耐碱性木聚糖酶基因在短小芽孢杆菌中高效分泌表达的研究

Secreted Overexpression of Alkali-tolerant Xylanase Gene in Bacillus pumilus

从木聚糖酶高产短小芽孢杆菌 (Bacilluspumilus)BP5 1中克隆得到木聚糖酶基因xynA ,将其构建在芽孢杆菌表达载体pWH1 5 2 0中得到重组质粒pWSX1 1。xynA由木糖诱导xylA启动子调控xynA表达。采用同源高效表达策略 ,以原生质体转化方法将pWSX1 1转回原始菌株BP5 1中 ,获得重组菌株BPX1 1。通过木糖诱导重组菌株中的xy nA基因高效分泌表达 ,使木聚糖酶产酶活力比原菌株BP5 1提高了 87% 。

The xylanase encoding gene xynA was cloned from Bacillus pumilus BP51, a xylanase over producer. The xynA gene was inserted in Bacillus expression vector pWH1520, downstream of xylA promoter.The recombinant plasmid pWSX11 was transformed back into the original strain B.pumilus BP51 and the recombinant B.pumilus BPx11 was obtained.The xynA was over expressed and the xylanase was secreted into medium. The xylanase activity produced by recombinant BPX11 had increased about 87% as compared with the original strain BP51 The properties of the recombinant xylanase were characterized.