Patent ID: 7223572

Claim:
An isolated strain of Methylophilus methylotrophus having L-lysine-producing ability, wherein dihydrodipicolinate synthase activity is enhanced as compared to a wild-type Methylophilus methylotrophus strain, and wherein said dihydrodipicolinate synthase is selected from the group consisting of: a) a protein encoded by a DNA comprising nucleotides 1268 to 2155 of SEQ ID NO:9; and b) a protein having dihydrodipicolinate synthase activity and encoded by a DNA comprising nucleotide numbers 1268 to 2155 of SEQ ID NO:9, except that substitution, deletion, or addition of one to 10 amino acids is present in the amino acid sequence of said protein, and wherein said activity is enhanced by a method selected from the group consisting of: i) increasing the copy number of said DNA in said strain, ii) placing multiple copies of said DNA on the chromosome of said strain, and iii) replacing a native promoter with a stronger promoter upstream of said DNA.