Molecular Characterization of Dominant Yeast Strains Isolated During Ethanol Fermentation Process

Genotypic and phenotypic characterization of industrial autochthonous Saccharomyces cerevisiae for the selection of well-adapted bioethanol-producing strains

“…A similar situation has been reported in fuel bioethanol plants in Brazil where baker's yeast and two other S. cerevisiae strains used traditionally as starters, were unable to compete with wild contaminating yeasts (Basso et al, 1993). Consequently, the original starter yeasts were completely replaced by other highly productive yeast strains (Basso et al, 2008;Viana et al, 2020) that dominate the fermentation tank, allowing efficient and stable fermentations (Basso et al, 2008;Lopes et al, 2016). In those studies it was observed that wild strains previously isolated from distilleries were capable to survive the recycling when reintroduced in industrial fermentation processes (Lopes et al, 2016).…”

“…Due to the great yeast biodiversity found in distillery environments, exploring the natural biodiversity of S. cerevisiae strains could be an interesting route to improve the understanding of the challenges faced by yeast cells during bioethanol fermentation and also to find strains with a better performance that may be used in industrial bioethanol production. Molecular techniques such as karyotyping by Pulsed-field gel electrophoresis (PFGE) (Basso et al, 2008;Andrietta et al, 2017), Restriction Fragment Length Polymorphism of mitochondrial DNA (mtDNA-RFLP) (Lopes et al, 2019), and PCR-fingerprinting have successfully been used to monitor S. cerevisiae yeast population dynamic throughout ethanol industrial fermentation (Bas ílico et al, 2008;Pajares et al, 2009;Carvalho-Netto et al, 2013;Viana et al, 2020). Moreover, DNA fingerprinting based on the polymorphism analysis of microsatellite loci (or Simple Sequence Repeat markers, SSR) is capable of discriminating and comparing very closely related strains and is therefore a powerful tool to study population genetics over a lower number of generations (Ayoub et al, 2006;Jubany et al, 2008).…”