谷氨酸棒杆菌中L-半胱氨酸外排蛋白的鉴定及应用  

Identification and application of L-cysteine exporter from Corynebacterium glutamicum

作　　者：乔晋芳 杜焕敏 刘川 祁玉婷 吴硕 徐宁[2] 戴玉杰[1] 邵丽 刘君[2] QIAO Jinfang;DU Huanmin;LIU Chuan;QI Yuting;WU Shuo;XU Ning;DAI Yujie;SHAO Li;LIU Jun(College of Biotechnology,Tianjin University of Science and Technology,Tianjin 300457,China;Tianjin Institute of Industrial Biotechnology,Chinese Academy of Sciences,Tianjin 300308,China;College of Life Sciences,Northeast Agricultural University,Harbin 150038,China)

机构地区：[1]天津科技大学生物工程学院,天津300457 [2]中国科学院天津工业生物技术研究所,天津300308 [3]东北农业大学生命科学学院,黑龙江哈尔滨150038

出　　处：《食品与发酵工业》2023年第23期56-63,共8页Food and Fermentation Industries

基　　金：国家重点研发计划项目(2021YFC2100700)。

摘　　要：L-半胱氨酸是一种重要的含硫氨基酸,被广泛应用于食品,医药,化妆品等行业。有效的外排蛋白不仅可以降低反馈抑制和细胞毒性,还能提高菌体的生产能力。在细胞工厂的构建中发挥重要作用。该研究基于转录组测序分析,在谷氨酸棒杆菌中发现一种新的L-半胱氨酸外排蛋白Cg1298-Cg1299。当添加7.5 mmol/L L-半胱氨酸时,cg1298-cg1299缺失菌株的生长比对照菌株降低了约24.2%,而回补菌株恢复了对半胱氨酸的抗性。利用Cys-Tyr二肽进一步检测Cg1298-Cg1299对半胱氨酸的外排能力,发现cg1298-cg1299双敲菌株的L-半胱氨酸外排能力下降了26.3%。最后,在L-半胱氨酸底盘菌中过表达cg1298-cg1299使得L-半胱氨酸产量提高17.1%。综上所述,Cg1298-Cg1299是谷氨酸棒杆菌中一种新的L-半胱氨酸外排蛋白,其显著增强了谷氨酸棒杆菌对L-半胱氨酸的耐受性,并提高了L-半胱氨酸的生产能力,为将来构建高产L-半胱氨酸的细胞工厂提供了一个有效靶点。As an important sulfur-containing amino acid,L-cysteine is widely used in food,medicine,cosmetics,and other industries.Efficient transporters play an important role in the construction of cell factories,they not only reduce feedback inhibition and cytotoxicity,but also improve cell production capacity.In this study,a novel L-cysteine exporter,Cg1298-Cg1299,was discovered in Corynebacterium glutamicum by transcriptome analysis.When 7.5 mmol/L L-cysteine was added,the cell growth of cg1298-cg1299 deletion strain was 24.2%lower than that of the control strain,while the complemented strain recovered its resistance to L-cysteine.In addition,the cysteine efflux capacity of Cg1298-Cg1299 was further examined by a dipeptide Cys-Tyr addition assay,and the results revealed that the efflux capacity of the cg1298-cg1299 deletion strain for L-cysteine decreased by 26.3%compared to the control strain.Finally,the production of L-cysteine increased by 17.1%by overexpression of cg1298-cg1299.In summary,our results showed that Cg1298-Cg1299 was a novel L-cysteine exporter in C.glutamicum,which significantly improved the tolerance of C.glutamicum to L-cysteine and the production of L-cysteine,providing an effective target for constructing efficient cell factory to produce L-cysteine in the future.

关 键 词：L-半胱氨酸 谷氨酸棒杆菌 外排蛋白 转录组分析 Cg1298-Cg1299 

分 类 号：TQ922[轻工技术与工程—发酵工程]