Novel glucose oxidase mutant

Abstract

The invention relates to the technical field of genetic engineering, and specifically provides a glucose oxidase mutant. According to the present invention, the heat resistance of the glucose oxidasesingle-point mutant is generally higher than the heat resistance of wild type glucose oxidase, the residual enzyme activity of the glucose oxidase single-point mutant is increased by 17.5-72.7% aftertreatment for 10 min at a temperature of 60 DEGC, and the residual enzyme activity of the glucose oxidase single-point mutant is increased by 23.8-100.4% after treatment for 5 min at a temperature of65 DEGC, such that the heat resistance of glucose oxidase is substantially improved due to the single-point mutation, the glucose oxidase single-point mutant can be well used as the feed additive compared to the wild type glucose oxidase, and the wide applications of glucose oxidase in feed can be easily achieved so as to provide wide market prospect.

Description

technical field [0001] The invention belongs to the technical field of genetic modification, and in particular relates to a novel mutant of glucose oxidase. Background technique [0002] Glucose oxidase is an aerobic dehydrogenase that specifically oxidizes β-D-glucose to generate gluconic acid and hydrogen peroxide. Glucose oxidase usually forms a redox system with catalase, oxidizes β-D-glucose in the presence of molecular oxygen to generate D-gluconolactone, and consumes oxygen to generate hydrogen peroxide. Catalase decomposes hydrogen peroxide to generate water and 1 / 2 oxygen, and then the water combines with gluconolactone to produce gluconic acid. Glucose oxidase shows strong specificity to β-D-glucopyranose. The hydroxyl group on glucose molecule C1 is crucial to the catalytic activity of the enzyme, and the hydroxyl group at the β position is 160 times higher than that at the α position. Glucose oxidase is completely inactive on L-glucose and 2-O-methyl-D-glucose....

AI Technical Summary

Problems solved by technology

However, the thermal stability of glucose oxidase derived from Aspergillus niger is poor, and its aqueous solution is kept at 65°C for 5 minutes, and the remaining enzyme activity is less than 40%, which limits the application of this enzyme in pellet feed

At present, the method of spraying glucose oxidase liquid onto the feed after feed granulation not only increases equipment investment, but also cannot guarantee the stability of the enzyme preparation and the uniformity of the distribution of the enzyme preparation in the feed

Images