Open AccessBiosynthesis of L ‐5‐methyltetrahydrofolate by genetically engineered Escherichia coli
Author(s) -
Wang Yubo,
Zhang Meng,
Li Lexin,
Yi Jihong,
Liang Jiyu,
Wang Shuning,
Xu Ping
Publication year - 2022
Publication title -
microbial biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.287
H-Index - 74
ISSN - 1751-7915
DOI - 10.1111/1751-7915.14139
Subject(s) - escherichia coli , biochemistry , metabolic engineering , formate dehydrogenase , reductase , biosynthesis , methionine synthase , biology , methylobacterium , metabolic pathway , enzyme , dihydrofolate reductase , chemistry , methionine , cofactor , gene , amino acid , 16s ribosomal rna
L ‐5‐Methyltetrahydrofolate ( L ‐5‐MTHF) is the only biologically active form of folate in the human body. Production of L ‐5‐MTHF by using microbes is an emerging consideration for green synthesis. However, microbes naturally produce only a small amount of L ‐5‐MTHF. Here, Escherichia coli BL21(DE3) was engineered to increase the production of L ‐5‐MTHF by overexpressing the intrinsic genes of dihydrofolate reductase and methylenetetrahydrofolate (methylene‐THF) reductase, introducing the genes encoding formate‐THF ligase, formyl‐THF cyclohydrolase and methylene‐THF dehydrogenase from the one‐carbon metabolic pathway of Methylobacterium extorquens or Clostridium autoethanogenum and disrupting the gene of methionine synthase involved in the consumption and synthesis inhibition of the target product. Thus, upon its native pathway, an additional pathway for L ‐5‐MTHF synthesis was developed in E. coli , which was further analysed and confirmed by qRT‐PCR, enzyme assays and metabolite determination. After optimizing the conditions of induction time, temperature, cell density and concentration of IPTG and supplementing exogenous substances (folic acid, sodium formate and glucose) to the culture, the highest yield of 527.84 μg g −1 of dry cell weight for L ‐5‐MTHF was obtained, which was about 11.8 folds of that of the original strain. This study paves the way for further metabolic engineering to improve the biosynthesis of L ‐5‐MTHF in E. coli .