A high-temperature resisting neutral xylanase gene and engineering bacteria containing the gene

Abstract

The invention relates to a high-temperature resisting neutral xylanase gene and engineering bacteria containing the gene. A gene sequence refers to a sequence 1, the whole length of the gene is 1134 bp and the gene is named as XynG1-1, the gene codes 377 amino acids, molecular weight of the gene is 41267 Da, wherein former 39 amino acids are signal peptide of the gene, the 49th to 235th amino acids are a conserved sequence of a glucosides hydrolase GH11 family, the 263rd to 377th amino acids are a conserved sequence of a carbohydrate-binding module CBM6 family. According to the invention, the recombinase obtained by fermenting the engineering bacteria has optimum temperature of 60 DEG C and optimum pH value of 7.0, heat is preserved at a pH value of 7.0 and temperature of 70 DEG C for 1 hour, the relative enzyme activity is more than 65%, and heat is preserved at a pH value of 9 and temperature of 60 DEG C for 1 hour, the relative enzyme activity is more than 60%. The xylanase of the present invention has the characteristic of good stability under high temperature, and can be applied to a plurality of industrial fields such as papermaking, foodstuff and forage, etc. The present invention has wide application prospect.

Description

technical field [0001] The invention belongs to the field of bioengineering, in particular to a high-temperature resistant neutral xylanase gene and engineering bacteria containing the gene. Background technique [0002] Xylanase (1,4-β-D-xylanase; EC3.2.1.8) is an important industrial enzyme, which has shown broad application prospects in the fields of paper industry, food, energy, feed and environment , especially the huge application potential in pulp biobleaching has already attracted great attention from all walks of life. The function of xylanase treatment of various pulps is to degrade the xylan in the pulp, reduce the content of hemicellulose in the pulp, relax the cellulose cell wall structure, and at the same time make the residual lignin connected with the pulp Hemicellulose degrades to form delignification or a state conducive to delignification. The pretreatment of xylanase can not only improve the whiteness of pulp, reduce the energy consumption of beating, i...

AI Technical Summary

Problems solved by technology

A number of enzyme preparation manufacturers such as Novozymes of Denmark and Sandaus Chemical Company of the United States have launched new products of xylanase and cellulase specially used for pulp treatment, but so far, the industrially used for pulp bleaching Most xylanases are neutral and slightly acidic, and the optimum reaction temperature is mostly around 50°C. As we all know, pulp cooking and bleaching are basically carried out under the conditions of high temperature and strong alkali, so that the existing low-temperature acidic xylanase The application of carbohydrase products in this field has been greatly limited. In addition, in the field of feed and food, xylanase is used in the granulation of feed and the baking process of food, and it is still required that the xylanase used in high temperature High enzyme activity can be maintained under certain conditions, therefore, the research and development of high temperature resistant xylanase products will bring good economic and social benefits

Images