重组Bacillus stearothermophilusβ-CGTase在β-环糊精制备中的应用条件优化  

Studies on Preparation of β-Cyclodextrin Production Using Bacillus stearothermophilus β-Cyclodextrin Glycosyltransferase and Reaction Conditions Optimization

作　　者：范博望 段绪果[1,2] 吴敬[1,2] FAN Bowang;DUAN Xuguo;WU Jing(State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi 214122,China;School of Biotechnology,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]江南大学生物工程学院,江苏无锡214122

出　　处：《食品与生物技术学报》2018年第9期897-902,共6页Journal of Food Science and Biotechnology

基　　金：国家自然科学基金项目(31425020,31401636,31271813);中国博士后基金项目(2015M580390);江苏省自然科学基金项目(BK20140142)。

摘　　要：以作者所在实验室前期构建的产嗜热脂肪芽孢杆菌β-环糊精葡萄糖基转移酶(β-CGTase)重组短小芽孢杆菌作为菌种,经过摇瓶发酵,得到酶活为49 U/mL的β-CGTase粗酶液。以马铃薯淀粉为底物用β-CGTase进行单酶法转化制备β-环糊精,并对转化条件进行优化。结果表明,最优反应条件为:反应时间18 h,初始pH 6.0,反应温度50℃,底物质量浓度15 g/dL,加酶量13 U/g底物。在最优条件下,总转化率最高为73.9%,其中β-环糊精比例为98.7%。在此基础上,建立了采用普鲁兰酶与β-CGTase复配同步转化淀粉制备β-环糊精的新工艺,并且优化了普鲁兰酶的加酶量。结果表明,当普鲁兰酶加量为50 U/g淀粉底物,反应时间18 h时,总转化率达到最高81.4%,其中β-环糊精占比97.7%。Previously,a recombinant Brevibacillus sp.producing the Bacillus stearothermophilus cyclodextrin glycosyltransferase was constructed.In this study,the strain was cultured in shake flask for 48 h,it showed that the highest extracellular enzyme activity was 49 U/mL.The supernatant of the medium was used as crude enzyme for the production ofβ-cyclodextrin.Then the reaction conditions,such as initial pH,reaction temperature,starch concentration,CGTase dosage,pullulanase dosage and reaction time,on the yields ofβ-cyclodextrin was investigated.The optimized conditions for the conversion as the following:the initial pH was 6.0,the reaction emperature was 50℃,initial starch concentration was 150 g/L,CGTase concentration was 13 U/mL,pullulanase concentration was 50 U/g starch.Under this conditions,the reaction was continued for 18 h,thecyclodextrin yield is 81.4%and the proportion ofβ-cyclodextrin is 97.7%.

关 键 词：β-环糊精葡萄糖基转移酶 Β-环糊精 酶转化 条件优化 同步转化 

分 类 号：Q814.9[生物学—生物工程]