Method for producing L-amino acid using a microorganism with decreased aspartate aminotransferase activity
View Patent ↗According to the present invention, a process for producing an amino acid using a microorganism in which aspartate aminotransferase activity is decreased or deleted, and which has the capability of producing and accumulating the amino acid is provided.
1. A process for producing an L-amino acid which comprises:
culturing in a medium a mutant Escherichia coli ( E. coli ) microorganism, wherein the mutant E. coli microorganism comprises a substitution, deletion, or addition of one or more bases in a gene encoding aspartate aminotransferase as compared to the gene encoding aspartate aminotransferase in a parental E. coli microorganism, and wherein aspartate aminotransferase activity of the mutant E. coli microorganism is absent as compared to the aspartate aminotransferase activity of the parental microorganism,
producing and accumulating the L-amino acid in the medium, wherein the mutant E. coli microorganism produces a greater amount of the L-amino acid than the parental E. coli microorganism under the same culture conditions, and
collecting the L-amino acid from the medium, wherein the L-amino acid is selected from L-glutamine, L-proline, L-ornithine, L-citrulline, L-arginine, and L-hydroxyproline,
wherein the aspartate aminotransferase in the parental E. coli microorganism is a protein
consisting of the amino acid sequence shown in SEQ ID NO: 2.
2. The process of claim 1 , wherein the aspartate aminotransferase in the parental E. coli microorganism is encoded by a DNA
consisting of the nucleotide sequence shown in SEQ ID NO: 1.