Enhanced S-adenosyl-L-methionine synthesis in Saccharomyces cerevisiae using metabolic engineering strategies

• Published in: Biochemical engineering journal 2024-12, Vol.212, p.109504, Article 109504
• Main Authors: Wang, Yuanshan, Wang, Jinhao, Huang, Zuoyu, Tan, Liangzhuang, Zhang, Yuehan, Hu, Zhongce, Liu, Zhiqiang, Zheng, Yuguo
• Format: Article
• Language: English
• Subjects: CRISPR-Cas9; Metabolic engineering; S-adenosyl-L-methionine; Saccharomyces cerevisiae CEN.PK2–1C; Strategy portfolio
• ISSN: 1369-703X
• DOI: 10.1016/j.bej.2024.109504

S-adenosyl-L-methionine (SAM) plays pivotal roles in various physiological processes. With its increasing application in the treatment of diseases such as liver disease, depression, osteoarthritis and Alzheimer's, interest in SAM production aroused. Currently, Saccharomyces cerevisiae is the main industrial producer of SAM. With the surge in demand for SAM, improving the SAM biosynthesis is of importance. In this study, a multimodule engineering strategy was employed to improving SAM production: 1) Enhancing the gene expression of the sulfur assimilation pathway; 2) Strengthening the metabolic flux of the SAM synthesis pathway; 3) Weakening the SAM degradation pathway; 4) Increasing ATP supply. The resulting engineered mutant SC06 (S. cerevisiae CEN.PK2–1CΔgal80∷Tcyc1-sam2-Pgal1-Pgal10-met14-Tadh1, Δlsc2∷Tcyc1-hom6-Pgal1-Pgal10-met6-Tadh1, Δsah1Δmls1) displayed the highest SAM titer of 240.86 mg/L, which was 10.22-fold increase compared with the original strain. With optimized conditions, the SAM titer of mutant SC06 in shake flask fermentation reached 473.02 mg/L with a specific yield of 127.18 mg/g dry cell weight (DCW). In a 5 L fermenter with fed-batch fermentation, the maximal SAM yield of mutant SC06 reached 1.25 g/L with a specific yield of 166.67 mg/g DCW after 58 h cultivation. Therefore, the established metabolic engineering strategies displayed promising efficiency in improving the SAM productivity of S. cerevisiae CEN.PK2–1C, which may provide a useful tool for the improvement of SAM-producing strains. [Display omitted] •Overexpressing met14 gene of the sulfur assimilation pathway elevates SAM synthesis.•Disrupting TCA cycle enhances metabolic flux into the SAM synthesis pathway.•Knockout of sah1 gene inhibits SAM consumption and benefits SAM accumulation.•Knockout of mls1 gene elevates acetyl-CoA level and enhances ATP supply for SAM.•SAM biosynthesis markedly elevated with the metabolic engineering strategies.