Genetic engineering strain capable of high yielding L-cysteine and construction and application of genetic engineering strain

Abstract

The invention relates to a genetic engineering strain capable of high yielding L-cysteine, a construction method for the genetic engineering strain and application of the genetic engineering strain in microbial-fermentation preparation of the L-cysteine. According to the method, the Escherichia coli genetic engineering strain capable of high yielding the L-cysteine is obtained through (1) strengthening the efficiency of conversion of the L-cysteine from S-Sulfocysteine in an Escherichia coli L-cysteine synthesis way and (2) strengthening the utilization ratio of thiosulfate radicals in the Escherichia coli L-cysteine synthesis way, and the yield of the L-cysteine is increased to 4.88g / L from 3.90g / L.

Description

[0001] (1) Technical field

[0002] The present invention relates to a genetic engineering of high-yield L-cysteine ​​and a construction method thereof, as well as its application of L-cysteine ​​in microbial fermentation.

[0003] (2) Background

[0004] Cysteine ​​(Cysteine, Symbol Cys or C) has two homomers: L-cysteine ​​and D-cysteine. Most of the biological body is L-cysteine, which is one of the main presence forms of S element in the organism, which is a metabolic source of a large sulfur-containing compound. L-cysteine ​​is a semi-essential amino acid having a molecular formula HSCH2CH (NH2) COOH, which is usually involved in certain enzymatic reactions as a nucleophilic reactor due to a mercapto-side chain. L-cysteine ​​sulfhydryl can easily oxidize cystine, and they play an important role in maintaining protein structures. In addition, L-cysteine ​​also has a variety of physiological effects in biosurbs, such as anti-oxidation, participating antibiotics. Tolerance, also has important r...

Images