中文摘要：

枯草芽孢杆菌Bacillus subtilis 168是一株安全生产的菌株,但是在2,3-丁二醇（2,3-BD）的发酵过程中,会积累较多的副产物乙偶姻（AC）。乙偶姻还原酶是催化AC合成2,3-BD的关键酶。为了提高2,3-BD合成效率,首先将乙偶姻还原酶基因acr克隆到B.subtilis 168,构建了重组菌B.subtilis 168/p MA5-acr。对重组菌进行摇瓶发酵实验,结果表明,相比出发菌,重组菌的2,3-BD产量和转化率分别提高28.62%和22.87%,主要副产物AC积累量下降了20.01%。同时,分支路径的副产物甲酸、乙酸、乳酸、琥珀酸,也有不同程度的降低。

英文摘要：

Bacillus subtilis 168 is a safe strain for industrial-scale microbial production of 2,3-butanediol（2,3-BD）. However, a large quantity of by-product of acetoin（AC） is accumulated during 2,3-BD fermentation process. Acetoin reductase（ACR） is the key enzyme which catalyzes the conversion of acetoin to 2,3-BD. In this study,in order to improve 2,3-BD production,we firstly cloned the acr gene of acetoin reductase into B. subtilis 168,and then further constructed the recombinant strain B. subtilis 168/p MA5-acr. The results showed that the yield and conversion rate of the 2,3-BD were increased up to 28.62% and 22.87% by the recombinant strain,respectively.Whereas the accumulation of the main by-product of acetoin decreased by 20.01%. Furthermore,the molar yields of by-products of formic acid,acetic acid,lactic acid,and succinate were also decreased.