中文摘要：

研究耐碱性短小芽孢杆菌木聚糖酶在枯草芽孢杆菌中异源表达。从耐碱性木聚糖酶高产短小芽孢杆菌BYG5—20中克隆得到带有自身启动子的木聚糖酶基因xynA，将其构建在大肠杆菌-枯草芽孢杆菌穿梭载体pGJ148中得到重组质粒pGJ148-xynA。采用电转化法将重组质粒pGJ148-xynA转入枯草芽孢杆菌1A747中，得到重组菌电．GJ148-xynA，然后进行诱导表达以及培养基的优化。重组菌GJ148～xynA发酵上清液中木聚糖酶酶活可达93．32IU／ml。耐碱性短小芽孢杆菌木聚糖酶基因xynA可以在枯草芽孢杆菌中实现异源表达，为枯草芽孢杆菌木聚糖酶分泌表达系统的进一步优化奠定了基础。

英文摘要：

This research aimed to study the heterologous expression of alkali resistance xylanase gene xynA in bacillus subtilis, alkali resistance xylanase gene xynA with original signal peptide was separated from bacillus pumilus BYG5-20,then was cloned into the secreted expression vector pGJ148 to construct a recombinant plasmid pGJ148-xynA.The plasmid was transformed into bacillus subtilis 1A747 and recombinant strain B.GJ148-xynA was obtained .The inducible expression of xynA was assayed and the fermentation conditions was optimized. The xylanase activity of the culture supernatant of recombinant strain was up to 93.32 IU/ml after induction expression and medium optimization.Heterologous expression of xynA gene in bacillus subtilis was succeed and the bacillus subtilis xylanase secretion expression system was expected to be further optimized.