Method for improving fermentation production efficiency of 2-keto-L-gulonic acid

Abstract

The invention discloses a method for improving fermentation production efficiency of 2-keto-L-gulonic acid. The method comprises the following steps: inoculating a well cultured mixed bacterial liquid of ketogulonigenium vulgare and bacillus megaterium into a fermentation culture medium containing 2% of sorbitol, 1.1% of corn steep liquor, 0.2% of urea, 0.02% of magnesium sulfate and 0.05% of potassium dihydrogen phosphate, stirring the fermentation culture medium in a fermentation container at the rotational speed of 400rpm, enabling the ventilation ratio to be 1: 1, enabling the initial pH value of the culture medium to be 6.7, starting to perform flow feeding of a sorbitol solution with the concentration of 25% after 10h of the culture, and controlling the final total polysaccharide concentration of fermentation to be 10%; and regulating the pH value to 4.5-5.0 by using 50% of phosphoric acid solution, then continuously controlling the fermentation pH value to 6.7-7.3 by using 25% of sodium carbonate solution and adding casein tryptone. According to the method disclosed by the invention, the biological synthesis rate of the 2-KLG (2-keto-L-gulonic acid) by a mixed bacterial system is effectively improved, and the purpose of improving the fermentation production efficiency is achieved.

Description

technical field [0001] The invention relates to a method for improving production efficiency, in particular to a method for improving 2-keto-L-gulonic acid fermentation production efficiency. Background technique [0002] 2-Keto-L-gulonic acid (hereinafter referred to as 2-KLG) is an important intermediate for the synthesis of vitamin C. At present, major domestic vitamin C manufacturers adopt the "two-step fermentation" production process. The key step of this process is its The second step of fermentation process: L-sorbose is biologically oxidized to 2-KLG under the action of a mixed strain of Ketogulonigenium vulgare and Bacillus megaterium , where common ketogenic cologne produces 2-KLG, and Bacillus megaterium is an associated bacterium, which does not produce 2-KLG. Since the fermentation process adopts a mixed-bacteria fermentation mode, it is difficult to effectively control the mixed-bacteria ratio in the fermentation production process To achieve the ideal state,...

AI Technical Summary

Problems solved by technology

[0002] 2-Keto-L-gulonic acid (hereinafter referred to as 2-KLG) is an important intermediate for the synthesis of vitamin C. At present, major domestic vitamin C manufacturers adopt the "two-step fermentation" production process. The key step of this process is its The second step of fermentation process: L-sorbose is biologically oxidized to 2-KLG under the action of a mixed strain of Ketogulonigenium vulgare and Bacillus megaterium , where common ketogenic cologne produces 2-KLG, and Bacillus megaterium is an associated bacterium, which does not produce 2-KLG. Since the fermentation process adopts a mixed-bacteria fermentation mode, it is difficult to effectively control the mixed-bacteria ratio in the fermentation production process To achieve the ideal state, there are still technical bottlenecks such as long cycle time and high energy consumption that restrict production efficiency in actual production. Therefore, it is very important to improve the production efficiency of 2-KLG fermentation by improving the original fermentation production process to adjust the mixed bacteria ratio.