Method for improving 2-keto-L-gluconic acid fermentation efficiency

Abstract

The invention relates to a method for improving 2-keto-L-gluconic acid fermentation efficiency. The method is characterized in that in the process of mixed strains fermenting 2-keto-L-gluconic acid, the mixed strains comprise ketogulonigenium vulgare and bacillus megaterium, seed solution cultured to the middle and later periods of logarithmic growth is inoculated into fermentation tank optimum culture media to ferment and culture, sorbose is fed since fermentation time is 0h, and small material culture media are fed at the prior period of the logarithmic growth. According to the method, production intensity of the 2-keto-L-gluconic acid can be improved, efficiency is improved, production capacity is optimized, the content of the 2-keto-L-gluconic acid in fermentation solution can reach 115.6-150.3mg / ml, acid producing rate is 2.89-3.76g.(L.h)-1, and the conversion rate of glucose acid is 87.2-95.0%.

Description

technical field

[0001] The invention belongs to the technical field of microbial fermentation, and in particular relates to a method for improving the production efficiency of 2-keto-L-gulonic acid fermentation, which is biased towards improving the vitamin C two-step fermentation process. Background technique

[0002] Vitamin C two-step mixed bacteria fermentation system, including two fermentation steps, is called two-step fermentation method: the first step is to oxidize D-sorbitol into L-sorbose under the action of black acetic acid bacteria, commonly known as alcohol sugar conversion; The first-step fermentation process is mature and the conversion rate is high, which can reach more than 98%. At present, the research on its related genes and transformation substrates at home and abroad has been relatively clear; the second step is to further oxidize L-sorbose into 2-keto- L-gulonic acid, commonly known as sugar-acid conversion; the second step is the mixed fermentation ...