Thermobifida fusca麦芽三糖淀粉酶的重组表达及其在麦芽三糖制备中的应用  

Recombinant expression of maltotriose-forming alpha-amylases from Thermobifida fusca and its application in preparation of maltotriose

作　　者：胡凡 宿玲恰[1,2] 吴敬 HU Fan;SU Lingqia;WU Jing(State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi 214122,China;Key Laboratory of Industrial Biotechnology Ministry of Education,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]工业生物技术教育部重点实验室(江南大学),江苏无锡214122

出　　处：《食品与发酵工业》2020年第5期23-30,共8页Food and Fermentation Industries

基　　金：国家自然科学基金(31730067);江苏省自然科学基金(BK20180082)。

摘　　要：麦芽三糖淀粉酶以淀粉或麦芽糊精为原料,可生产麦芽三糖,在食品、饮料等行业具有广泛的应用前景。实验将Thermobifida fusca NTU22来源的麦芽三糖淀粉酶在枯草芽孢杆菌WS11中进行重组表达,并进行酶学性质分析,重组酶的最适温度和pH分别是55℃和6.0。在此基础上探究了重组酶作用于麦芽糊精生产麦芽三糖的最佳条件。结果表明,以15%浓度的麦芽糊精(DE 5-7)作为底物时,酶转化的最佳条件是温度55℃、pH 5.5、加酶量60 U/g(底物)、普鲁兰酶加酶量32 U/g(底物)、反应时间11 h,此时得到麦芽三糖转化率44.4%。该研究为工业制备麦芽三糖提供了理论依据。The maltotriose-formingα-amylase(AmyA)can produce maltotriose-rich syrup from starch or maltodextrin,and has broad application prospects in food and beverage industry.The maltotriose-formingα-amylase derived from Thermobifida fusca NTU22(referred as TfAmyA)was recombinantly expressed in Bacillus subtilis WS11 for the first time.The recombinant TfAmyA was further purified and characterized.The optimal temperature of the TfAmyA is 55℃,the optimal pH is 6.0.The optimal conditions for maltotriose production from maltodextrin catalyzed by the recombinant TfAmyA were also investigated.The results showed that when 15%(mass concentration)maltodextrin(DE 5-7)was used as the substrate,the optimal conditions for enzymatic conversion were temperature 55℃and pH 5.5.The dosage of TfAmyA is 60 U/g substrate,and the dosage of pullulanase was 32 U/g substrate.Under these conditions,the maximum conversion rate of maltotriose was 44.4%when the reaction proceeded to 11 h.These results indicated that the recombinant TfAmyA has superior properties and provides a theoretical basis for the industrial preparation of maltotriose.

关 键 词：麦芽三糖淀粉酶 Thermobifida fusca 枯草芽孢杆菌 麦芽糊精 麦芽三糖 

分 类 号：TS201.2[轻工技术与工程—食品科学]