Identification and characterization of novel sugar transporters potentially involved in lignocellulosic biomass degradation process in Trichoderma reesei

Author(s)

Karoline Maria Vieira Nogueira

• Document type: Doctoral Thesis
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC)
• Defense date: 2019-05-31

Examining board members

Roberto do Nascimento Silva; Maria Helena de Souza Goldman; Richard John Ward

• Advisor: Roberto do Nascimento Silva

Abstract

The fungus Trichoderma reesei presents a surprising capacity to produce and secrete cellulases and hemicellulases, being the most important industrial fungus in the production of these enzymes that are used, among other purposes, in the industry of biofuels, such as bioethanol. During the natural process of degradation of lignocellulosic biomass, the fungus employs several sugar transporters with different affinities to a substrate. The identification and characterization of these sugar transporters can generate insights into the role of these components in the sugar transport system and the molecular mechanisms in which these proteins are involved in the cell. This work aims at the identification and characterization of new sugar transporters potentially involved in the degradation of biomass. For this, different tools were employed. In Chapter I, the characterization of a sugar transporter, Tr69957, previously identified by our research group through in silico RNA-seq data analysis, is described. Gene deletion of Tr69957 in T. reesei and functional ex vivo analyzes, through S. cerevisiae EBY.VW4000 strain complemented with candidate sugar transporter gene, suggests the role of this transporter in mannose, cellobiose and xylose uptake. In addition, transporter deletion affected the expression profile of cellulases encoding genes in T. reesei. In chapter II, a review containing research results from our group: Laboratory of Molecular Biotechnology presents the main data on the involvement of sugar transporters during the process of degradation of lignocellulosic biomass. Finally, in chapter III, through proteomic analyzes, 14 sugar transporters were identified during the growth of T. reesei in microcrystalline cellulose and glycerol. The identification of these sugar transporters in presence of cellulose demonstrates potential biological function during the degradation process. (AU)

• FAPESP's process: 15/09553-8 - Characterization of new sugar transporters involved in the regulation of lignocellulosic biomass degradation in Trichoderma reesei
• Grantee: Karoline Maria Vieira Nogueira
• Support Opportunities: Scholarships in Brazil - Doctorate