JPH099983A - Production of l-tryptophan - Google Patents

Abstract

PURPOSE: To produce L-tryptophan simply by culturing a specific microorganism with an L-broth culture medium containing a specified component without especially using a substrate. CONSTITUTION: A microorganism, belonging to the genus Enterobacter, Bacillus or Pseudomonas and having the ability to produce L-tryptophan is cultured in an L-broth containing a yeast extract and a trypton to produce and accumulate the L-tryptophan, which is then collected to produce the L-tryptophan.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing L-tryptophan. More specifically, it relates to a method for producing L-tryptophan by a microorganism.

[0002]

2. Description of the Related Art Various methods for producing L-tryptophan by microorganisms have heretofore been proposed, but most of these methods use serine and indole as substrates for L-tryptophan production (see, for example, (Kaisho 56-85291).

[0003]

An object of the present invention is to provide a method for producing L-tryptophan by simply culturing the microorganism itself without using a substrate for producing L-tryptophan. .

[0004]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
A medium containing yeast extract and tryptone, generally
In L-broth medium, a microorganism belonging to the genus Enterobacter, Bacillus or Pseudomonas having the ability to produce L-tryptophan is cultured to produce and accumulate L-tryptophan, which is collected to produce L-tryptophan. To be achieved.

The microorganisms used here are E. coli which is a microorganism belonging to the genus Enterobacter isolated from soil in Fujisawa City, Kanagawa Prefecture. agglomerans No.204-2 (FE
RM P-14809; Microorganism 1), a microorganism belonging to the genus Bacillus B. alcalophilus No.201-7 (FERM P-14808; microorganism 2) or a microorganism belonging to the genus Pseudomonas P. ci
chorii No.209-1 (FERM P-14810; microorganism 3) and the like are used.

These microorganisms consisted of L-broth (10 g tryptone, 5 g yeast extract, 2.5 to 5 g sodium chloride in distilled water 1
5 ml of pH 7.0-7.2 medium dissolved in L) was placed in a test tube, 1 g of soil was added thereto, and the mixture was shake-cultured at 37 ° C. for 24 hours for separation.

The microorganisms 1 to 3 have the following mycological properties. Microorganism 1 Microorganism 2 Microorganism 3 A. Morphology (1) Cell morphology Bacillus bacilli Bacillus (2) Cell size (μm) 1 × 1 to 2 0.5 × 1 to 2 0.5 × 2 to 3 (3) Motility Yes Yes (4) Spores No Yes Yes No (5) Gram stainability Negative Positive Negative B. Growth condition in medium L-broth agar plate medium Yellowish brown Yellowish brown Yellowish brown Smooth or smooth C. Physiological properties (1) Nitrate reduction ＋ － ＋ (2) VP test － － － (3) Indole formation － － － (4) Hydrogen sulfide formation － － － (5) Citric acid utilization － － － (6) Pigment formation − − − (7) Urease − − − (8) Oxidase + − − (9) Growth pH range 5 to 9.5 5 to 8 5 to 8.5 (10) Growth temperature range (° C) 25 to 45 30 to 40 30 to 45 (11) Attitude toward oxygen Aerobic Aerobic Aerobic (12) Acid production from sugars D-Glucose ＋＋＋ D-Mannit ＋＋＋＋ Adonite －－－ L-arabinose ＋ －－ Inosit ＋ －－ Rhamnose ＋ － − Sorbit − − − Maltose ＋ ＋ ＋ Sucrose ＋ ＋ ＋

[0008] Based on these mycological properties, each microorganism was identified as Bergey's Mannual of Determinative Bacteriology.
As a result of searching by the 9th edition, microorganism 1 is Enterobacter
Being agglomerans No.204-2, microorganism 2 is Baci
llusalcalophilus No.201-7, but microorganism 3 is P
It was confirmed that they were seudomonas cichorii No.209-1.

These microorganisms were inoculated into an L-broth medium containing yeast extract and tryptone, and cultured at a culture temperature of 37 to 40 ° C. for about 3 to 5 days.
Tryptophan is produced and accumulated. Separation of L-tryptophan from the culture solution is performed by a usual method. As the L-broth medium, one generally used for culturing microorganisms is used as it is.

[0010]

EFFECTS OF THE INVENTION Generally, in order to efficiently produce L-tryptophan by a microorganism, a substance serving as a substrate is required, but in the present invention, yeast extract and tryptone (cultivated using whey) were used. L-tryptophan can be produced only by culturing a specific microorganism using a medium containing the extract) without using a substrate.
In this method, it is assumed that tryptophan is produced by consuming the glucose-like substance contained in the yeast extract in the medium such as L-broth medium.

[0011]

Next, the present invention will be described by way of examples.

Examples 1 to 3 Microorganisms 1, 2 or 3 were inoculated in 10 ml of L-broth and cultured at a predetermined culture temperature for 3 to 5 days. The amount of L-tryptophan produced and accumulated in the culture medium was quantified by high performance liquid chromatography (HPLC) with respect to the culture medium, and the following results were obtained. Example Microbial culture temperature (° C) L-tryptophan production (μg / ml) 1 1 40 300-310 2 2 37 230-250 3 3 40 300-330

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Claims (3)

[Claims] 1. A method of culturing a microorganism belonging to the genus Enterobacter having the ability to produce L-tryptophan in a medium containing yeast extract and tryptone to produce and accumulate L-tryptophan, which is then collected. A method for producing L-tryptophan. 2. A method of culturing a microorganism belonging to the genus Bacillus having the ability to produce L-tryptophan in a medium containing yeast extract and tryptone to produce and accumulate L-tryptophan, which is characterized by being collected. L-
Method for producing tryptophan. 3. A method for producing and accumulating L-tryptophan by culturing a microorganism belonging to the genus Pseudomonas having the ability to produce L-tryptophan in a medium containing yeast extract and tryptone, which is collected. Method for producing L-tryptophan.