sucrosefermenting

Sucrosefermenting describes the ability of certain microorganisms to ferment sucrose, a disaccharide of glucose and fructose, as a carbon source. In many sucrose-fermenting organisms, sucrose is first broken down by sucrase or invertase outside or inside the cell, yielding glucose and fructose that are then metabolized through glycolysis under anaerobic conditions to produce fermentation end products such as ethanol and carbon dioxide, along with smaller amounts of other compounds. The exact products depend on the organism and environmental conditions; some microbes produce lactic acid, acetic acid, or a mix of acids and alcohols instead of ethanol.

Biochemically, sucrose fermentation begins with hydrolysis of the sugar, enabling uptake of glucose and fructose. In Saccharomyces cerevisiae and many other yeasts, the main outcome is ethanol and CO2, with ATP generated by substrate-level phosphorylation during glycolysis. In lactic acid bacteria, the monosaccharides may be fermented to lactic acid, often with limited production of other byproducts. Some microorganisms, such as Zymomonas mobilis, utilize efficient pathways that favor ethanol production from the resulting sugars.

Organisms commonly described as sucrosefermenting include Saccharomyces species (brewing and baking yeasts), certain lactic acid bacteria, and some aerobic or facultatively anaerobic bacteria capable of hydrolyzing sucrose and fermenting the resulting monosaccharides. In industry, sucrose fermentation is exploited in bread making, wine and beer fermentation, and the production of ethanol from sucrose-rich feedstocks like sugarcane molasses or sugar beets.

Factors affecting sucrose fermentation include pH, temperature, oxygen availability, and sugar concentration, as well as the presence of inhibitors or competing microbes. Fermentation performance is often assessed by gas production or acid formation in standard sugar fermentation tests.