构建枯草芽孢杆菌信号肽筛选载体并用菌体自身信号肽引导表达外源木聚糖酶基因,为枯草芽孢杆菌木聚糖酶高效分泌表达系统的建立奠定基础。利用基因工程的原理和方法,将壮观霉素抗性基因(spec)与短小芽孢杆菌的木聚糖酶基因(xynA)克隆到大肠杆菌-枯草芽孢杆菌穿梭表达载体GJ148上,构建枯草芽孢杆菌信号肽筛选载体pYG,将枯草芽孢杆菌信号肽Epr克隆到已构建载体上,以枯草芽孢杆菌WB700为表达宿主,引导木聚糖酶基因进行表达。最终成功构建枯草芽孢杆菌信号肽筛选载体pYG,将枯草芽孢杆菌信号肽Epr克隆到pYG上,在WB700中引导并表达木聚糖酶基因。试验证明信号肽筛选载体可以成功构建,在克隆入信号肽后可成功表达木聚糖酶基因,为信号肽的系统性筛选和木聚糖酶高效表达提供依据。
To establish an efficient expression system of xylanase in Bacillus subtilis,a screening vector of signal peptides from Bacillus subtilis was constructed,and a xylanase gene xynA was expressed by one of signal peptides cloned on it.In the experiment,xynA was amplified from the genome of Bacillus pumilus and cloned into E.coli and B.subtilis Shuttle Vector GJ148,resistance gene of spectinomycin was also cloned into it.A signal peptide(Epr) was cloned into the constructed screening vector pYG for the expression of xynA gene in Bacillus subtilis WB700.The screening vector pYG was successful constructed,and the signal peptide(Epr) successful mediated the expression of xynA gene in Bacillus subtilis WB700.This experiment showed the possibility of constructing a screening vector for all signal peptides from Bacillus pumilus,it could successful express xylanase gene with cloned signal peptide.This conclusion will be helpful for systemic screening of all signal peptides from Bacillus subtilis and efficient xylanase expression.