Abstract：The Xyn2 gene, which encodes the main Trichoderma reesei Rut C-30 endo-β-1, 4-xylanase was successfully cloned into the pPICZαA vector and expressed in Pichia pastoris. The desired P. pastoris strains produced β-xylanase under the control of the methanol inducible alcohol oxidase 1 (AOX1) promoter, and the secreted recombinant Xyn2 was estimated by SDS-PAGE as 21 kDa. The activity of the recombinant Xyn2 was highest at 60℃ which was 5℃ higher than native xylanse. In addition, the recombinant Xyn2 was active over a broad range of pH 3.0-8.0 with maximal activity at pH6.0. The enzyme was quite stable at 50℃ and retained more than 95% of its activity after 30 mins incubation at this temperature. These properties should make the enzyme an attractive candidate in various industrial applications.
