瓜氨酸生产相关基因簇在谷氨酸棒杆菌中的组成型表达

构建1种组成型载体并将载体应用在表达瓜氨酸相关基因簇argCJBDF上。通过去除pXMJ19诱导型启动子上游阻遏蛋白lacI基因的方法,构建组成型质粒pXMJ19-lacI,并将谷氨酸棒杆菌中合成瓜氨酸途径的基因簇argCJBDF克隆到改造过的组成型载体中,实现瓜氨酸合成相关基因簇argCJBDF在谷氨酸棒杆菌的组成型表达。结果表明:重组菌在30℃摇瓶发酵72 h后,N-乙酰谷氨酸激酶的酶活达到(0.323±0.015)U/mg,瓜氨酸的产量达到4.33 g/L。成功构建的组成型表达载体,实现了外源基因簇argCJBDF在谷氨酸棒杆菌中的组成型表达。

Constitutive expression of citrulline biosynthetic genes in Corynebacterium glutamicum

A recombinant constitutive expression vector was constructed and used to express a cluster of biosynthetic citrulline genes argCJBDF in Corynebacterium glutamicum.The constitutive expression vector PXMJ19-lacI was constructed by removing the lacI gene coding for lac repressor protein upstream of the inducible promoter.The biosynthetic tandem citrulline gene argCJBDF from C.glutamicum was inserted into the reconstructed constitutive vector,and was expressed in C.glutamicum without induction.Results showed that fermentation of the recombinant strains in shake-flask at 30 ℃ for 72 h demonstrated that N-acetylglutamate kinase activity and citrulline production reached(0.323±0.015) U/mg and 4.33 g/L.A recombinant constitutive expression vector was constructed,while an exogenous gene cluster argCJBDF was expressed in C.glutamicum.