大肠杆菌工程菌mglB基因的敲除及水稻秸秆水解液发酵L-丙氨酸  

The Knockout of mglB Gene of Escherichia coli Engineering Strain and L-alanine Fermentation with Rice Straw Hydrolysate

作　　者：王灿 潘海亮 梁泉喜 王永泽[1] 王金华[1] WANG Can;PAN Hai-liang;LIANG Quan-xi(Key Laboratory of Fermentation Engineering of Ministry of Education,Hubei University of Technology,Wuhan,Hubei 430068;Huakang Mengzhiyuan Biotechnology Co.,Ltd.,Binzhou,Shandong 256600)

机构地区：[1]湖北工业大学发酵工程教育部重点实验室,湖北武汉430068 [2]华康梦之缘生物科技有限公司,山东滨州256600

出　　处：《安徽农业科学》2020年第7期113-117,共5页Journal of Anhui Agricultural Sciences

基　　金：国家“十二五”支撑计划(2012BAD27B03)。

摘　　要：[目的]通过mglB基因敲除进一步降低混合糖发酵时常存在的葡萄糖效应,提高水稻秸秆水解液发酵L-丙氨酸的效率。[方法]以大肠杆菌ptsG基因缺陷菌株JH-B3为出发菌,利用RED同源重组技术敲除葡萄糖转运基因mglB,构建ptsG和mglB双缺陷菌株JH-B6,分别以60 g/L葡萄糖、30 g/L木糖和水稻秸秆水解液为碳源进行发酵,验证mglB基因缺失对菌株利用葡萄糖、木糖和混合糖能力的影响。[结果]以60 g/L葡萄糖发酵时,JH-B6利用葡萄糖速率较JH-B3下降了19.9%;以30 g/L木糖发酵时,JH-B6利用木糖速率较JH-B3增加了23.5%;以水稻秸秆水解液发酵时,JH-B3发酵周期和糖酸转化率分别为128 h和89.5%,JH-B6发酵周期为88 h,较JH-B3缩短了31.3%,糖酸转化率为93.9%,较JH-B3提高了4.9%。[结论]双基因缺陷型菌株JH-B6在ptsG基因缺陷菌株JH-B3的基础上缺失mglB基因,进一步降低了葡萄糖效应,提高了水稻秸秆水解液发酵L-丙氨酸的效率。[Objective]The knockout of the mglB gene was preformed to reduce the glucose effect which often presents in the mixed sugar fermentation,which might improve the efficiency of L-alanine fermenting using the rice straw hydrolysate.[Method]Using the E.coli ptsG gene-deficient strain JH-B3 as the starting strain,the glucose transport gene mglB was knocked out by RED homologous recombination technology to construct ptsG and mglB double-deficient strain JH-B6,respectively,with 60 g/L glucose and 30 g/L xylose and rice straw hydrolysate was fermented as a carbon source respectively to verify the effect of the mglB gene deletion on the ability of the strain to utilize glucose,xylose and mixed sugar.[Result]When fermented with 60 g/L glucose,the glucose consumption of JH-B6 decreased by 19.9%compared with JH-B3.In the case of fermented with 30 g/L xylose,the xylose consumption of JH-B6 increased by 23.5%compared with JH-B3.When fermented with rice straw hydrolysate,the fermentation time and sugar conversion of JH-B3 were 128 h and 89.5%,respectively.The fermentation time of JH-B6 was 88 h,which was 31.3%shorter than JH-B3,and the sugar conversion of JH-B6 was 93.9%,an increase of 4.9%over JH-B3.[Conclusion]The deletion of mglB gene on the basis of ptsG gene-deficient strain JH-B3 further reduced the glucose effect and improved the fermentation efficiency of L-alanine in rice straw hydrolysate.

关 键 词：水稻秸秆 mglB基因 葡萄糖效应 L-丙氨酸 发酵 

分 类 号：S182[农业科学—农业基础科学]