L-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. By 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 imp...