earticle

영어

A metagenomic approach is an efficient way for discovery of novel and useful genes from uncultured environmental microorganisms. In this study, we constructed metagenomic libraries from cow rumen fluids. Screenings of the libraries revealed a clone showing carboxymethyl
cellulolytic activity. Further analysis of the insert DNA showed an ORF encoding cellulase. A multiple sequence analysis with the deduced amino acid sequences of engR1 showed the highest identity with endoglycosidase from uncultured bacterium (62%) followed by beta-1,4-endoglucanase from Prevotella bryantii (49%). The recombinant EngR1 protein was not only highly active against soluble cellulose containing β-1,4 linkages, such as barley β-glucan but also active against hemicellulose such as xylan. The highest enzymatic activity was observed at pH 4.0 and 43℃with recombinant EngR1. The enzyme was highly stable at 50℃ for 120 min.