Method for producing L-methionine

A method of producing L-methionine, comprising:

• culturing a microorganism selected from the group consisting of:
• Escherichia coli, Corynebacterium glutamicum, and Corynebacterium humireducens in a culture medium which, at the start of culturing, comprises L-homoserine and a sulphur source selected from the group consisting of:
• methyl mercaptan, a methyl mercaptan salt and dimethyl disulfide, wherein said culturing results in the accumulation of said L-methionine in said culture medium, and wherein:
• the microorganism has been genetically engineered to increase, compared to the microorganism prior to genetic engineering, the activity of:
• i) an enzyme having L-homoserine O-acetyltransferase activity and comprising the amino acid sequence of SEQ ID NO:2;
• and
• ii) an enzyme having O-acetyl-L-homoserine sulfhydrylase activity and comprising the amino acid sequence of SEQ ID NO:4;
• by increasing the copy number of nucleotide sequences encoding the enzymes and/or due to nucleotide sequences encoding the enzymes being in functional linkage to a promoter that increases expression of the enzymes;
• and
• during culturing, acetate formed as a result of conversion of O-acetyl-L-homoserine to L-methionine is reused by the microorganism that has been genetically engineered.