Patent ID: 8206954
Filing Date: 2012-06-26
Classification: C12N,C12P,C12Y

Abstract:
1. A method for producing an L-amino acid comprising: A) culturing a bacterium which belongs to the family Enterobacteriaceae and is able to produce an L-amino acid in a medium, and B) collecting the L-amino acid from the medium or the bacterium, wherein the bacterium has been modified so that the native activity of glucose dehydrogenase, which uses pyrroloquinoline quinone as a coenzyme, is reduced as compared to an unmodified bacterium, wherein the glucose dehydrogenase activity is reduced by decreasing expression of a gcd gene on the bacterium's chromosome, by a method selected from the group consisting of: a) inserting a transposon sequence into the coding region of the gcd gene so that the expression is disrupted, b) deleting all or a part of an expression control sequence of the gene, c) inserting one or more nucleotides into an expression control sequence of the gene so that the expression control sequence is no longer functional, d) deleting a part of or the entire gcd gene on the chromosome, and e) introducing a mutation selected from the group consisting of an amino acid substitution, a stop codon, and a frame shift mutation into the coding region of the gene on the chromosome so that the expression is disrupted, and f) combinations thereof.