Method of producing L-amino acids

A method for producing an L-amino acid comprising:

• (i) cultivating in a culture medium an L-amino acid-producing bacterium belonging to the family Enterobacteriaceae to produce and accumulate the L-amino acid in the culture medium, cells of the bacterium, or both, and
• (ii) collecting the L-amino acid from the culture medium, the cells, or both,
• wherein said bacterium has been modified to overexpress a gene encoding a periplasmic adaptor protein;
• wherein said gene is selected from the group consisting of:
• (A) yibHI gene;
• (B) a gene comprising the nucleotide sequence of SEQ ID NO:
• 1;
• (C) a gene comprising a nucleotide sequence that is able to hybridize under stringent conditions with a nucleotide sequence complementary to the sequence of SEQ ID NO:
• 1;
• wherein the stringent conditions are washing 2 times with a salt solution of 0.1×SSC, 0.1% SDS at 60° C.;
• and wherein if the gene is overexpressed in the bacterium, the amount of the L-amino acid produced by the bacterium is increased as compared to that in a bacterium not modified to overexpress a gene encoding a periplasmic adaptor protein;
• (D) a gene having an identity of not less than 90% with respect to the entire nucleotide sequence of SEQ ID NO:
• 1;
• and wherein if the gene is overexpressed in the bacterium, the amount of the L-amino acid produced by the bacterium is increased as compared to that in a bacterium not modified to overexpress a gene encoding a periplasmic adaptor protein;
• (E) a gene comprising the variant nucleotide sequence of SEQ ID NO:
• 1, wherein the variant nucleotide sequence is due to the degeneracy of the genetic code;
• (F) a gene encoding a protein comprising the amino acid sequence of SEQ ID NO:
• 2;
• and wherein if the gene is overexpressed in the bacterium, the amount of the L-amino acid produced by the bacterium is increased as compared to that in a bacterium not modified to overexpress a gene encoding a periplasmic adaptor protein;
• (G) a gene encoding a protein comprising the amino acid sequence of SEQ ID NO:
• 2, but wherein said amino acid sequence includes substitution, deletion, insertion, and/or addition of one to ten amino acid residues;
• and wherein if the gene is overexpressed in the bacterium, the amount of the L-amino acid produced by the bacterium is increased as compared to that in a bacterium not modified to overexpress a gene encoding a periplasmic adaptor protein;
• and
• (H) a gene encoding a protein comprising the amino acid sequence having an identity of not less than 90% with respect to the entire amino acid sequence SEQ ID NO:
• 2;
• and wherein if the gene is overexpressed in the bacterium, the amount of the L-amino acid produced by the bacterium is increased as compared to that in a bacterium not modified to overexpress a gene encoding a periplasmic adaptor protein.