Multivariate modular metabolic engineering for enhanced l-methionine biosynthesis in Escherichia coli

Biotechnology for Biofuels and Bioproducts

Research

Aihua Deng¹  Yun Zhang¹  Shuwen Liu¹  Jianjian Sun¹  Jiahui Sun²  Qian Liu³  Tingyi Wen⁴  Zhongcai Li⁵  Mingjie Li⁵ 

[1] State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China;State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China;College of Life Sciences, Hebei University, 071002, Baoding, China;State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China;National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China;State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China;Savaid Medical School, University of Chinese Academy of Sciences, 100049, Beijing, China;China Innovation Academy for Green Manufacture, Chinese Academy of Sciences, 100049, Beijing, China;State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China;University of Chinese Academy of Sciences, 100049, Beijing, China;

关键词: -Methionine;    Escherichia coli;    Metabolic engineering;    Multivariate modular;    Cystathionine γ-synthase;   

DOI  :  10.1186/s13068-023-02347-7

 received in 2023-03-03, accepted in 2023-05-23,  发布年份 2023

来源: Springer

【 摘 要 】

Backgroundl-Methionine is the only bulk amino acid that has not been industrially produced by the fermentation method. Due to highly complex and strictly regulated biosynthesis, the development of microbial strains for high-level l-methionine production has remained challenging in recent years.ResultsBy strengthening the l-methionine terminal synthetic module via site-directed mutation of l-homoserine O-succinyltransferase (MetA) and overexpression of metAfbr, metC, and yjeH, l-methionine production was increased to 1.93 g/L in shake flask fermentation. Deletion of the pykA and pykF genes further improved l-methionine production to 2.51 g/L in shake flask fermentation. Computer simulation and auxotrophic experiments verified that during the synthesis of l-methionine, equimolar amounts of l-isoleucine were accumulated via the elimination reaction of cystathionine γ-synthetase MetB due to the insufficient supply of l-cysteine. To increase the supply of l-cysteine, the l-cysteine synthetic module was strengthened by overexpression of cysEfbr, serAfbr, and cysDN, which further increased the production of l-methionine by 52.9% and significantly reduced the accumulation of the byproduct l-isoleucine by 29.1%. After optimizing the addition of ammonium thiosulfate, the final metabolically engineered strain MET17 produced 21.28 g/L l-methionine in 64 h with glucose as the carbon source in a 5 L fermenter, representing the highest l-methionine titer reported to date.ConclusionsIn this study, a high-efficiency strain for l-methionine production was derived from wild-type Escherichia coli W3110 by rational metabolic engineering strategies, providing an efficient platform for the industrial production of l-methionine.

【 授权许可】

CC BY   
© The Author(s) 2023

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