7-02: Discovery of novel cellulases and hemicellulases from unique metagenomic libraries

Microorganisms encompass the largest resource of metabolic and genetic diversity encountered on Earth. Since a major part of the microbiota in natural ecosystems (often 95 - 99%) is not culturable, the target enzyme activity or DNA sequence will only be accessible via metagenomics-based tools. There is growing interest to discover more efficient enzymes for different applications. Especially the increasing use of lignocellulosic for fules and chemicals necessitates discovery and development of novel lignocellulolytic enzymes. We report the use of metagenomic techniques to screen for novel cellulase and hemicellulase activities. Metagenomic DNA was isolated from unique environmental samples and controlled composts enriched with various lignocelulosics. Fosmid and plasmid-based expression libraries were constructed and screened for cellulase activity based on dyed carboxymethyl cellulose (CMC) and Azurin-crosslinked xylan. Several interesting novel enzymes were discovered in the screen.