米黑根毛霉α-淀粉酶的定向进化、高效表达及在面包中的应用  

Directed Evolution and High-Level Expression of α-Amylase from Rhizomucor miehei and its Application in Bread

作　　者：王玉川 马俊文 李延啸[2] 刘海杰[1] 闫巧娟[2] 江正强[1,3] Wang Yuchuan;Ma Junwen;Li Yanxiao;Liu Haijie;Yan Qiaojuan;Jiang Zhengqiang(Key Laboratory of Food Bioengineering(China National Light Industry),College of Food Science&Nutritional Engineering,China Agricultural University,Beijing,100083;College of Engineering,China Agricultural University,Beijing,100083;College of Food Science and Engineering,Nanjing University of Finance and Economics/Collaborative Innovation Center for Modern Grain Circulation and Safety,Nanjing 210023)

机构地区：[1]中国农业大学食品科学与营养工程学院、中国轻工业食品生物工程重点实验室,北京100083 [2]中国农业大学工学院,北京100083 [3]南京财经大学食品科学与工程学院、江苏省现代粮食流通与安全协同创新中心,南京210023

出　　处：《中国粮油学报》2022年第11期78-85,共8页Journal of the Chinese Cereals and Oils Association

基　　金：国家重点研发计划(2021YFC2100302)。

摘　　要：本研究利用定向进化技术对米黑根毛霉(Rhizomucor miehei)来源的α-淀粉酶(RmAmy)进行分子改造,随后对突变酶进行高效表达和在面包中的应用。突变酶(mRmAmy)的最适pH和温度分别为5.0和65℃,比野生型下降1.0 pH和10℃;该酶在pH 4.0~10.0和60℃以下稳定。mRmAmy经高密度发酵168 h,酶活力最高达11 900 U/mL。mRmAmy应用于面包制作中,在加酶量为3 mg/kg时,面包比容增加14.4%,硬度减小25.8%。结果表明mRmAmy在烘焙工业中具有很大的应用潜力。Directed evolution was employed to modify the properties of the α-amylase(RmAmy) from Rhizomucor miehei, then the mutant(mRmAmy) was efficiently expressed and the application of mRmAmy in bread was evaluated. The optimal pH and temperature of mRmAmy were 5.0 and 65 ℃, respectively. Compared with wild-type, one unit of the optimal pH was shifted to acidic condition, and the optimal temperature was reduced by 10 ℃. The mRmAmy was stable within pH 4.0~10.0 and up to 60 ℃. After 168 h high-cell density fermentation, the highest α-amylase activity was 11 900 U/mL. Addition of 3 mg/kg mRmAmy in bread caused 14.4% increase in specific volume and 25.8% decrease in hardness in comparison to the control. The results indicated that mRmAmy has great application potential in the baking industry.

关 键 词：米黑根毛霉 Α-淀粉酶 定向进化 高密度发酵 面包 

分 类 号：TS236.9[轻工技术与工程—粮食、油脂及植物蛋白工程]