Identification, Cloning and Characterization of Dictyoglomus Turgidum CelA, an Endoglucanase with Cellulase and Mannanase Activity  

作　　者：Phillip J. Brumm Spencer Hermanson Joshua Luedtke David A. Mead 

机构地区：[1]C5-6 Technologies, 2120 W. Greenview Drive, Middleton, W153562, USA

出　　处：《Journal of Life Sciences》2011年第7期488-496,共9页生命科学（英文版）

摘　　要：The discovery of new, highly active, biomass-degrading enzymes is important to the development of a sustainable biofuels industry. Dictyoglomus turgidum, a thermophilic, anaerobic eubacterium that ferments cellulose and produces ethanol and hydrogen, was chosen as a candidate to screen for novel enzymes. A novel thermostable endoglucanase, CelA, was identified and purified during screening of a shotgun library of Dic（yoglomus turgidum and subsequently subcloned and expressed in E. coli. The celA gene coding for a 312 amino acid protein showed low homology to proteins outside the genus Dictoglomi and lacked an apparent signal peptide. CelA had a broad substrate range, possessing both endo and exo activity on soluble and insoluble β-（1,4）-Iinked glucose-containing substrates as well as endo activity on soluble and insoluble β-（1,4）-linked mannose containing substrates. The specific activity of CelA was 226 U/rag using β-glucan, 66 U/mg using glucomannan, and 63 U/mg using CMC as substrates. The high temperature optimum of 70 ℃ to 80 ℃ and wide substrate range of the enzyme might make it an excellent tool for biomass degradation at high temperature.

关 键 词：CELLULASE MANNANASE THERMOPHILIC biomass degradation Dictyoglomus turgidum. 

分 类 号：Q785[生物学—分子生物学] TS261.11[轻工技术与工程—发酵工程]