Saccharomyces cerevisiae is the most used species of yeast in commercial ethanol production. In which industrial context is it most commonly employed as a yeast species?

• A. Commercial ethanol production
• B. Commercial cheese production
• C. Commercial yogurt production
• D. Commercial beer production

Answer: (A)

Saccharomyces cerevisiae is favored in industrial fermentation because it efficiently converts sugars into ethanol and can tolerate the ethanol it produces, enabling high-volume, reliable production. These traits make it the workhorse for commercial ethanol production, where large-scale processes ferment feedstocks like molasses, corn starch, or sugarcane into ethanol under controlled anaerobic conditions. In dairy contexts, cheese and yogurt rely on bacteria (and specific cultures) rather than yeast for the primary fermentation, so this yeast is not central there. Beer production does use yeast as well, including this species in many strains, but the dominant industrial role of Saccharomyces cerevisiae in terms of scale and economic impact is in ethanol production.