A new thermostable ¦Â-glucosidase mined from Dictyoglomus thermophilum: Properties and performance in octyl glucoside synthesis at high temperatures
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- 作者：Zheng-Zheng Zou ; Hui-Lei Yu ; Chun-Xiu Li ; Xin-Wen Zhou ; Chihiro Hayashi ; Jie Sun ; Bao-Hong Liu ; Tadeyuki Imanaka ; Jian-He Xu
- 关键词：¦Â-Glucosidase ; Dictyoglomus thermophilum ; Thermostability ; Octyl glucoside ; Reverse hydrolysis
- 刊名：Bioresource Technology
- 出版年：2012
- 出版时间：August, 2012
- 年：2012
- 卷：118
- 期：Complete
- 页码：425-430
- 全文大小：319 K
文摘
A new ¦Â-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 ¡ãC, respectively. Therefore it was used for direct glycosylation of n-octanol at 70 ¡ãC instead of 50 ¡ãC 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 ¡ãC 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.