采用响应面分析对苯丙氨酸解氨酶转化底物反式肉桂酸为苯丙氨酸的条件进行优化。首先采用Plackett-Burman试验筛选出对肉桂酸转化率影响的显著因素——底物浓度、Span60和聚乙二醇8000。利用最陡爬坡路径逼近区域。最后,应用Box-Behnken设计和响应面分析确定苯丙氨酸解氨酶转化底物反式肉桂酸为苯丙氨酸的最佳条件是:氨水浓度10mol/L、CTAB0.2mg/mL、Trition1003g/mL、卵磷脂4g/mL、谷氨酸钠5g/mL、Span6027.38mg/mL、PEG80002.74mg/mL、底物浓度11.93mg/mL。经过优化,转化率可达53.22%,比未优化前提高80%。

Response surface analysis was used to optimize the conditions in transformation of trans-cinnamic acid for PAL production by R. glutinis JM432. First,plackett-burman design was adopted to screen out the important factors affecting transformation:Span 60,PEG8000 and substrate concentration. Then,the path of the steepest ascent was utilized to approach the optimal region of transformation. At last,the optimal composition was obtained by Box-behnken design and response surface analysis. The optimal conditions of transformation were:Ammonia concentration 10 mol/L,CTAB 0.02%,Trition100 0.3%,Lecithin 0.4%,Sodium glutamate 0.5%,Span60 2.738%,PEG8000 0.274%,substrate concentration 1.193%.After optimization,the rate of transformation of trans-cinnamic acid was up to 53.22%,1.8 times higher than that in the original conditions.