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] State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China; [2] Biosystems and Agricultural Engineering, Michigan State University, East Lansing MI 48824, United States

年份：2013

卷号：142

起止页码：338

外文期刊名：Bioresource Technology

收录：EI(收录号：20132516430087)

语种：英文

外文关键词：Cloning

摘要：A novel β-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. °C and an optimal pH of 5.0. Furthermore, this enzyme was highly thermostable with a half-life of 336. h at 70. °C and retained more than 80% of the initial activity after 135. days incubation at 50. °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. ? 2013 Elsevier Ltd.