JPS60248195A - Preparation of l-glutamine by fermentation - Google Patents

Abstract

PURPOSE:To obtain the titled substance, economically, by adsorbing various sucrose-containing liquid produced in the beet sugar production process to an ion exchange resin, eluting the adsorbed component, and adding the component to an L-glutamine fermentation medium, thereby effectively utilizing the waste liquid discharged from the desalting process of an ion exchange resin. CONSTITUTION:Beet juice or a sucrose-containing liquid produced in the process for producing refined sugar from beet juice, is made to contact with an ion exchange resin (e.g. strongly acidic cation exchange resin, strongly basic anion exchange resin, etc.), and the component adsorbed to the resin is eluted by a resin-regeneration technique to obtain a desalted waste liquid. The liquid is added to a medium for L-glutamine fermentation in an amount of >=100mg/l in terms of total nitrogen, and the mixture is sterilized, inoculated with a coryneform glutamine-producing strain [e.g. Brevibacterium flavum (FERM P-4272)], and cultured to obtain the objective substance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) L-glutamine is used as a drug for treating gastrointestinal ulcers, a drug for treating alcoholism, a drug for improving brain function, and the like. The present invention improves the method for producing L-glutamine by fermentation.

(Prior art) L-f rutamine is an amino acid that is mass-produced.
Various improvements have been made to the manufacturing method.

It is known that a substance that improves the fermentation yield of M can be obtained by extracting heat molasses with an organic solvent (Japanese Patent Publication No. 56-12111). It is not known that a substance that improves the fermentation yield of shim-glutamine is adsorbed by contacting it.

(Problems to be Solved by the Invention) Improving the fermentation yield is an important problem in order to reduce the production cost of L-glutamine.

[Structure of the invention]

The present invention was made in order to achieve such an object, and L-glutamine is added to an eluent obtained by contacting an L-glutamine fermentation medium with an ion exchange resin and various sucrose-containing liquids used in the beet sugar manufacturing process. This is based on the discovery that it contains a substance that improves fermentation yield.

(Means for Solving the Problems) The present invention involves bringing the sucrose-containing liquid in the process of producing beet juice or refined sugar from it into contact with an ion exchange resin, and eluting the components adsorbed on the ion exchange resin. , relates to a method for producing L-glutamine by a fermentation method, which is characterized by adding this to a medium used for L-glutamine fermentation.

In the process of manufacturing beet juice or refined sugar from it, the sucrose-containing liquid is the raw sugar juice obtained by squeezing beets, the liquid obtained by subjecting it to various purification methods such as decolorization, and the liquid obtained by separating sucrose crystals from it in several stages. These include mother liquor, beet molasses, and blackstrap molasses.

The ion exchange resin with which the beet juice or nokrose-containing liquid is brought into contact may be any ordinary one, such as a strongly acidic cation exchange resin,
There are various types of resins, such as medium to weakly acidic cation exchange resins, strongly basic anion exchange resins, and medium to weakly basic anion exchange resins, and any of them may be used.

The active ingredient used in the method of the present invention can be obtained by contacting beet juice or a solution containing noucrose with an ion exchange resin to elute the adsorbed components. Since desalination is carried out using an exchange resin, it is convenient to use desalination waste liquid from this ion exchange resin. This desalting process involves passing the cooled crude juice through a tower made of H-type strongly acidic cation exchange resin to exchange cations with hydrogen ions, and converting the strongly acidic sugar juice flowing out from the tower into OH-type weakly basic anions. This is carried out by passing an exchange resin through a tower to exchange anions with OH ions. During the regeneration of these ion exchange resins, various adsorbed components are eluted, and a large amount of this eluate is produced as a so-called ion exchange resin desalting waste liquid. This desalted waste liquid mainly contains inorganic salts, but also contains small amounts of organic acids, amino acids, and other organic nitrogen, and almost no sugar. The desalination waste liquid includes waste liquid from a cation exchange resin tower, a waste liquid from an anion exchange resin tower, and a mixture of the two, and any of them can be used in the method of the present invention. These may be added to the medium as they are, but it is generally more convenient to concentrate them to an appropriate concentration before adding them. The amount added to the culture medium can be set based on the total amount of nitrogen, usually 100 m9/l!
If the above amount is added, the effect of improving the yield can be obtained.

Other medium components may be the same as the usual medium used for L-glutamine fermentation, including glucose, nitrogen sources such as fumonium salts, ammonia, and urea, salts such as phosphates, magnesium salts, iron salts, and manganese salts, and biotin. , pikmin such as thiamine, organic micronutrients such as amino acids, etc. are used.

The microorganisms used in the method of the present invention may be ordinary L-glutamine producing bacteria, such as the so-called coryneform Brevibacterium flavum FERM-P4272.
Corynebacterium acetoacidophyllum ATCC1
3870 etc. are used.

The culture method and the method for collecting L-glutamine from the fermentation liquid may be carried out according to conventional methods, and no special method is required.

[Action and effect of invention]

The method of the present invention can improve the fermentation yield of L-glutamine by simply adding an ion-exchange resin-adsorbed component of the sucrose-containing liquid to the culture medium in the process of producing beet juice or refined sugar from it. This adsorbed component includes
Example: Since the ion-exchange resin desalination waste liquid, which is produced as a by-product in the process of producing refined sugar and has little utility value, can be effectively used, the burden of its disposal can be reduced, and L-glutamine can be economically advantageously produced.

〔Example〕

An ion exchange resin desalting waste liquid produced in the molasses desalting process at a beet sugar factory in Hokkaido was concentrated to a total nitrogen concentration of about 20 g/l.

Glucose 100P/d KH2PO42" MgSO4・7H200,5II (NH4)2SO415p Na2SO4151 FeSO44H201m9/13 Biotin thiamine hydrochloride at 4 μM 200 Soybean protein hydrolyzate 0.2y7/l (as total nitrogen concentration) 1 liter of medium with the above composition Place in a jar fermentor, adjust the pH to 7.0 with caustic soda, and incubate at 120℃ for 10 minutes.
Heat sterilized for minutes.・Add 1 part of the desalination waste liquid concentrate to this.
After heat sterilization at 20° C. for 10 minutes, the amount described above was added, and 50 ml of a seed culture of Brevibacterium flavum FERM-P 4272, which had been cultured in advance, was inoculated. The culture temperature was set to 31℃, and the pH was adjusted with ammonia gas.
Remaining course while keeping it at 5.5.

Aeration and stirring were continued until there was no more residue.

The concentration of glutamine in the obtained culture solution was measured by a conventional method to determine the yield relative to sugar. The results obtained are shown below.

Desalination waste liquid addition amount L-glutamine yield (Total nitrogen, rv/l) (%) 0 38] 100 38.6 500 39.0 1000 39.7 2000 4.1.8 5000 42.5

Claims (1)

[Claims] A method of contacting beet juice or a liquid containing sucrose in the process of producing refined sugar from it with an ion exchange resin, eluating the components adsorbed to the ion exchange resin, and adding this to the medium used for L-glutamine fermentation. Characterized by
Method for producing L-glutamine by fermentation method