Fermentation medium and method for fermentation production of uridine phosphorylase using the same

Abstract

A fermentation medium comprises: NaCl (3-12 g / L), glucose (10-25 g / L), extract yeast (5-15 g / L), peptone (2-15 g / L), K2HPO4-H2O (1 / 3) (2-5 g / L), uridine (7-25 mmol / L), inosine (15-30 mmol / L) and double distilled water. A fermentation method based on the fermentation medium comprises: streaking, inoculating and culturing lactobacillus brevis for 12-48 h, preserving at 4 DEG C for a standby application; taking and dissolving a certain amount of extract yeast in double distilled water, adjusting pH at 6.0-8.0, disinfecting at 121 DEG C for 15-20 min, and obtaining an activating solution containing 1-10% by mass of extract yeast; picking lactobacillus brevis, inoculating to the activating solution, activating at 30-40 DEG C for 4-12 h, and obtaining activated lactobacillus brevis thalluses; inoculating the lactobacillus brevis thalluses to the fermentation medium with an inoculation volume of 1-10% by volume; fermenting for 4-12 h with a medium temperature of 30-40 DEG C and a shaking-table rotating speed of 90-180 r / min, and obtaining a fermentation liquor; centrifuging the fermentation liquor for 10-30 min with a speed of 3000-5000 r / min, in a centrifuge tube obtaining a deposition which is the fermented whole-cell lactobacillus brevis wet thallus, and taking the fermented whole-cell lactobacillus brevis wet thallus as a uridine phosphorylase source to carry out nucleosides fermentation.

Description

technical field [0001] The invention relates to the field of microbial engineering, in particular to a fermentation medium suitable for the growth of Lactobacillus brevis and high production of uridine phosphorylase and a fermentation method thereof. Background technique [0002] Uridine phosphorylase is a homohexamer (6×27.5 ku), which widely exists in animals, plants and microorganisms, participates in cellular nucleic acid metabolism pathways, and catalyzes the reversible phosphorylation of uridine in the “remedial pathway” to provide ribose -1-phosphate, releasing the base uracil. Therefore, uridine phosphorylase plays an important role in the biosynthesis of nucleoside drugs, and the synthesized nucleoside drugs are widely used in the field of medicine, such as antiviral and antitumor nucleoside drugs. [0003] At present, some uridine phosphorylase-producing strains such as Enterobacter aerogenes and Brevibacterium acetylene with high enzyme activity have been obtaine...

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Problems solved by technology

[0003] At present, some uridine phosphorylase-producing strains with high enzyme activity such as Enterobacter aerogenes and Brevibacterium acetylene have been obtained through traditional screening and mutagenesis techniques, but these strains not only have certain pathogenicity Moreover, the amount of enzyme produced is low, and the proportion of various enzymes is uncoordinated, which seriously limits their application in industrial production.