文献类型：期刊文献

英文题名：Heterologous expression and characterization of a novel thermo-halotolerant endoglucanase Cel5H from Dictyoglomus thermophilum

作者：Shi, Runrun[1];Li, Zhimin[1];Ye, Qin[1];Xu, Jianhe[1];Liu, Yan[2]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Michigan State Univ, E Lansing, MI 48824 USA

年份：2013

卷号：142

起止页码：338

外文期刊名：BIORESOURCE TECHNOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000322292800045)】；

基金：This study was supported by the National High Technology Research and Development Program of China (Grant No's. 2012AA022104 & 2012AA021205), The Fundamental Research Funds for the Central Universities, the Open Funding Project of the State Key Laboratory of Bioreactor Engineering, and Shanghai Leading Academic Discipline Project (No. B505). 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：Endoglucanase; Thermostability; Halo-tolerance; Cellulose binding module; Homology modeling

摘要：A novel beta-1,4-endoglucanase gene was cloned from Dictyoglomus thermophilum, designated as Cel5H for being a member of glycoside hydrolase family 5. The purified recombinant endoglucanase showed high hydrolytic activities on carboxylmethyl cellulose with a broad optimal temperature of 50-85 degrees C and an optimal pH of 5.0. Furthermore, this enzyme was highly thermostable with a half-life of 336 h at 70 degrees C and retained more than 80% of the initial activity after 135 days incubation at 50 degrees C. To enhance the performance of the thermophilic endoglucanase, chimeric enzymes containing Cel5H and syncretic cellulose binding module (CBM) were constructed. The results showed that all the CBMs were effective. In addition, Cel5H was highly tolerant against high salt concentration and distinguished from salt-tolerant bacteria since it was independent of high salt concentration. Three-dimensional structure of Cel5H was developed by homology modeling methods and surface electrostatic analysis was performed. (C) 2013 Elsevier Ltd. All rights reserved.