The effects of thermal and ethanolic stress in industrial strains of Saccharomyces cerevisiae

Abstract

Saccharomyces cerevisiae is exceptional microorganisms used in biotechnological processes, mainly in the ethanol production chain. Studies of the cellular responses of industrial yeasts under ethanolic and thermal stress in an association are still incipient. This study aimed to evaluate the action of thermal and ethanolic stress in industrial strains of Saccharomyces cerevisiae under different temperatures and concentrations of ethanol, to understand whether these factors influence ethanol production. For cytotoxicity and genotoxicity tests, yeasts were grown in 2% YPD medium incubated for 10 hours at 250 rpm. After growth, the samples were grown in sugarcane juice in concentrations of 5, 10 and 15% ethanol and incubated at 30 and 40 ºC. In Petri dishes containing the solid medium YPD 2% the yeasts were dripped and incubated for 72 hours the cytotoxic action was analyzed by cell growth and genotoxicity through the comet assay and ethanol production by gas chromatography. Cell growth occurred in all conditions, however, at 30 ºC there was inhibition in 10% (v v-1) of ethanol being potentiated in 15% (v v-1), at 40 ºC. The genotoxicity analysis showed an induction of DNA damage in yeasts, however, the FLE yeast was the one with the highest DNA damage index. The yeast Pedra-2 was more tolerant and produced more ethanol, showing to be a tolerant strain concerning the analyzed fermentative interferents.

Effect of temperature on the biological parameters of pink bollworm, Pectinophora gossypiella Saunders (Lepidoptera: Gelechiidae)

“…whereas, a study on S. frugiperda reported that, the persistent effect can be observed up to F 2 generation 36 . Cell damage was evident when Saccharomyces cerevisiae was exposed to higher temperature, resulting reduction in ethanol production 41 . Therefore, insects can alleviate the thermal stress and steadily recover over generations by compromising some developmental traits 39 .…”

Deletion of QDR genes in a bioethanol-producing yeast strain reduces propagation of contaminating lactic acid bacteria

“…Molecular Physiology of the Cell, Université Libre de Bruxelles (ULB), Biopark, Gosselies, Belgium. 2 Syngulon, Seraing, Belgium. 3 BRALim (Brewing and Food Sciences), LABIRIS, Brussels, Belgium.…”

“…Bioethanol is the biofuel most used worldwide in the transportation sector, its production having increased regularly since the early nineties 1 . In 2020, the USA and Brazil accounted, respectively, for 53% and 30% of global biofuel production 2 . Bioethanol is produced from a wide variety of renewable resources (feedstocks), and the yeast Saccharomyces cerevisiae is by far the microorganism most frequently used to carry out the biological process exploited in industrial-scale ethanol production, thanks to its unmatched ethanol yield (> 90%), productivity (> 1 g.L −1 .h −1 ), and tolerance (> 40 g.L −1 ) and its ability to ferment a wide range of sugars 1 .…”

Analysis of the fermentative profile of yeasts isolated from natural sources

“…For Cruz et al (2015), different temperatures distinctly affect the metabolic activity and growth of yeast, thus constituting one of the factors that can interfere in the fermentation process, as they present their metabolic efficiency between 25 °C and 30 °C (Sousa & Monteiro, 2012). Studies developed by Mueller et al (2020) comparing the physiological response of Fleischmann®, Pedra-2 and FT858 yeasts in fermentation medium containing different concentrations of ethanol (5, 10 and 15%) and at temperatures of 30 °C and 40 °C. They observed that the higher temperature interfered with the growth of yeast colonies and that, when associated with a higher concentration of ethanol, this inhibition was more effective and that the synergism of stress factors can lead to cell death.…”