【摘要】 目的:为了在枯草芽孢杆菌中整合表达极端耐热木聚糖酶。方法:将嗜热网球菌(Dictyoglomus thermophilum)Rt46B.1的极端耐热木聚糖酶基因xynB通过穿梭载体pDL整合到B.subtilis168染色体上,使其实现表达。结果:极端耐热木聚糖基因在枯草芽孢杆菌中成功整合并表达。结论:基因工程菌B.subtilis168-xynB能外泌表达极端耐热木聚糖酶,且表达水平为0.732IU/mL,比在大肠杆菌中的高。酶学性质表明,此酶分子量约为24kD,其最适反应温度为85℃,最适反应pH值为6.5,且在弱碱性条件下稳定。更多还原

【Abstract】 Objective: In order to expressive the extreme thermophile xylanase gene xynB from Rt46B.1(Dictyoglomus thermophilum).Method: The gene was cloned into the integration vectors of pDL and transform into host cell of B.subtilis 168.Result:The gene of xynB was recombinanted into chromatic body of B.subtilis 168 by double crossover homologous sequence substitution.Conclusion: The recombinant which has chlorampenicol resistance can express xylanase activity.Xylanase B(24kD) was successfully expressed(0.732IU/mL) with higher-level production than expression system of E.coli in LB.The recombinant protein of XynB expressed in B.subtilis 168 showed extreme thermostability and pH stability,which was optimally active at 85℃ and at pH 6.5.The recombinant XynB expressed in B.subtilis 168 is of great use in a variety of industrial and agricultural applications.更多还原