2-keto-l-gulonic acid high concentration fermentation production technology

Abstract

The invention discloses a production technique of 2-keto-L-gulonic acid by high concentration fermentation. In a fermentation medium adopted by the production technique, the initial sorbin concentration is 15mg / ml to 25mg / ml; fermentation is carried out for 4 hours to 8 hours; continuous sorbin feeding is started; fermentation is carried out for 36 hours to 44 hours and then sorbin feeding is finished; during the feeding process, the content of sorbin is controlled to be 15 mg / ml to 30 mg / ml; when fermentation is carried out for 24 hours to 40 hours, pH value is adjusted to be 7.1 to 7.3; when fermentation is carried out for 40 hours to 44 hours, pH value is adjusted to be 7.4 to 7.6 until fermentation is finished; and dissolved oxygen during the whole fermentation process is controlled to be 30 percent to 50 percent. The technique adopted by the invention has total fed sorbin with a concentration of 10.5 percent to 11.5 percent (W / V) at the end of fermentation; the concentration of gulonic acid of fermentation solution is raised by 10 percent to 15 percent; the conversion rates of alcohol and acid are respectively promoted by 3 percentage points; and stability is good; besides, the technique process has simple and convenient operation and is easy for wide application.

Description

technical field [0001] The invention relates to a preparation method of vitamin C, in particular to a high-concentration fermentation production process of 2-keto-L-gulonic acid. Background technique [0002] At present, many domestic manufacturers mainly use two-step fermentation technology for vitamin C production. The main feature of this technology is that the fermentation process is completed in two steps. The first step is to use black vinegar bacteria to convert D-sorbitol into L-sorbose, and the second step is to convert sorbose from sorbose under the action of a mixed strain For 2-keto-L-gulonic acid (vitamin C precursor). This mixed strain is composed of two kinds of microorganisms, among which the microorganism responsible for sugar-acid conversion was originally named Gluconobacter oxidans, and its taxonomic position was re-determined after systematic identification recently, and the bacteria was renamed as common ketogenic group Guronic acid bacteria; the othe...

AI Technical Summary

Problems solved by technology

The product concentration of this method is low, and the production capacity of the bacteria and equipment cannot be fully utilized.