Separation and purification method of L-valine

Abstract

The invention discloses a separation and purification method of L-valine. The method comprises the following steps: S1, filter-pressing, S2, micro-filtration membrane filtering; S3, concentrating andcrystallizing; S4, dissolving; S5, ion exchanging; S6, ultra-filtering and concentrating; and S7, crystallizing and drying. The separation and purification method comprises the advantages that the yield of the L-valine is improved, and the content of isoleucine in the L-valine is reduced, thereby providing technical support for the industrial development of the L-valine of our country.

Description

technical field [0001] The invention relates to the field of microbial fermentation, and relates to a method for separating and purifying L-valine. Background technique [0002] L-valine (L-val), scientific name 2-amino-3-methylbutyric acid, is one of the eight essential amino acids for the human body. It is collectively called branched-chain amino acids together with L-leucine and L-isoleucine. It is widely used in medicine, seasoning, cosmetics, nutritional additives, feed additives, etc. [0003] The production methods of L-valine mainly include extraction method, synthesis method and fermentation method. Among them, microbial fermentation method has the advantages of low raw material cost, mild reaction conditions and easy realization of large-scale production, and has become a widely used production method. [0004] Separation and purification is an important process in the industrial production of L-valine. Usually, the cost of separation and purification accounts for...

AI Technical Summary

Problems solved by technology

The precipitation method is based on the specific combination of the precipitant and L-valine to form a precipitate, and then separate and extract. This method has the advantages of high yield and easy operation, but there is a technical problem of high environmental pollution; less, but the membrane filtration method can only remove a large amount of inorganic salt ions and macromolecular impurities, and the amino acids similar to L-valine in the fermentation broth cannot be eradicated, and the obtained L-valine has high impurities; The ion exchange method is to adjust the pH of the fermented liquid from which the bacteria have been removed to be acidic, use a strong acidic cation exchange resin to separate L-valine and impurity amino acids, and finally separate L-valine by elution with ammonia water

If the purity of L-valine is improved, it is necessary to adopt multi-stage ion exchange columns for serial extraction, which will lead to a large amount of production wastewater in the production process, and the extraction yield by ion exchange method is also low

[0005] CN105274182A discloses a process for efficiently extracting L-valine from fermentation broth, comprising the following steps: 1) fermentation, 2) microfiltration membrane filtration: 3) evaporation concentration, 4) crystallization, 5) dissolution, 6) ionization Exchange, 7) ultrafiltration membrane filtration, 8) vacuum concentration and 9) centrifugal drying, this invention adopts the combined use of membrane filtration method and ion exchange method, which improves the extraction yield and purity of L-valine, but this invention does not The crystallization effect was not paid attention to, resulting in an unsatisfactory yield of L-valine, only about 68%

Although the present invention can obtain L-valine with higher purity, because the solubility of valine in pure water does not change much with temperature, the present invention adopts cooling crystallization, and a large amount of solutes are still dissolved in the solvent when the crystallization is finished. In the process, the yield of crystallized product is low, which leads to the low actual yield of L-valine product, which cannot realize industrialization

[0007] At present, the separation and purification technology of L-valine in my country is backward, and a large amount of solutes are still dissolved in the solvent during the crystallization process, resulting in low yield of crystallized products, which greatly affects the output of L-valine. At the same time, the separation and purification process is complicated , the cost is high, resulting in the poor market competitiveness of my country's domestic L-valine, and it is impossible to achieve large-scale production