2 results about "Pseudomonas denitrificans" patented technology

The invention relates to a high-yield vitamin B12 strain with improved robustness and application of the high-yield vitamin B12 strain, and belongs to the technical field of microbial fermentation and metabolic engineering. According to the invention, a pseudomonas denitrificans original production strain capable of synthesizing the vitamin B12 is evolved by a long-term adaptive laboratory taking the vitamin B12 and a structural analogue thiamine hydrochloride thereof as selection pressure. The evolved strain shows significantly enhanced growth ability and fermentation stability in a high stress environment, and the highest yield of vitamin B12 can reach 314 mg / L, which is 38.7% higher than that of an original strain, which is the highest level reported at present. Moreover, stable production can be realized on a 7 L fermentation tank, and good batch stability is realized. The invention also provides application of the strain in industrial production of the vitamin B12, and the strain has important significance in reducing the production cost of the vitamin B12 and improving the fermentation efficiency.

The present application provides a kind of fermentation method for improving the content of vitamin B12, by controlling total sugar content to be 1.0-7.0g / 100ml in the fermentation process, under the condition that 5-amino levulinic acid is added in the fermentation process of producing vitamin B12 in the fermentation medium by using Pseudomonas denitrificans, the metabolic pathway of vitamin B12 product synthesis is greatly strengthened.The fermentation method of the present application shortens the fermentation period and effectively improves the fermentation titer in the fermentation process of producing vitamin B12, and has great industrial application prospect.