Use of (meta) genomics and microbial consortia for the creation of enzymatic cocktail for the production of metabolites of industrial interest through the lignocellulosic biomass biorefinery

Abstract

The microbiota is an abundant source of genes for industrial application. In forty years of work, we have assembled a collection of diverse genomes, metagenomas and consortia. Among these data, we have metagenomas from forest soils, sugarcane and eucalyptus cultivation soils, rumen, filter cake, and ecosystems in different stages of recovery from mining activity (Sabará, MG); sequenced genomes such as those of the bacteria Chitinophaga sp. CB10, Mesorhizobium sp. J5 and Thermomonospora sp. CIT 1; in addition to bacterial pools of soils contaminated with diesel oil and sugarcane cultivation. The latter is able to develop effectively in a culture medium containing only sugarcane bagasse as a carbon source, causing significant decreases in the contents of cellulose, hemicellulose and lignin, as well as partial disruption of the planar and compact microstructure of the bagasse, with the presence of cracks and flaking after five days of cultivation, which can be useful as a form of pre-treatment of biomass. In view of this, we propose studies aimed at the production of enzymatic cocktails to obtain biotechnological products such as fermentable sugars and rare sugars such as tagatose and xylitol, and phenolic derivatives from lignocellulose. Under this approach, an initial cocktail of three enzymes capable of depolymerizing bagasse will be used as a starting point for the optimization of these processes of interest through combination with different enzymes and engineering of cavity and active site architecture. This pre-cocktail contains a potentially progressive endoglucanase from CB10, and a wide temperature spectrum acid laccase and a beta-glucosidase stimulated by its product (glucose) and tolerant to ethanol (both from eucalyptus soil metagenome). Allied to this, we propose the characterization of the metabolic network of the sugarcane soil consortium, contributing to the identification of biotechnological biomass refinery pathways. (AU)