A screening method and application of high-efficiency endoxylanase producing bacteria

Abstract

The present invention provides a screening method and application of high-efficiency endoxylanase-producing bacteria, including: (1) sample source; (2) bacterial strain screening; (3) preparation of xylanase fermentation liquid and other steps. The invention first isolates and cultivates the strains in the growth medium, and then uses the double-layer plate method to screen the strains. Azo-xylan (Birchwood) is added to the upper medium as the screening substrate. This method can solve the problem of first cultivating microorganisms, and then adding Congo The problem of mixing between colonies during the color reaction of the red solution can also solve the problem of false positives in the process of adding Congo red when preparing the plate and then culturing the microorganisms.

Description

A kind of screening method of high-efficiency endo-xylanase-producing bacteria and its application technical field The invention belongs to biotechnology field, be specifically related to a kind of screening method of endo-xylanase producing bacteria and the same application. Background technique Hemicellulose is a very abundant resource in nature, accounting for about 35% of the dry weight of plants, and it is widely present in Agricultural and sideline products such as corn cob, wheat bran, rice bran, straw and bagasse are second only to cellulose in nature. Xylan is An important part of hemicellulose is the main chain composed of β-D-xylpyranose units connected by β-1,4-glycosidic bonds. There are many different substituents such as acetyl group, arabinose residue and glucose residue on it, and the source or branching degree is different. A complex and diverse xylan molecule composed of main side chains and different substituents. Complete degradation of xylan...

AI Technical Summary

Problems solved by technology

[0003] At present, the screening of xylan-degrading strains mostly uses the Congo red staining method, mainly through two methods, one way is to culture microorganisms first, then add Congo red solution for color reaction, and then decolorize by sodium chloride to form xylans of different sizes. Sugar degradation transparent circle, the advantage of this method is that the displayed color reaction is basically the effect of xylan degrading bacteria, the disadvantage is that this method is cumbersome to operate, adding Congo red solution will cause mixing between colonies; another method It is to add Congo red when preparing the plate. The advantage of this method is that it is easy to operate and there is no problem of colony mixing. The disadvantage is that agar and potato juice contain starch substances, which can cause false positive reactions in microorganisms that produce amylase. In addition, some Some microorganisms with the ability to degrade pigments will degrade Congo red and form a transparent circle during the long-term culture process, which is not easy to distinguish from xylan-degrading bacteria

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