Method for preparing 2-keto-L-gulonic acid

Abstract

The invention discloses a method for preparing 2-keto-L-gulonic acid. The method is characterized by comprising the steps of: independently cultivating large bacteria, successively carrying out microfiltration and ultrafiltration treatment on the obtained large bacteria fermentation liquor to obtain an active substance concentrated solution; and feeding the obtained active substance concentrated solution of the large bacteria to a small bacteria culture medium to promote small bacteria to convert sorbose into 2-keto-L-gulonic acid. By adopting the method, the large bacteria are independently cultivated; preferably, the large bacteria are synchronously cultivated, so that the optimum growth condition of the large bacteria can be met; the production efficiency is improved; an active enzyme substance of the large bacteria is collected to transfer into small bacteria fermentation liquor by adopting advanced microfiltration and ultrafiltration technologies; bottom sugar and pH of the small bacteria fermentation liquor can be further stabilized by feeding the sorbose solution and a pH maintaining agent; the quantity of the small bacteria is increased; the growth time of thallus is shortened; the reaction rate of converting the sorbose oxidized by the small bacteria into 2-KLG is quickened; the fermentation cycle is shortened; the concentration of a product is improved; the production cost is reduced; and the market competitiveness of an enterprise is improved.

Description

technical field

[0001] The present invention relates to a preparation method of a vitamin C precursor - 2-keto-L-gulonic acid (2-KLG), in particular to separately cultivating large and small bacteria under optimal conditions to produce 2-keto- The method for L-gulonic acid belongs to the technical field of vitamin C production. Background technique

[0002] Vitamin C, also known as L-ascorbic acid, can participate in various redox reactions and hydroxylation reactions in the body. Blood disease, enhance the body's resistance. Green plants can synthesize vitamin C by themselves. However, humans and many animals cannot synthesize vitamin C by themselves due to the lack of gurolactone oxidase in their livers, and must ingest it from the outside. At present, vitamin C has been widely used in the fields of medicine, food, health care products and cosmetics. And with the development of its use and the improvement of people's material and cultural living standards, the demand fo...