# US 5,705,370 A · Process for producing L-amino acids by fermentation

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- Number: US 5,705,370 A
- Document ID: US5705370A
- Status: Granted
- Kind: A
- Application number: 08/440,467
- Filed: 1995-05-12
- Granted: 1998-01-06
- Earliest claimed: 1989-01-13
- Assignees: Ajinomoto Co., Inc.
- Inventors: Takayasu Tsuchida; Haruo Uchibori; Hiroshi Takeuchi; Mitsuyoshi Seki
- Web page: https://patentgrep.com/patent/US5705370A

## CPC

- C12P 13/04: Alpha- or beta- amino acids {(other amino acids C12P13/005)}
- Y10S 435/84: Brevibacterium
- Y10S 435/843: Corynebacterium
- C12P: FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE {(brewing of beer C12C; producing vinegar C12J; producing specific peptides or proteins C07K; producing enzymes C12N9/00; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; measuring or testing processes involving enzymes or microorganisms C12Q; measuring or testing processes involving nucleic acid amplification reactions C12Q1/6844; fermentation processes to form a food composition, A21 or A23; compounds in general, see the relevant compound class, e.g. C01, C07)}
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

Culturing an L-amino acid producing microorganism belonging to the genus Brevibacterium or Corynebacterium and having a resistance to a peptide containing glutamic acid or aspartic acid gives L-amino acids in high yield.

## Claims

### Claim 1

A process for producing an L-amino acid, which comprises culturing a mutant L-amino acid producing microorganism belonging to a genus selected from Brevibacterium and Corynebacterium which is resistant to a dipeptide at a concentration of 0.3% in a liquid medium for a time sufficient to produce said L-amino acid; and
recovering said L-amino acid produced wherein
1) L-glutamine is produced from a tyr-glu resistant mutant of Brevibacterium flavum ATCC 14067 or an ala-glu resistant mutant of Corynebacterium acetoacidophilum ATCC 13870;
2) L-lysine is produced from a val-glu resistant mutant of Brevibacterium lactofermentum ATCC 13869 or an ala-glu resistant mutant of Corynebacterium glutamicum ATCC 13032;
3) L-arginine is produced from a tyr-glu resistant mutant of Brevibacterium flavum ATCC 14067;
4) L-glutamic acid is produced from a tyr-glu resistant mutant of Brevibacterium lactofermentum ATCC 13869 or an ala-glu resistant mutant of Corynebacterium glutamicum ATCC 13032;
5) L-histidine is produced from a trp-glu resistant mutant of Brevibacterium flavum ATCC 14067 or a glu-his resistant mutant of Corynebacterium glutamicum ATCC 13032;
6) L-proline is produced by a tyr-glu resistant mutant of Brevibacterium flavum ATCC 14067; and
7) L-isoleucine is produced from an ala-asp resistant mutant of Brevibacterium flavum ATCC 14067, and
wherein said mutant microorganism is obtained by mutation of a parent strain, and said microorganism produces the L-amino acid in an amount greater than the amount produced by the parent strain.

### Claim 2 (depends on 1)

The process of claim 1, wherein said L-amino acid producing microorganism is obtained by contacting the parent strain with N-methyl-N'-nitro-N-nitrosoguanidine.

### Claim 3

A process for producing an L-amino acid, which comprises culturing a mutant L-amino acid producing microorganism belonging to the genus Brevibacterium which is resistant to a dipeptide at a concentration of 0.3% in a liquid medium for a time sufficient to produce said L-amino acid; and
recovering said L-amino acid produced, wherein the amino acid is L-glutamine, the mutant microorganism is a tyr-glu resistant mutant of Brevibacterium flavum ATCC 14067, the mutant microorganism is obtained by mutation of a parent strain, and the mutant microorganism produces the L-amino acid in an amount greater than the amount produced by the parent strain.

### Claim 4 (depends on 3)

The process of claim 3, wherein said L-amino acid producing microorganism is obtained by contacting the parent strain with N-methyl-N'-nitro-N-nitrosoguanidine.