Biochemical and structural characterization of the novel auxiliary enzymes identified by a metasecretomic approach

Abstract

Plant cell-wall deconstruction is one of the main challenges to be overcome in order to turn cellulosic ethanol into a reality. Plant biomass is a highly complex heterogeneous composite material and the access of enzymes to their specific polysaccharide substrates is limited by the recalcitrance and chemical complexity of the cell wall. The lytic polysaccharide monooxygenases (LPMO) are a promising new class of enzymes, which could help to alleviate this problem. These copper-dependent enzymes were discovered just a few years ago, and were shown to play an important role in the process of biomass degradation, causing selective oxidation of the chemical bonds of the complex plant cell wall polysaccharides, and thus boosting performance of enzymatic cocktails. An ongoing meta-omics project (FAPESP-RCUK Project 2010/52362-5) which is being conducted in collaboration with the University of York (United Kingdom) allowed us to discover many different CAZy enzymes from microbial communities that survive on rotting sugar bagasse and cereal straw, including potential unique LPMO's from the CAZy family's AA10 and AA11. As a next step and in collaboration with the Neil Bruce´s group form the Biology Department of the University of York, we propose to proceed with the production, and the biochemical and structural characterization of the LPMO's and other auxiliary enzymes, and to explore their potentials in the field of biotechnology. Our collaboration will allow us to make a rapid progress in this vibrant field and make an effective use of the outputs of the abovementioned FAPESP-RCUK project. (AU)