摘要
该研究拟采用枯草芽孢杆菌异源表达大麦来源β-淀粉酶。选择枯草芽孢杆菌WB800作为宿主,采用同源重组的方法构建表达载体pP43NMK-amyB,获得重组枯草芽孢杆菌WB-amyB。重组枯草芽孢杆菌在摇瓶发酵条件下酶活最高可达386U/mL,纯化后测得其比酶活为613U/mg。重组酶的最适温度为55℃,最适pH值为5.0。重组β-淀粉酶水解产麦芽糖能力与大麦β-淀粉酶相当,与普鲁兰酶联用时麦芽糖最大转化率可达81.8%。重组枯草芽孢杆菌摇瓶发酵水平产酶量高于类似文献报道,重组β-淀粉酶的酶学性质与大麦β-淀粉酶相比几乎相同,完全可以替代大麦β-淀粉酶在工业上的应用。
In this study,barleyβ-amylase was heterologously expressed in Bacillus subtilis.The expression vector pP43NMK-amyB was constructed and transformed into B.subtilis WB800 and a recombinant B.subtilis WB-amyB was obtained.A maximum yield of 386 U/mLβ-amylase was obtained in shaking flask fermentation.The purified enzyme had the specific activity of 613 U/mg.Its optimal reaction temperature and pH were 55℃and 5.0,respectively.The hydrolysis ability of recombinantβ-amylase towards starch was similar to that of barleyβ-amylase.When it was combined with pullulanase,the maximum conversion rate of starch to maltose reached 81.8%,therefore,the recombinant barleyβ-amylase can completely replace barleyβ-amylase in industrial application.
作者
汪薛良
钮成拓
包敏
李崎
王金晶
WANG Xueliang;NIU Chengtuo;BAO Min;LI Qi;WANG Jinjing(Lab of Brewing Science and Technology,Jiangnan University,Wuxi 214122,China;School of Biotechnology,Jiangnan University,Wuxi 214122,China)
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2019年第14期34-40,共7页
Food and Fermentation Industries
基金
江苏省现代工业发酵协同创新中心项目
江苏高校品牌专业建设工程资助项目
国家自然科学基金项目(No.31571942,No.31601558)
