Patent ID: 8008048

Claim:
A method for producing a compound selected from the group consisting of L-cysteine, L-cystine, a derivative thereof, and combinations thereof, which comprises culturing a bacterium belonging to the family Enterobacteriaceae in a medium and collecting the compound from the medium, wherein said bacterium has L-cysteine-producing ability and has been modified to decrease the expression of the protein encoded by the yhaM gene as compared to the corresponding unmodified bacterium, wherein said expression is decreased by disrupting the yhaM gene, and wherein, prior to modification, the protein is selected from the group consisting of: (A) a protein comprising the amino acid sequence of SEQ ID NO: 2, and (B) a protein comprising the amino acid sequence of SEQ ID NO: 2 but which includes substitutions, deletions, insertions, or additions of one to 10 amino acid residues, and wherein L-cysteine-producing ability of the bacterium is improved as compared to the corresponding unmodified bacterium.