以甘油为碳源分批补料高密度发酵产环氧化物水解酶

Glycerol as a Carbon Source to Produce Epoxide Hydrolase by High Cell Density Fed-Batch Cultivation

环氧化物水解酶能够立体选择性地催化环氧化合物生成相应的二醇,具有重要的工业应用价值。通过摇瓶实验研究了不同甘油浓度对重组大肠杆菌Rosetta(DE3)/pET28(a)-CESH生长的影响,确定了IPTG最佳诱导时机、诱导浓度和诱导后培养温度。在15 L发酵罐进行放大培养,对比分批补料和批次发酵,前者生产率达6.71×105 U·(L·h)-1,比批次发酵提高了33.3%,酶活达到2.0×107 U·L-1,所用的时间,比批次发酵缩短了10 h,适合于工业应用。

Epoxide hydrolase is an important industrial enzyme which can stereo-selectively transform racemic epoxide into enantiomeric vicinal diol. In this study, the growth of E. coli Rosetta （DE3）/pET28（a）-CESH on different concentrations of glycerol was studied in shaking flask. Induction time, IPTG concentration and culture temperature after induction were optimized to enhance the production of CESH. The results reveal that in a 15 L fermentor, the fed-batch fermentation process can reduce the fermentation time by 10 hours. Compared with the batch fermentation process, the CESH productivity was increased by 33.3%during the whole process. These results indicate that the new process is suitable for industry application.