Why, when, and how did yeast evolve alcoholic fermentation?

Abstract

The origin of modern fruits brought to microbial communities an abundant source of rich food based on simple sugars. Yeasts, especially Saccharomyces cerevisiae, usually become the predominant group in these niches. One of the most prominent and unique features and likely a winning trait of these yeasts is their ability to rapidly convert sugars to ethanol at both anaerobic and aerobic conditions. Why, when, and how did yeasts remodel their carbon metabolism to be able to accumulate ethanol under aerobic conditions and at the expense of decreasing biomass production? We hereby review the recent data on the carbon metabolism in Saccharomycetaceae species and attempt to reconstruct the ancient environment, which could promote the evolution of alcoholic fermentation. We speculate that the first step toward the so-called fermentative lifestyle was the exploration of anaerobic niches resulting in an increased metabolic capacity to degrade sugar to ethanol. The strengthened glycolytic flow had in parallel a beneficial effect on the microbial competition outcome and later evolved as a “new” tool promoting the yeast competition ability under aerobic conditions. The basic aerobic alcoholic fermentation ability was subsequently “upgraded” in several lineages by evolving additional regulatory steps, such as glucose repression in the S. cerevisiae clade, to achieve a more precise metabolic control.

Effects of Oxygen Availability on Acetic Acid Tolerance and Intracellular pH in Dekkera bruxellensis

“…The yeast Saccharomyces cerevisiae exhibits a strong fermentative lifestyle due to the Crabtree effect and to its ability to grow at a high rate even under anaerobic conditions (1-3) and low pH (4). In the context of natural evolution, this ability may have helped this organism to consume sugars quickly and to compete with other microorganisms by producing ethanol (5,6). During yeast evolution, this particular strategy apparently evolved in at least two lineages: the Saccharomyces complex and Dekkera/Brettanomyces (7).…”

Microbial and Chemical Diversity of Traditional Non-Cereal Based Alcoholic Beverages of Sub-Saharan Africa

“…Common consortia harbor yeasts, acetic acid, and lactic acid bacteria [34]. The diversity in carbon metabolism pathways among the different microbes in the consortia, allows mixed culture fermentation towards the production of different primary and secondary metabolites that influence the overall aromatic complexity of the alcoholic beverage [65][66][67]. Such mixed culture fermentation has become common in the wine and beer industries in an effort to improve the distinctive flavors of the alcoholic beverages.…”

Signaling pathways and posttranslational modifications of tau in Alzheimer's disease: the humanization of yeast cells

“…However, it should be noted that respiratory activity is diminished by glucose-repression in the fermentation-oriented yeast S. cerevisiae, and mitochondria are also less abundant under such conditions. In fact, S. cerevisiae has been selected for thousands of years for its capacity for alcoholic fermentation [90] and with respect to energy production is hardly a physiological equivalent of neurons, which rely on their respiratory metabolism [91].…”