Construction of a S. cerevisiae strain, by the CRISPR/Cas9 system, capable of expressing an LPMO, aiming at the improvement of the saccharification of lignocellulosic biomasses

Abstract

The environmental impacts resulting from the release of greenhouse gases have stimulated many efforts to replacing fossil fuels with biofuels. In this sense, renewable lignocellulosic biomasses are an excellent alternative, since they consist of cellulose and hemicellulose, which after hydrolysis by CAZymes (Carbohydrate-Active Enzymes) can be converted into fermentable sugars, which is one of the biggest bottlenecks in the production of biofuels. Thus, searching for new enzymes capable of increasing efficiency and lowering costs of hydrolysis processes has been the target of many researchers. In this scenario, transcriptome and secretome analysis of the fungus A. fumigatus grown in the presence of sugarcane bagasse (SEB), carried out in our laboratory (2014/10466-0), revealed the production of important enzymes, among them the Lytic Polysaccharide Monooxygenase (LPMOs). The LPMOs have a mechanism of oxidoreduction under polysaccharide matrix crystalline regions favoring the action of enzymes such as GHs. Thus, the objectives of this project are the overexpression of an A. fumigatus LPMO in S. cerevisiae strain by the CRISPR/Cas9 technique, aiming at amore efficient saccharification process of the cellulose besides allowing the better characterization of LPMOs activity during the supplementation of commercially available enzymatic cocktails. The results of this project will help the objectives proposed by the project under development in our laboratory (Projeto Fapesp: 2016/190950). (AU)