γ-CGTase突变体制备及其产γ-CD条件优化  

Preparation of γ-CGTase Mutant and Optimization of the Production of γ-CD

作　　者：王金鹏[1,2,3] 王萍 苑征 李林林[1,2,3] 范浩然 金征宇[1,2,3] WANG Jinpeng;WANG Ping;YUAN Zheng;LI Litdin;FAN Haoran;JIN Zhengyu(State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi 214122,China;School of Food Science and Technology,Jiangnan University,Wuxi 214122,China;Collaborative Innovation Center of Food Safety and Nutrition,Jiangnan University,Wuxi 214122,China)

机构地区：[1]食品科学与技术国家重点实验室,江南大学,江苏无锡214122 [2]江南大学食品学院,江苏无锡214122 [3]食品安全与营养协同创新中心江南大学,江苏无锡214122

出　　处：《食品与生物技术学报》2018年第10期1015-1020,共6页Journal of Food Science and Biotechnology

基　　金：国家自然科学基金项目(31401524);江苏省自然科学基金项目(BK20140143)：国家“十二五”科技支撑计划项目(2012BAD37B03);江苏省科技支撑计划项目(BE2013311);农业部公益性行业(农业)科研专项(201303070-02);江苏高校优势学科建设工程资助项目.

摘　　要：采用定点突变法将来自Bacillussp.G-825-6的γ-CGTase的211位的酪氨酸突变为亮氨酸,并利用突变体Y211L催化淀粉制备γ-CD,分别研究了底物种类、底物质量分数、反应时间、反应温度、加酶量对γ-CD产率的影响,并在单因素的基础上进行了正交优化,优化后的反应条件为:木薯淀粉质量分数为6%,加酶量为4 U/g,反应温度50℃,反应时间为24 h,在此条件下催化产生γ-CD的产率可达到14%,以总环糊精质量分数为100%计,催化产γ-CD的比率为97%。In this thesis,tyrosine 211 of T-CGTase from Bacillus sp. G-825-6 changed into leucine based on site-directed mutagenesis. The influences of substrate type,concentration,time, temperature, and enzyme concentration on the mutant Y211L catalyticed starch to produced γ-CD were evaluated. On the basis of single of factor experiments, orthogonal design method was used to optimize the condition for production of γ-CD. As a result, the best condition was： cassava starch 6% ,enzyme concentration 4 u/g,temperature 50 ℃ ,time 24 h. Under thses conditions,the production of γ-CD can reach 14%. If the total cyclodextrin content is 100% ,the catalytic production ratio of γ-CD is 97%.

关 键 词：CGTASE γ-CD 定点突变 产物专一性 

分 类 号：TS239[轻工技术与工程—粮食、油脂及植物蛋白工程]