among these factors by Design Expert 7.0.3. By solving the quadratic regression model equation and analyzing the response surface contour plots, the optimal process conditions were determined, that is, peanut cake, soybean cake, inoculating ratio were 0. 9%, 2. 29%, 5.98% , respectively. The maximum predicted activity of MP-2 esterase was verified as 334.46 U/mL under these conditions and the enzyme activity was practically improved from 258.8 U/mL to 318.2 U/mL after the optimization. The actual MP-2 esterase activity approached almost 95% of the theoretical predicted value. Fig 3, Tab 5, Ref 18