Method for establishing recombinant bacillus subtilis for expressing thermophilic xylanase

The invention discloses a method for establishing recombinant bacillus subtilis for expressing thermophilic xylanase and relates to a method for establishing microorganism recombinant bacteria. The method comprises the following steps: firstly, designing primers according to an endo-1,4-beta-xylanase gene of thermopolyspora flexuosa, performing enzyme digestion after PCR amplification is succeeded, connecting carrier plasmid pHT43, amplifying by using escherichia coli DH5alpha, selecting positive clone, performing thallus PCR and sequencing verification, massively extracting plasmid which is correct through gene sequencing, transforming, leading in a bacillus subtilis WB800N host, culturing, performing induced expression by using 1mMIPTG, and performing SDS-PAGE electrophoresis on the fermented liquid supernate, thereby proving that the recombinant protein of endo-1,4-beta-xylanase is successfully expressed. The relative molecular weight of the recombinant protein is 27KD, the optimal reaction temperature of the recombinant protein is 80 DEG C, and the optimal reaction pH of the recombinant protein is 6.0. The endo-1,4-beta-xylanase can be widely used in the paper-making industry and the food industry.