食品科学 ›› 2022, Vol. 43 ›› Issue (6): 81-88.doi: 10.7506/spkx1002-6630-20210220-219

• 生物工程 • 上一篇    下一篇

高效合成L-高丝氨酸大肠杆菌基因工程菌株的构建

张宇,夏利,林蓓蓓,张稳杰,徐皓然,张成林   

  1. (天津科技大学生物工程学院,天津 300457)
  • 出版日期:2022-03-25 发布日期:2022-03-28
  • 基金资助:
    国家自然科学基金青年科学基金项目(31300069);中国博士后科学基金项目(2017M61170;2018T110662)

Construction of Escherichia coli Chassis for Efficient Production of L-Homoserine

ZHANG Yu, XIA Li, LIN Beibei, ZHANG Wenjie, XU Haoran, ZHANG Chenglin   

  1. (College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China)
  • Online:2022-03-25 Published:2022-03-28

摘要: 针对现有L-高丝氨酸生产菌株因营养缺陷需在发酵过程中添加L-苏氨酸等物质的问题,以大肠杆菌为底盘细胞,构建1?株非营养缺陷型L-高丝氨酸高产菌株。首先通过下调thrB和thrC的转录弱化L-高丝氨酸的降解途径;并过表达thrA、ppc和pntAB以强化L-高丝氨酸合成代谢流、提高前体物以及辅酶供应;在此基础上过表达rhtA增强L-高丝氨酸输出。获得的菌株H-10经5?L发酵罐发酵48?h,L-高丝氨酸产量达到52.1?g/L,转化率为43%(以占葡萄糖质量计),均高于现有报道。

关键词: L-高丝氨酸;代谢工程;大肠杆菌;外排

Abstract: Nutrients such as L-threonine need to be added during the fermentation of L-homoserine by auxotrophic strains. In this study, a non-auxotrophic Escherichia coli chassis for the high-yield production of L-homoserine was constructed. The expression of thrB and thrC were down-regulated to attenuate the degradation of L-homoserine; then the overexpression of thrA, ppc and pntAB was performed to reinforce the synthetic flux and improve precursor supply and NADPH generation; finally, rhtA was overexpressed to elevate L-homoserine efflux. After 48 h fermentation in a 5 L fermenter, the constructed strain H-10 produced 52.1 g/L of L-homoserine with a percentage transformation of glucose of 43%, which is higher than the values reported in the literature.

Key words: L-homoserine; metabolic engineering; Escherichia coli; efflux

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