JPS60137296A - Production of l-lysine - Google Patents

Abstract

PURPOSE:Molasses is treated with a cationic ion-exchange resin and subjected to fermentation to achieve high-yield production of L-lysine through fermentation process. CONSTITUTION:Cane molasses or beet molasses is diluted into an appropriate concentration of saccharides, e.g., 10-55g/dl, then passed through a cationic ion-exchange resin, and eluted with water. The resultant eluate is used as a carbon source to produce L-lysine by a known fermentation process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing L-lysine (hereinafter abbreviated as lysine) from molasses.

Molasses is a by-product produced in the sugar manufacturing industry, such as sucrose or beet sugar. Molasses is a sugar solution that mainly contains sucrose, but it also contains a large amount of impurities in addition to sugar. cannot be separated economically, and is currently used as a raw material for L-glutamic acid fermentation, lysine fermentation, or alcohol fermentation.

However, even when used as a fermentation raw material, there are a large amount of impurities, especially salts and colored substances, so it is difficult to separate and purify the fermented product and to treat waste liquid. This poses a large cost burden. Lysine fermentation liquid is usually separated and purified by a process in which lysine is adsorbed to a cation exchange resin under acidic conditions, but a large amount of contaminant cations such as potassium and calcium derived from molasses are present in the fermentation liquid. Therefore, the resin must be treated under strong acidity. That is, as is well known, basic amino acids such as lysine can absorb Pll, monovalent cations and divalent cations, and divalent ions have a stronger adsorption ability to ion exchange resins than monovalent ions. Therefore, if there are few contaminant cations, it is sufficient to adsorb them with a monovalent ion of pH 4.5, but if there are many contaminant cations, such as in the lysine fermentation liquid used as raw material for molasses, remove the contaminant cations. In order to adsorb P, which is a divalent ion, it must be adsorbed at around 2.

'For this reason, the amount of acid used for adsorption, the amount of alkali used for elution, and the amount of alkali used to neutralize the adsorption waste liquid are all large, which has the disadvantage of a large cost burden. Ta.

Therefore, the present inventors conducted various researches to develop a method to inexpensively separate and purify the fermentation liquid using molasses as a raw material. When water is poured into the resin column and an eluate section containing sugar is collected, various cations contained in the molasses are replaced with one type of cation or removed in the sugar eluate section. If the sugar eluate fraction is used as a carbon source for producing lysine by fermentation, the amount of acid and alkali used when separating and purifying lysine in the lysine fermentation solution using a cation exchange resin can be reduced. They have discovered that it is possible to significantly reduce the amount of heat generated, and have completed the present invention.

That is, in the present invention, molasses is passed through a tower packed with a cation-type cation exchange resin, water is poured into the resin tower, and the eluate fraction containing sugar is used as a carbon source for producing L-IJ lysine by a fermentation method. The present invention relates to a method for producing L-lysine.

The molasses used in the present invention is molasses such as cane molasses and beet molasses.

The cation exchange resin used in the present invention is r - r
Nharite IR-120J, “Dowex-50”
There are strong acidic cation exchange resins such as ``Diaion S-IB'' and weakly acidic cation exchange resins such as ``Amberlite IRC-50J, r Amberlite XE-80J'' and ``Diaion WK-114.'' teeth,
Use in H type or NH4 type. In the case of the NH4 type, N)I3 transferred to the treated molasses is effectively used as a fermentation medium. In the case of HW, the voice of the treated molasses decreases, but it can be used after neutralizing it with NH3.

In the present invention, after passing molasses through a tower packed with a cation-type cation exchange resin, water is poured through the resin tower to collect the eluted fraction containing sugar. After filling a resin column and supplying diluted molasses with an appropriate sugar concentration, for example 10 to 55 E/dt, to this packed column, water is allowed to flow through the resin column and the ion-substituted molasses flowing out is recovered. good. The operating temperature is from room temperature to 90°C, preferably from 50 to 80°C, and the feed rate is from 0.5 to 58V (elution volume/resin volume in X hours). The ion exchange capacity of the ion exchanger has been exceeded and other cations have been mixed into the flowing molasses at an ion equivalent ratio of 1 to 7.
%, the supply of molasses will be discontinued. The ion exchanger can be used any number of times if it is regenerated, and the regeneration method can be any conventional method, and any regenerating agent may be used.

