JPS5914795A - Ultrafiltration process - Google Patents

Abstract

PURPOSE:To coagulate polymeric impurities in an amino acid fermentation liquid or in an intermediate liquid obtained before the separation of amino acid from the fermentation liquid, and to improve the rejecting ratio of the impurities, by adjusting the pH of the liquid to a specific level before ultrafiltration. CONSTITUTION:In the ultrafiltration and removal of polymeric impurities from an amino acid fermentation liquid or from an intermediate liquid obtained before the separation of the amino acid from the fermentation liquid and containing polymer impurities such as proteins, humus, polysaccharides, pigments, etc., e.g. a fermentation liquid or an intermediate liquid prepared from cane molasses, the ultrafiltration is carried out by adjusting the pH of the amino acid fermentation liquid or the intermediate liquid to 2-5 excluding the isoelectric point of the objective amino acid and thereabout.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to the prevention of ultra-high molecular weight impurities such as humic substances and polysaccharides contained in the amino acid fermentation liquid or the intermediate treatment liquid from which the target amino acid is divided and obtained. This will improve the rate. More specifically, in systems that contain a large amount of high molecular weight impurities, such as fermentation liquids made from cane molasses or their intermediately processed liquids, impurities such as pigments, humic substances, gum substances, polysaccharides, proteins, etc. There are many types1
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Among these, humic substances and some polysaccharides are so-called acidic substances that have carboxyl groups as functional groups, and in a certain acidic region they become uncharged, lose affinity with water, and precipitate. The purpose of the present invention is to take advantage of this property and adjust the pH of the intermediate treatment solution to a constant 9 acidic range, thereby coagulating and precipitating these polymeric substances and producing ultraviolet rays. This is to compare the rejection rate in the filtration process.

Here, the certain acidic region is pH 2 to 5. This region is suitable because it is at or near the isoelectric point of pigments, humic substances, etc. However, if the target amino acid has an isoelectric point within this region, it is natural to exclude the isoelectric point and the region near the warp. The pH can be adjusted using an acid or an alkali, and the acids that can be used include hydrochloric acid,
There are so-called mineral acids such as sulfuric acid, nitric acid, and phosphoric acid, and organic acids such as acetic acid.On the other hand, examples of alkalis include hydric soda, hydric potassium, lime, and ammonia.

Next, the actual operation of the present invention will be explained.

The target liquid to be treated according to the present invention V is an amino acid fermentation liquid using cane molasses as a carbon source or an intermediate treatment liquid thereof as described above, but before subjecting this liquid to ultrafiltration treatment. Then, adjust the pH to 2 to 5 (excluding the isoelectric point of the target amino acid and its vicinity) as described above.

The pH of the solution is adjusted in this way and the solution is subjected to ultrafiltration, but the ultrafiltration itself may be performed by a conventionally known method. For example, the material of the membrane used in ultrafiltration may be a normal semipermeable membrane, and there are no particular restrictions. For example, polyamide, polyacrylonitrile, exclusive rose acetate, etc. can be considered. The type of membrane may be a tube type, a flat membrane, a spiral membrane, a hollow fiber membrane, etc., and there are no particular limitations. There is no particular limit to the amount of molecular fraction t. There are no special conditions such as temperature.

The effects of the present invention will be shown below in Example t. In addition, in □ Example 1, the dye selection rate is the absorbance at 400 nm, and the polymer removal rate is the L value using the reducing property of humic substances.
It was measured by the owly Folin method.

Example 1 Glutamic acid fermentation liquid (pH
7,2) was adjusted to I)H4,13 with hydrochloric acid, and subjected to ultrafiltration treatment at 40C using a polyacrylic hollow fiber ultrafiltration membrane (molecular fraction 13.000).
A comparison was made with the case where 2') was subjected to ultrafiltration treatment as it was.

The results are shown in Table 1.

Table 1 From the above table, by adjusting the pH to a specified value, the removal rate of polymer reducing substances is 50%, and the selection rate of pigments is 50%.
It is understood that the increase has been %. Such an increase naturally also improves the purity of the fermented noic acid crystals.

Example 2 Lysine fermentation liquid (pH 7.0) using gain molasses as raw material
) itself (engraved) and the one with pH adjusted by 4t (
(the present invention), ultrafiltration was carried out in the same way as before.

The results are shown in Table 2t. From this table, it can be seen that when Invention 1 was applied, the removal rate of the polymeric reducing substance increased by 36%, and the selection rate of the dye increased by 60%.

Table 2 Patent Applicant Ajinomoto Co., Ltd. Procedural Sodochunran] 111 Wa ffl 8 I 11 () Month 11, Indication of the case ・ flil Japanese Patent Application No. 125529 No. 125529 of 1957, Filtration method excluding the title of the invention 3. Relationship with the case of the person making the amendment Patent I'1 Applicant A 1 Tokyo Chuubi 1g Kyobashi-chome 5-8 □ 6. Subject of the amendment Claims column 7 of the specification.
Contents of Supplementary iIE (1) Clarification 111i; The scope of the claims in J is amended and covered as shown in the attached sheet.

(2) "Polysaccharide" described in page 1, line 14, line 1 of the specification has been corrected to "pigment." The statement on page 2, line 3 of the specification is corrected as "Polysaccharide 1". 1 pigment 1 is 1 part of the pigment described in line 13 of the second chapter of the detailed description, ii ■ jl', j
I will.

Attachment 2, Claims Humin T1, Win7in 1, which contains a large amount of polymeric substances such as pigments! , the amino acid photointoxicating solution with λ as the raw material for fermentation, or the intermediate treatment solution used to separate the target product, is subjected to ultrafiltration treatment to remove the polymeric substances. The ultrafiltration method 3゜ is characterized by adjusting the liquid level 1) to 2~5 in advance.

Claims (1)

[Claims] The amino acid fermentation liquid made from gain molasses containing many polymeric impurities such as proteins, humic substances, and polysaccharides is used as a fermentation raw material, or the intermediate treatment liquid used to separate and obtain the target product from this is subjected to one ultrafiltration process. An ultrafiltration method characterized by adjusting the pH of the liquid in advance from 2 to 51 before removing the polymeric substance.