Xylanase Gene from Bacillus Subtilis B10

Bacillus subtilis B10 was isolated for ramie degumming from the soil around dew-rotten ramie.The xylanase gene of Bacillus subtilis B10 was cloned by PCR.The positive clones were screened on the selected LB agar plates supplemented with xylan by Congo-red staining method.The recombinant plasmid from one positive clone was used for further characterization and DNA sequencing.The full-length of the xylanase gene has 642 bp and the deduced amino acid sequence has 214 residues.The gene is different from the reported xylanase gene of Bacillus subtilis in sie of two base pairs.In Eschericia coli,the xylanase gene could be expressed by the recombinant plasmid and the xylanase activity distribution in extracellular,intracellular and periplasmic fractions were 22.7%,28.2% and 49.1% respectively.The xylanase has optimal activity at pH6.0 and 50℃,and has a broader pH profile and better tempreture stability.