Functional Metagenomic Technologies for the Discovery of Novel Enzymes for Biomass Degradation and Biofuel Production

As a long-term solution to fossil fuel depletion, deployment of renewable biofuel from plant biomass degradation would provide significant economic benefits and energy security. Degradation of recalcitrant plant biomass by microbial catalysis is one of the key challenges of biofuel production; thus, development of novel enzymes has become increasingly important. With recent advances in metagenomic technologies, such as new-generation sequencing, mining the metagenome for enzymes with value in biofuel synthesis is becoming more efficient. Here, we review current metagenomic technologies that have been used in novel enzyme discovery, and provide examples of enzymes obtained from metagenomic libraries (cellulases, lipases, esterases, proteases, laccases, pectinases, amylases, and feruloyl esterases). These are valuable for enzymatic conversion of lignocellulosic materials and other biomass feedstocks to biofuel.