Alkalic xylanase gene and engineering bacterium containing same

Abstract

The invention relates to an alkalic xylanase gene and an engineering bacterium containing the same. The alkalic xylanase gene has the overall length of 687 bp, is called XynG1-3, encodes 228 amino acids and predicts that the molecular weight of the amino acids is 25444Da, wherein the first 27 amino acids are signal peptides of the alkalic xylanase gene, and 38th-221st amino acids are conserved sequences of a glycoside hydrolase GH11 family. Compared with a reported xylanase gene sequence, individual nucleotides of the obtained and expressed alkalic xylanase gene are different; the optimal operative temperature and the optimal pH of the recombinase are respectively 55 DEG C and 8.0, relative enzyme activity is more than 50 percent after preserving heat at the pH of 9.0 and 60 DEG C for 1 hour, and the relative enzyme activity is more than 70 percent after preserving the heat under the conditions of the pH of 6-9 and the temperature of 55 DEG C for 1 hour.

Description

technical field [0001] The invention belongs to the field of bioengineering, in particular to an alkaline xylanase gene and an engineering bacterium 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 application of xylanase to treat various pulps directly degrades the xylan in the pulp, reduces the content of hemicellulose in the pulp, and relaxes the cell wall structure of the cellulose. Degradation of the hemicellulose linked to the cellulose leads to 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, improve the strength performance of pulp...

AI Technical Summary

Problems solved by technology

But so far, most of the xylanases used in the industry for pulp bleaching 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 at high temperature and strong alkali. Carry out under the condition, make the application of existing acidic or neutral xylanase product in this field be restricted greatly, therefore, research and development more alkaline xylanase product will bring good Economic and Social Benefits

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