文献类型：期刊文献

英文题名：A new thermostable β-glucosidase mined from Dictyoglomus thermophilum: Properties and performance in octyl glucoside synthesis at high temperatures

作者：Zou, Zheng-Zheng[1];Yu, Hui-Lei[1];Li, Chun-Xiu[1];Zhou, Xin-Wen[2,3];Hayashi, Chihiro[4];Sun, Jie[1];Liu, Bao-Hong[2,3];Imanaka, Tadeyuki[1,4];Xu, Jian-He[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Lab Biocatalysis & Synthet Biotechnol, Shanghai 200237, Peoples R China;[2]Fudan Univ, Dept Chem, Shanghai 200433, Peoples R China;[3]Fudan Univ, Inst Biomed Sci, Shanghai 200433, Peoples R China;[4]Ritsumeikan Univ, Coll Life Sci, Dept Biotechnol, Shiga 5258577, Japan

年份：2012

卷号：118

起止页码：425

外文期刊名：BIORESOURCE TECHNOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000307259600057)】；

基金：This research was financially supported by National Natural Science Foundation of China (Grant Nos. 20736002, 20902023 & 31071604), Ministry of Science and Technology (No. 2009CB724706) and Fundamental Research Funds for the Central Universities from Ministry of Education, P.R. China (No. 20090074120014). The authors are grateful to professor Guo-Qiang Lin at Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, for his kind encouragement and careful discussion on this project. We cordially thank Dr. Xiao-Yan Zhang at East China University of Science and Technology for her contribution to cultivation of the microorganisms.

语种：英文

外文关键词：beta-Glucosidase; Dictyoglomus thermophilum; Thermostability; Octyl glucoside; Reverse hydrolysis

摘要：A new beta-glucosidase (DtGH) representing 40% identity with an apple seed glycosidase (ASG) was cloned from Dictyoglomus thermophilum. DtGH showed extremely high thermostability in aqueous solution, with half-lives of 533, 44, and 5 h measured at 70, 80 and 90 degrees C, respectively. Therefore it was used for direct glycosylation of n-octanol at 70 degrees C instead of 50 degrees C as usually. As a result, the glucose based conversion was increased by 27%, but the time spent to reach equilibrium was decreased from 7 d to 3 d. This enzyme also exhibited excellent stability under the reaction environment, retaining 70-80% of its initial activity after 7 d of incubation at 70 degrees C in either 1.7 M glucose solution or octanol-aqueous (85:15, v/v) system. It could retain part of synthetic activity even in boiling water. Owing to the strong glucose-tolerance and extremely high thermostability, DtGH should be promising for various glucosides synthesis. Crown Copyright (c) 2012 Published by Elsevier Ltd. All rights reserved.