Heterologous expression, characterization and comparison of two endoglucanases from family GH45 obtained from the ascomycete Myceliophthora thermophila and the basidiomycete Gloeophyllum trabeum genomes

Abstract

The increase in global demand for fuels combined with the problems related to the emission of greenhouse gases into the atmosphere has put fuels in the spotlight, amongst them the second-generation ethanol, produced by alcoholic fermentation of carbohydrates obtained from the hydrolysis of vegetal biomass. Among the several ways that lignocellulosic biomass can be hydrolyzed to fermentable sugars the enzymatic hydrolysis shows up as the more viable option. However, this is a very complex and highly recalcitrant material, making its utilization in industrial scale a challenge. Thus, the study of new enzymes capable to hydrolyze this material in time and with costs that make its utilization in large scale possible is essential. Within this scenario, the enzymes GH45, endoglucanases able to act on the amorphous part of the cellulose, which are already used on the treatment of cotton fibers, show up as targets of study due to its differentiated mode of action. In this way, this projects propose to study the GH45 enzymes being one from the thermophilic fungus Myceliophthora thermophila and other from the basidiomycete Gloeophylum trabeum heterologously expressed in Aspergillus nidulans A773 and 1) determine the cultivation conditions that propitiate maximum expression of the enzyme; 2) characterize biochemically them regarding to pH, temperature and thermal stability. (AU)