Patent ID: 7300776

Claim:
A method for producing an L-amino acid selected from the group consisting of L-tryptophan, L-phenylalanine, L-lysine, L-tyrosine, L-glutamic acid, L-histidine, L-cysteine, and L-proline, comprising culturing in a medium a modified Escherichia coli K12 strain, MG1655 strain, W3110 strain, or SV164 strain, wherein said strain has an ability to grow in a medium containing 20 mg/L of L-valine, and collecting said L-amino acid from the medium or the strain, wherein said strain is modified so as to produce active acetohydroxy acid synthase II, wherein said active acetohydroxy acid synthase II is encoded by the E. coli ilvG gene in which a mutation is made at one or more positions corresponding to positions 982 to 984 of SEQ ID NO: 1 or at one or more positions upstream of these positions, wherein said mutation results in a frameshift of said ilvG gene.