Análise poligênica de leveduras isoladas de destilaria de cachaça para fermentação de alta eficiência

Abstract

Ethanol is a product of high economic importance, taking part of different industrial sectors such as pharmaceuticals, fuels and beverages. The origin of ethanol, which is the fermentation of must rich in sugarsby Saccharomyces cerevisiae yeastis always the same regardless of application. The ethanol production from sugar cane is the most efficient available, but new (bio) technologies can be applied to improve the process. The high gravity fermentation allowshigher ethanol production in batch, reducing waste production and, therefore,resulting in less overall costs. Some approaches like genetic mapping of QTL (Quantitative Trait Loci) have wide application and they have shown regions involved in a series of complex phenotypes of interest, such as resistance and ethanol production. Given the small amount of information related to industrial yeasts, especially in Brazil, this study was conducted in order to test and select strains for fermentation in high-gravity as well asto map regions (QTL) in the Saccharomyces cerevisiae genome associated to thephenotype of maximum ethanol accumulation. Among four yeast strains from cachaça production, the UFLACA798 strain was chosen as the best fermenter in high gravity conditions. After crossing this (UFLA798) with the S288c strain, 196 F1 segregants were tested in liquid fermentation and 29 segregantspresenting a similar parental behavior were selected for sequencing and mapping of QTL. The results indicated genes present in chromosomes II, V and VII possibly associated with the phenotype of interest. Furtherin vivoanalysis are required to confirm the relationship of putative genes with the phenotype under study.