Method using three-bacterium mixed fermentation to convert sorbose into 2-keto-L-gulonic acid

Abstract

The invention belongs to the technical field of vitamin C biological fermentation, and particularly relates to a method using three-bacterium mixed fermentation to convert sorbose into 2-keto-L-gulonic acid which is in a second step of the vitamin C biological fermentation. Seed solution of manufacturing technique of the second step of the vitamin C biological fermentation is enlarged step by step, when in fermental cultivation, with total inoculation amount with volume percent of 15-20%, seed solution of A isolates and B isolates are introduced into a fermentation tank to be fermented and cultivated to a fermentation ending point (namely when the concentration of remained sorbose in fermentation liquor is smaller than or equal to 1mg / ml), and the purpose that the mixed bacteria fermentation is adopted for converting the sorbose to the 2-keto-L-gulonic is achieved. The A isolates is composed of companion fungus bacillus cereus / companion fungus bacillus megatherium and acid-forming bacteria ketogenic base ketogulonigenium vulgare. The B isolates is composed of companion fungus bacillus thuringiensis and acid-forming bacteria ketogenic base ketogulonigenium vulgare. According to the novel method using the three-bacterium mixed fermentation, respective advantages of the two kinds of the companion funguses are made full use, fermentation period can be shortened by 6-8 hours, energy consumption is reduced by 10-15%, and fermentation conversion percent is improved by 2-4%.

Description

technical field [0001] The invention belongs to the technical field of vitamin C biofermentation, and specifically relates to a method for transforming sorbose 2-keto-L-gulonic acid by using mixed bacteria in the second-step biofermentation of vitamin C. Background technique [0002] The industrial production of Vc two-step fermentation, the second step fermentation is the mixed fermentation of two kinds of bacteria to realize the biotransformation from L-sorbose to 2-keto-L-gulonic acid. The two types of bacteria include bacteria with acid production ability - common ketogenic cologne (commonly known as acid-producing bacteria or small bacteria) and associated bacteria that do not have the ability to transform acid production but can promote the growth and acid production of small bacteria (commonly known as large bacteria). Existing research results have shown that common keto-L-gulonic acid bacteria have weak subculture survival rate and 2-keto-L-gulonic acid production ...

AI Technical Summary

Problems solved by technology

Because the high-efficiency associated ability of an associated bacterium lasts for a short period of time, it is difficult to continuously provide sufficient effectors throughout the fermentation stage. Therefore, the acid-producing ability of acid-producing bacteria cannot be maintained at the best state for a long time during the fermentation process, making the second It is difficult to effectively improve the efficiency of two-step mixed bacteria fermentation

In addition, due to the lag of the test results and the complexity of the multi-stage expansion process of the seed liquid, the large tanks of the two-step mixed-bacteria fermentation often appear to be contaminated with bacteria and phages, and the phages kill the associated bacteria, making the associated factors unable to meet the growth of acid-producing bacteria. and fermented acid, resulting in a significant reduction in fermentation speed and even the occurrence of tanks, which seriously affected the production of gulonic acid and caused a large amount of energy consumption and material loss

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