酸性α-淀粉酶是发酵行业用量最大的酶类,为了实现酸性α-淀粉酶基因的高效表达,将本实验室已经克隆得到的去信号肽的酸性α-淀粉酶基因在枯草芽孢杆菌WB600宿主中进行表达,成功的构建了表达菌株pHT43-amy/WB600。在初始菌浓度OD600为0.8时加入终浓度为0.9 mmol/L的IPTG,诱导6 h的条件下测得酶活力为1 230 U/mL,又由于宿主菌WB600外分泌蛋白较少,因此具有明显的生产优势。

Acid-stable α-amylase is widely used in fermentation industry.In order to highly express acid-stable α-amylase gene,a recombinant vector containing no signal peptide of acid-stable α-amylase gene from Bacillus amyloliquefaciens was constructed followed by transformation into Bacillus subtilis WB600 host.The highest activity of recombinant acid-stable α-amylase was 1230 U/mL under the condition as follows: OD600 of the initial bacteria was 0.8 and final concentration of IPTG was 0.9 mmol/L,and the cell suspension was cultured for 6 hours after addition of IPTG.As the recombinant Bacillus subtilis WB600 secreted few other proteins except the targeted acid-stableα-amylase,it showed obvious advantages in amylase production.