Heterologous expression of cellulases from Myceliophthora heterotalica F.2.1.4 in Pichia pastoris with characterization and purification of the enzymes produced

Abstract

The lignocellulosic material, found mainly in agro-industrial waste, is one of the most abundant natural organic complexes in the plant biomass, which is mainly composed of three main constituents: cellulose, hemicellulose and lignin. Cellulose is the biopolymer most commonly found in the vegetable kingdom, featuring a linear homopolymer composed of D-glucose residues joined by connection type ²-1.4 and can be used for bioethanol production by enzymatic hydrolysis. The cellulase enzyme complex is able to hydrolyze cellulose into fermentable monomers and it is naturally secreted by several filamentous fungi. Although several times this enzymes are detected in the growth medium for filamentous fungi, these enzymes with interesting properties may be impracticable for industrial due to low expression. From the biotecnologiacal standview, heterologous expression in Pichia pastoris provides many advantages for the production of recombinant eukaryotic proteins, producing enzyme types unique, without the interference of other enzymes in addition to being able to obtain high expression of the same, especially on an industrial scale . Recent studies have shown that the thermophilic fungus M. heterotalica F.2.1.4 is capable of producing cellulases with interesting properties for application in saccharification of sugarcane bagasse, but without a significant expression. Thus, this project aims to identify the gene coding for an endoglucanase and its cloning and expression in yeast Pichia pastoris. We also intend to purify and characterize the native and heterologous enzymes.