KR19980039740A - Corynebacterium glutamicum CH25, an L-leucine producing microorganism - Google Patents

Abstract

The present invention is a novel L-leucine producing microorganism, in particular Corynebacterium glutamicum CH25 (Corynebacterium glutamicum; accession number) characterized by resistance to norleucine, α-aminobutyric acid and L-arginine hydroxamate. KFCC-10931) and a method for producing L-leucine characterized by culturing this microorganism to accumulate L-leucine in a medium.

Description

Corynebacterium glutamicum CH25, an L-leucine producing microorganism

The present invention is a novel L-leucine producing microorganism, in particular Corynebacterium glutamicum CH25 (Corynebacterium glutamicum; accession number) characterized by resistance to norleucine, α-aminobutyric acid and L-arginine hydroxamate. KFCC-10931) and a method for producing L-leucine characterized by culturing this microorganism to accumulate L-leucine in a medium.

L-Leucine is a kind of essential amino acid, widely used in medicines, foods, feed additives, and industrial medicines. It is mainly manufactured and commercialized by direct fermentation methods by companies such as Ajinomodo and Co. Fermentation.

Conventional methods for producing L-leucine include methods using L-valine demanding mutant strains (Japanese Patent Laid-Open No. 38-4395); methods using α-aminobutyric acid resistant strains (see Japanese Patent Publication No. 47-26313, J. of Biochem. 73. 105, 1973); Method of using s- (2-aminoethyl) -L-cysteine resistant mutant (see Japanese Patent Application Laid-Open No. 51-37347); Method of using a norleucine resistant mutant that is an analog of leucine (see Japanese Patent Publication) 56-1912); Method of producing L-leucine by coryneform bacteria resistant to valine analogs (Japanese Patent Laid-Open No. 63-248392), method of producing L-amino acid by fermentation (Japanese Patent Laid-Open No. 6-133788), A method for producing L-leucine by Corynebacterium microorganisms requiring L-isoleucine and L-histidine at the same time (Korean Patent Publication No. 93-21793), etc. Acid microorganism, Corynebacterium glutami It relates to Corynebacterium glutamicum CH25. _{4 2 4 2 4 2 4 4 2 4 2 4 2}

Meanwhile, Table 2 below shows the results obtained by observing the growth of the ATCC 13032 strain against α-aminobutyric acid, which is a simultaneous analogue of L-isoleucine and L-valine, in the same manner as in Table 1. . As can be seen from Table 2, the ATCC 13032 strain did not grow at all in α-aminobutyric acid at a concentration of 10 g / L.

Accordingly, the present inventors have determined that against the known strain Corynebacterium glutamicum ATCC 13032 for norleucine, α-aminobutyric acid and L-arginine hydroxamate, as described in the Examples below, based on the above experimental results. By inducing resistance, the desired microorganism according to the present invention was obtained.

Corynebacterium glue grown in Luria bertani (LB) liquid medium to the middle of the logarithmic phase ^{7 8} _{4 2 4 2 4 4 2 4 2 4 2 2} Strain fermentation was significantly improved.

Example 2

In order to investigate the effect of amino acid addition on the production of L- leucine of strain CH15 obtained in Example 1, each of the amino acids shown in Table 4 was added to the flask titer by fermentation by adding 1.0 g / l to L-arginine only. It has been found to be an effective amino acid for L-leucine production.

Table 4. Effect of Amino Acids on L-Leucine Fermentation of CH15

However, rather than artificially adding L-arginine to improve L-leucine fermentation concentration, it would be desirable to give L-arginine direct production within cells by conferring resistance to L-arginine analogs to the bacteria themselves. In view of the present invention, in the present invention, it was decided to confer L-arginine hydroxamate resistance to strain CH15 obtained in Example 1, and first confirmed the resistance of the CH15 strain to L-arginine hydroxamate. Cell growth did not occur (see Table 5).

Table 5. Effect of L-Arginine Hydroxamate on Growth of CH15 Strains

Example 3

Sterile CH15 strains grown in Luria bertani (LB) liquid medium to mid- logarithmic season

Therefore, the novel strain obtained according to the present invention is named as Corynebacterium glutamicum CH25 so that L-leucine can be accumulated in a large amount in the medium, and deposited on the KFCC on November 19, 1996 with the Korean spawn association. You have been assigned a deposit number of -10931.

Claims (4)

Resistance to norleucine, α-aminobutyric acid and L-arginine hydroxamate The microorganism of claim 1, wherein the microorganism is resistant to L-arginine hydroxamate at a concentration of 5 g / l. The microorganism according to claim 1 or 2, which is Corynebacterium glutamicum CH25 (Accession No .: KFCC-10931). L-Louis in the medium by culturing the microorganism according to any one of claims 1 to 3.