Genomic and transcriptomic analysis in Saccharomyces cerevisiae yeasts strains isolated from ethanol, wine and beer production for industrial applications

Abstract

The fermentation industry pursues alternatives to improve the process and bring fermentation products with special or unique characteristics. The discovery and improvement of new yeast strains able to develop a desirable and controllable phenotype is a puzzling factor. Since 2009, the Biochemistry and Applied Genetics Laboratory - LBGA-UFSCar has been isolating strains from Brazilian bio-ethanol production process, resulting in a yeast collection that currently has approximately 600 promising strains both in ethanol as in beer production. For example, the isolate LBGA-287 shows increased maltose consumption, growth and fermentation rates compared to commercial yeast SafBrew T-58 was used to brew a blond ale, of which the flavour composition and drinkability were approved by sensorial panels consisting of both trained beer sommeliers and non-specialized consumers. Further, the library holds a thermotolerant strain (LBGA-01) that has excellent characteristics for the production of ethanol due its robustness and that has been licensed for industrial application. This yeast could be used to provide several benefits for traditional bioethanol production and also for simultaneous saccharification and fermentation (SSF) of starch or lignocellulosic biomass. In the here presented research we will aim in identify other new promissor strains with desirable phenotypes for industry applications as example strains with (I) the production of different aromas; (II) consumption of different Carbon and Nirogen sorces; (III) fermentation in high temperatures, ethanol and sugar concentration among others. Using a combination of omics techniques, i.e. genomics, transcriptomics, complemented by phenomics, we aim to better understand the genetic signals that lead to these different phenotypic characteristics. The comparison will be done with commercial reference strains for beer and/or ethanol production in pilot scale fermentation experiments. The phenotyping will be performed in collaboration with the Prof. Dr. Sam Crauwels from Katholieke Universiteit Leuven, Belgium, who has ample expertise with phenotyping and in specific with Biolog Phenotype Microarray technology. Further, as a member of the Leuven Institute for Beer Research, PME&BIM has access to the center for Aroma & Flavour Technology (Campus Ghent, KU Leuven) that performs analytical and sensory measurements of beer and fermentation products using state-of-the-art Technologies not available in Brazil. The resulting findings could lead to the identification of genome alterations that could be used in the transformation of industrial yeasts using molecular tools as CRISPR-Cas9 technology for different purposes in bio-ethanol production and brewing. (AU)