Name the micro-organism which is used for the large scale production of alcohol.

Yeast, specifically the species Saccharomyces cerevisiae, is the microorganism used extensively for large-scale commercial alcohol production. This single-celled fungus carries out alcoholic fermentation, a metabolic process where it breaks down sugars (glucose, fructose, or sucrose) in the absence of oxygen, producing ethanol (alcohol) and carbon dioxide as byproducts. Breweries, distilleries, and wineries rely on controlled yeast fermentation to produce beer, wine, whiskey, vodka, rum, and other alcoholic beverages.

The alcohol industry carefully selects specific yeast strains and optimizes fermentation conditions—temperature, pH, sugar concentration, and oxygen levels—to maximize alcohol yield and develop desired flavors and aromas. Beyond beverage production, industrial-scale fermentation using yeast also produces bioethanol as a renewable fuel alternative to petroleum. The same species S. cerevisiae is also crucial in baking, where the carbon dioxide it produces causes bread dough to rise, though in baking the alcohol evaporates during cooking.