Engineering of Corynebacterium glutamicum to Enhance L-ornithine Production by Gene Knockout and Comparative Proteomic Analysis  

基因敲除谷氨酸棒杆菌提高鸟氨酸产量及比较蛋白质组学分析(英文)

作　　者：卢冬梅 刘建忠 毛宗万 

机构地区：[1]The Key Laboratory of Gene Engineering of Ministry of Education,State Key Laboratory of Biocontrol,Sun Yat-Sen University

出　　处：《Chinese Journal of Chemical Engineering》2012年第4期731-739,共9页中国化学工程学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China (30970089,20876181,20831006);the Natural Science Foundation of Guangdong Province (9351027501000003)

摘　　要：Engineered Corynebacterium glutamicum was constructed for L-ornithine production by disrupting genes of argF and proB to prevent the flux away from L-ornithine.Effect of the inactivation of 2-oxoglutarate de-hydrogenase complex(ODHC) on L-ornithine production was also investigated.It was found that the inactivation of ODHC by knockout of the kgd gene enhanced L-ornithine production.The engineered C.glutamicum ATCC13032(ΔargFΔproBΔkgd) produced L-ornithine up to 4.78 g·L-1 from 0.24 g·L-1 of the wild-type strain.In order to understand the mechanism of L-ornithine production in C.glutamicum ATCC13032(ΔargFΔproBΔkgd) and find out new strategies for further enhancing L-ornithine production,the comparative proteome between the wild-type and the engineered strain was analyzed.L-Ornithine overproduction in the engineered strain was related to the up-regulation of the expression levels of enzymes involved in L-ornithine biosynthesis pathway and down-regulation of the expression levels of proteins involved in pentose phosphate pathway.The overexpression of genes in the upstream pathway of glutamate to increase the availability of endogenous glutamate may further in-crease ornithine production in the engineered C.glutamicum and the ornithine synthesis enzymes(ArgCJBD) may not be the limiting enzymes in the engineered C.glutamicum.Engineered Corynebacterium glutamicum was constructed for L-ornithine production by disrupting genes of argF and proB to prevent the flux away from L-ornithine.Effect of the inactivation of 2-oxoglutarate de-hydrogenase complex（ODHC） on L-ornithine production was also investigated.It was found that the inactivation of ODHC by knockout of the kgd gene enhanced L-ornithine production.The engineered C.glutamicum ATCC13032（ΔargFΔproBΔkgd） produced L-ornithine up to 4.78 g·L-1 from 0.24 g·L-1 of the wild-type strain.In order to understand the mechanism of L-ornithine production in C.glutamicum ATCC13032（ΔargFΔproBΔkgd） and find out new strategies for further enhancing L-ornithine production,the comparative proteome between the wild-type and the engineered strain was analyzed.L-Ornithine overproduction in the engineered strain was related to the up-regulation of the expression levels of enzymes involved in L-ornithine biosynthesis pathway and down-regulation of the expression levels of proteins involved in pentose phosphate pathway.The overexpression of genes in the upstream pathway of glutamate to increase the availability of endogenous glutamate may further in-crease ornithine production in the engineered C.glutamicum and the ornithine synthesis enzymes（ArgCJBD） may not be the limiting enzymes in the engineered C.glutamicum.

关 键 词：L-ornithine production gene knockout 2-oxoglutarate dehydrogenase Corynebacterium glutamicum proteomic analysis 

分 类 号：TQ922[轻工技术与工程—发酵工程]