QTL mapping related to fermentative robustness of a Brazilian industrial strain of Saccharomyces cerevisiae in corn ethanol production

Abstract

In the perspective of the current need to restructure the Brazilian energy matrix, the use of corn as a raw material for fuel production has advanced exponentially in the country. This scenario is mainly motivated by the possibility of operating in the off-season of sugarcane and by taking advantage of the surplus of this grain. Therefore, to achieve the demands of this biofuel in the coming years, the development of specialized yeasts for the fermentation process of corn ethanol is configured as an area of great commercial interest. Thus, the study of the genetic architecture related to the phenotypes of response to this industrial process, especially for a saccharification and simultaneous fermentation (SSF) operation, becomes essential. A Quantitative Trait Loci (QTL) mapping associated with robustness against starch SSF and the high concentration of maltose present at the beginning of fermentation will be performed with the Brazilian industrial yeast BG-1, native to the first-generation sugarcane process and recently identified as capable of improving corn ethanol yields. For this, selection of superior strains will be achieved from the screening of segregants and QTL mapping will be done using a bulk analysis approach of the segregants, from a population of yeasts selected in both stresses described above. After identifying candidate QTLs, the mutations will be validated using reciprocal hemizygosity analysis. In addition to the identification of alleles that contribute to traits of biotechnological interest, the present proposal will enable the development of new advanced strains, contributing to the consolidation of the Brazilian corn ethanol industry.