Abstract: The gene encoding urethanase (UH) from Lysinibacillus fusiformis SC02 was firstly cloned and expressed in Bacillus subtilis WB600. Production of UH was optimized based on single factor experiments and response surface analysis at shake flask level, resulting in its yield of 14.20 U/mL. The composition of optimal culture medium was determined as: starch 10 g/L, K2HPO4 9 g/L, malt extract 25 g/L, MgS04 1 g/L and trypone 55 g/L. The optimal fermentation temperature and inoculum amount were 37℃ and 4%(j), respectively. Enzyme production of recombinant bacteria in a 3 L fermenter showed that after 16 h, enzyme activity reached the highest titer 18.03 U/mL.

Key words: urethanase, Bacillus subtilis, culture medium, fermentation, response surface

摘要： 将来源于赖氨酸芽孢杆菌SC02的氨基甲酸乙酯水解酶(UH)基因在枯草芽孢杆菌Bacillus subtilis WB600中进行克隆和表达，在枯草芽孢杆菌中实现了UH活性表达，在摇瓶水平通过单因素考察和响应面分析实验对氨基甲酸乙酯水解酶发酵进行优化. 结表明，酶活最高可达到14.20 U/mL，产酶最佳培养基成分为：淀粉10 g/L、磷酸氢二钾9 g/L、麦芽浸膏25 g/L、硫酸镁1 g/L、胰蛋白胨55 g/L，最适发酵温度为37℃，最佳接种量4%. 在3 L发酵罐中采用最优发酵条件，酶活在16 h达到18.03 U/mL.

关键词: 氨基甲酸乙酯水解酶, 枯草芽孢杆菌, 培养基, 发酵, 响应面