Method for screening guanosine high-yielding strains through membrane culture

Abstract

The invention relates to a method for screening guanosine high-yielding strains, comprising the following steps of: (1) adding sterile purified water to guanosine producing strains to be screened and rejuvenated, placing on an oscillator, and uniformly mixing to prepare suspension solution with the dilution degree of 10-2-10-7; (2) inoculating the suspension solution to a membrane culture system, and standing for culture; (3) judging according to the size and the shape of a bacterial colony of the guanosine producing strains inside the membrane culture system, and primarily screening the guanosine high-yielding strains and negative variation strains. The invention has the advantage that the guanosine high-yielding strains screened through the method achieve 18-20 g / L of glycosides produced through shake-flask culture; and in addition, the method is novel, easy and convenient to implement and far higher than the traditional screening method in screening accuracy rate and plays optimizing roles in efficiency increase, accuracy rate enhancement and workload reduction on daily separation and screening work of the guanosine high-yielding strains in factories.

Description

technical field [0001] The invention belongs to the field of bioengineering, and specifically relates to a method for screening high-yield bacteria of Guanosine. Background technique [0002] Guanosine is also known as guanine nucleoside or 9-(β-D-ribofuranosyl) guanine (9-(β-D-Ribofuranosyl) guanine guanine-9-β-D-ribofuranoside (Guanine-9- β-D-ribofuranoside). Guanosine has a wide range of uses and can be used to synthesize food freshness enhancers—disodium 5'-guanylate, disodium nucleotides with taste, and as an important intermediate of pharmaceutical products, which can form a A series of downstream pharmaceutical products, including nucleoside antiviral drugs such as ribavirin, acyclovir, etc., are also used in the manufacture of acyclovir (Acyclovir), ribavirin (ATC), guanosine triphosphate The main raw material of drugs such as sodium (GTP). Xiaoxi et al., by releasing the feedback inhibition of IMP dehydrogenase, the selected mutant strains resistant to 8-azaguanine...

AI Technical Summary

Problems solved by technology

[0003] However, because the guanosine-producing bacteria are defective production strains, the high-yielding guanosine strains inevitably undergo negative changes during preservation, production, and subculture, resulting in the loss of guanosine Yield declines, regular screening and rejuvenation are necessary

However, the traditional dilution plate method is difficult to distinguish high-yield and negative mutant strains from the colony morphology. The initial screening is blind, which increases the workload, but the accuracy is not high, resulting in long screening cycle and repeated work.

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