In addition, prior to the ion exchange resin treatment, solids contained in the molasses, so-called sludge, are removed using an ultrahigh-speed centrifugal separator, such as Westphalia's 5AOH model, and phosphoric acid or phosphates are added to make the molasses cloudy. By removing calcium salts as well as carbon, the load on the ion exchanger during ion exchange resin treatment can be reduced.

By subjecting the ion-substituted molasses using the above method to normal lysine fermentation, the fermentation yield is dramatically improved compared to when untreated molasses is used.

The sugar obtained in this way is used as a carbon source by fermentation method.
jl In order to produce IJ lysine, the culture conditions of organisms conventionally used are not particularly sophisticated.

Examples of conventionally known microorganisms capable of producing lysine include the following.

Brevibacterium? flavum ATCC21475゜Brevibacterium, 7-Rakudofamen'tumATC
C21798, Brevibacterium 2#-shift fermentum FERMP-1944, Corynebacterium)
Glutamicum FEBMP-1986 The carbon source contained in the medium is the sugar obtained by the method of the present invention, but small amounts of other carbon sources such as raw sugar, starch acid, or enzyme melted products may also be used in combination. Good: The obtained round fermented liquid may be left with bacterial cells, or the bacterial cells may be removed by an appropriate method, and then - adjusted to 2 to 5 with mineral acid.

Thereafter, a purified lysine solution can be obtained by adsorbing it onto a cation exchange resin and eluting it with a suitable eluent.

The adjustment to be made prior to adsorption may be determined by the degree of decationization of the molasses. That is, when most of the cations are removed, the pH may be around 4 to 5, where lysine is a monovalent cation, and as the cation removal rate decreases, lysine becomes a divalent cation (P) (2
It would be better if we could get closer to it.

As described above, depending on the degree of decationization of molasses, it is possible to reduce the amount of mineral acid that should be used during resin treatment of fermentation liquor.

Examples will be described below.

Example Water is added to beet molasses or cane molasses to adjust the sugar concentration to about 50,117 dt. NH4 type cation exchange resin (Diaion 5K-IBJ) 240d
The jacket temperature of the ram (30φ x 300m! 11) filled with molasses was maintained at 50℃, and the molasses with adjusted concentration was
The temperature was adjusted to 0° C., the molasses was supplied at SV2 (480 mJ?/Hr), and the molasses flowing out from the packed column was collected for 500 days. Molasses treated with ion exchange resin was analyzed by atomic absorption and high performance liquid chromatography to determine Na and K.

Analysis of Mg, Cm, and NH3 revealed that 97% of the ion equivalent of beet molasses and 98% of the ion equivalent of cane molasses were replaced by NH4.

After the ion exchange resin treatment, the resulting treated molasses was adjusted to a sugar concentration (sucrose equivalent) of 45%, and
001m was mixed with 200+d of a salt solution having the composition shown in Table 1 to prepare a medium for fermentation of 300-lysine.

Table 1 Composition of salt solution KH2P O40,1517dt MgSO,・7I(,OO,06# Fe3O4”IH201,5m97atMnSO<・
4) ItO' 1.5 1thiamine hydrochloride 30 μ
m77dt soybean protein hydrolyzate (TN 6.9/dA)
3. Pour 300 d of the lysine production medium prepared in this way into a 1.0 I capacity fermenter, and
Heat sterilization was performed at 15° C. for 10 minutes. This was pre-cultured with Prehyacterium lactofermentum FERM-
P-1944 was inoculated and cultured at 31.5°C for 2 days with aeration and agitation while maintaining the temperature at 6.5 with ammonia gas. It is shown in Table 2.

Table 2 Lysine Fermentation Yield L-Lysine (in terms of hydrochloride) /-Dark Punishment---Kan-A---Yu---h. 10111 The obtained fermentation liquid was adjusted to P2 and 4 with sulfuric acid, respectively, and cation exchange resin (
The saturated adsorption amount of lysine on "Diaion 5K-IBJ" was measured. The results are shown in Table 3.

Table 3: Saturation adsorption amount of lysine (77/l Re5in)
Note that the same beet molasses or cane molasses as in this example was fermented under the same conditions without cation exchange resin treatment, and the fermented liquid was fermented with cation exchange resin ("Diaion 8 K-I BJ") under sulfuric acidity. ) The saturated adsorption amount of lysine is shown in Table 3.

Applicant: Ajinomoto Co., Inc.

Claims (1)

[Claims] After passing the molasses through a column packed with a cation-type cation exchange resin, water is flowed through the resin column, and the eluate fraction containing sugar is used as a carbon source for producing L-lysine by a fermentation method. A method for producing L-lysine, characterized by: