Gene mutation and strain breeding method of L-hydroxyproline acid yield improving strain

Abstract

The invention relates to a gene mutation and strain breeding method of an L-hydroxyproline acid yield improving strain. The method comprises the following steps of (1) YPS culture medium preparation:preparing a YPS culture medium from 5g of peptone and 2.5g of yeast extracts; M culture medium preparation: preparing a M culture medium from 5g of sodium chloride; performing uniform mixing; reachingthe constant volume of 0.5L; regulating the pH value to 7.0 to 7.1; adding different concentrations of sodium acetate into an agar culture medium; (2) seed culture: taking 25mu l of glycerol for strain preservation; inoculating the strains into a 5ml YPS culture medium contained in a 15ml test tube; performing water bath shake bed culture over the night at 37 DEG C and 200rpm / min; transferring 0.5ml of materials into a 250ml conical flask; performing reciprocating shaking bed culture for 4 hours at 33 DEG C and 200rpm / min; (3) batch culture: using a miniature glass reactor using magnetic stirring; (4) continuous culture: charging 250ml of liquid into the miniature glass reactor; performing inoculation at the quantity of 2.5ml; performing ventilation for 1.5vvm at 37 DEG C; controlling theflow rate of a culture medium going into or out of the miniature glass reactor by a peristaltic pump; performing sampling every four hours to determine residul sugar and pH; (5) mutagenesis; (6) completion: performing screening to obtain three mutant strains; performing culture for 24 hours at an MA culture medium containing 10g / l glucose and 10g / l sodium acetate.

Description

technical field [0001] The invention belongs to the field of biochemical production, and relates to a gene mutation and strain selection method for microbial fermentation, in particular to a gene mutation and strain selection method for improving L-hydroxyproline acid production. Background technique [0002] At present, the production of L-hydroxyproline by microbial fermentation is still in its infancy, especially the acid production of strains is low. The acid production of L-hydroxyproline industrially produced by the fermentation process of the existing technological strains is low (about 3-3.5% acid production), and the cycle is long (55-60 hours), resulting in high energy consumption and low yield. low downside. Contents of the invention [0003] The purpose of the present invention is to provide a method for improving the gene mutation and strain selection of L-hydroxyproline acid-producing bacteria, which greatly improves the fermentation acid production rate of ...

AI Technical Summary

Problems solved by technology

The acid production of L-hydroxyproline industrially produced by the fermentation process of the existing technological strains is low (about 3-3.5% acid production), and the cycle is long (55-60 hours), resulting in high energy consumption and low yield. low disadvantage