Method adding trehalose to strengthen production strength of 2-keto-L-Gulonic acid

Abstract

The invention discloses a method adding trehalose to strengthen production strength of 2-keto-L-Gulonic acid, belonging to the technical filed of ferment preparation of vitamin C. The invention takesthe mixing strain of Ketogulonigenium vulgare and Bacillus megaterium as a production strain, and 10mmol.L<-1> of trehalose is exogenously added into fermentation culture medium to be used as protective agent, therefore, the cell growth and production of 2-keto-L-Gulonic acid (2-KLG) are promoted, and the efficient production of 2-KLG is realized. When 10mmol.L<-1> of trehalose is added under a hyperosmotic condition (1067.5mOsmol.kg<-1>), the content of 2-KLG is 56.83g.L<-1> at 72h, which is 1.94 times of the content of 2-KLG of a matched group that adds no trehalose under the hyperosmotic condition, wherein the content of 2-KLG of the matched group is 29.24g.L<-1>. When 10mmol.L<-1> of trehalose is added under a normal fermentation condition adding no NaCl, the fermentation period is shortened to 52h, the end point acid production is up to 69.38g.L<-1>, and the consumption speed of L-sorbose and the production intensity of 2-KLG are respectively increased by 43.1% and 45.5%.

Description

technical field [0001] The invention discloses a method for adding trehalose to enhance the production strength of 2-keto-L-gulonic acid, which belongs to the technical field of vitamin C preparation by fermentation. Background technique [0002] Vitamin C (i.e. L-ascorbic acid) is an essential vitamin for the human body. It has a wide range of physiological functions. It has important uses in medicine and food industry, and occupies a very important position in the production of vitamin drugs. At present, the production of vitamin C in my country mainly adopts the "two-step fermentation method". The main feature of this process is that the second step of fermentation, that is, the conversion from L-sorbose to 2-keto-L-gulonic acid (2-KLG) needs to be produced by Ketogulonigenium vulgare (commonly known as "small bacteria") Combined with Bacillus megaterium (commonly known as "big bacteria") for mixed fermentation. [0003] Although the "two-step fermentation method" repla...

AI Technical Summary

Problems solved by technology

At present, the addition of trehalose to improve the tolerance of mixed strains to hypertonicity, thereby enhancing the production intensity of 2-KLG has not been reported in the literature