The fermentation conditions of recombinant E.coli for producing carbonyl reductase were optimized.Firstly,peptone,yeast extract,glycerol and phosphate were screened to be the key components by Plackett-Burman design.Secondly,the steepest ascent design was operated to approach the optimal response.Thirdly,to evaluate the relationships between responses and the identified key components,mathematical models were developed by Box-Behnken design.Finally,the desirability function was used to find the best compromise between the two responses (carbonyl reductase activity and A600nm) based on the mathematical models constructed in Box-Behnken design.The optimal concentration was located to be 15.99 g/L peptone,31.06 g/L yeast extract,105.37 mmol/L phosphate,4.66 mL/L glycerol,0.4 g/L NaCl,0.2 g/L MgSO4,inoculation of 1％ and induction time of 8 h.After the validated experiment under such conditions,the production of carbonyl reductase was improved by 65％.%以实验室构建的产羰基还原酶的重组大肠杆菌为出发菌株,以菌体生长(A600nm)和羰基还原酶比活为响应值,对重组大肠杆菌产羰基还原酶的发酵条件进行优化.首先采用Plackett-Burman设计筛选出了4个关键影响因子:蛋白胨、酵母粉、磷酸盐和甘油;随后以Box-Behnken中心组合设计分别建立上述4个影响因子对A600nm和羰基还原酶比活的数学模型;最后通过满意度函数获得最佳发酵条件为:蛋白胨15.99 g/L,酵母粉31.06g/L,磷酸盐105.37 mmol/L,甘油4.66 mL/L,NaCl 0.4g/L,MgSO40.2 g/L,接种量1％以及诱导时间8h.在此优化条件下,重组大肠杆菌产羰基还原酶和菌体生长能力得到了较大的提升,羰基还原酶比活由优化前的1.031 U/mg提高到了1.706 U/mg,提高了65％.
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