地衣芽胞杆菌α-淀粉酶耐热耐酸突变体的酶学性质  

Biochemical characterization of heat-and acid-resistant mutant of Bacillus licheniformis α-amylase

作　　者：刘雪莲 申培立 牛丹丹 金鹏 田康明 王正祥 LIU Xuelian;SHEN Peili;NIU Dandan;JIN Peng;TIAN Kangming;WANG Zhengxiang(College of Chemical Engineering and Materials Science,Tianjin University of Science and Technology,Tianjin 300457,China;College of Biotechnology,Tianjin University of Science and Technology,Tianjin 300457,China)

机构地区：[1]天津科技大学化工与材料学院,天津300457 [2]天津科技大学生物工程学院,天津300457

出　　处：《食品与发酵工业》2020年第2期7-10,共4页Food and Fermentation Industries

基　　金：国家重点研发计划政府间国际科技创新合作重点专项(2018YFE0100400);天津市高等学校创新团队建设规划(TD12-5002);天津市科技计划项目(19YFZCSN00560)

摘　　要：地衣芽胞杆菌α-淀粉酶(Bacillus licheniformisα-amylase,BLA)的耐热耐酸性特征,是其在淀粉酶法加工中最重要的应用属性。在通过人工进化获得BLA突变体V-2的基础上,该研究对其酶学性质进行了较全面的分析。突变体V-2在80℃和pH 5.5下表现出最高酶活力,最适作用温度和pH较BLA提高了10℃和降低了0.5~1.0个pH值,其耐热性和耐酸性显著优于BLA,该突变体的酶活力对金属离子特别是Ca 2+的依赖性显著降低,该酶对淀粉水解作用明显优于BLA,其催化效率是BLA的33倍。The heat-and acid-resistance of Bacillus licheniformisα-amylase(BLA)is the most important application property for enzymatic processing of starch.In this study,biochemical properties of mutant V-2 obtained by artificial evolution were comprehensively analyzed.V-2 showed the highest enzyme activity at 80℃and pH 5.5,which was 10℃higher and 0.5-1.0 pH lower than that of BLA,respectively.Its heat and acid resistance were significantly improved.The effects of metal ions,especially Ca 2+,on the activity of V-2 were significantly reduced.V-2 was significantly more efficient than BLA in starch hydrolysis,with its catalytic efficiency 33 folds higher than that of BLA.

关 键 词：高温Α-淀粉酶 地衣芽胞杆菌 进化 耐热性 耐酸性 

分 类 号：Q55[生物学—生物化学] TQ925.1[轻工技术与工程—发酵工程]