Domesticated Strains

S.cerevisiae is the principal yeast utilized in biotechnology worldwide, due largely to its unique key roles in many food fermentations and other industrial processes. Despite the tremendous importance of S.cerevisiae, relatively little is known about its origins. Industrial “domesticated” strains generally differ from laboratory strains, as well as from “wild” strains, in genetic and physiological properties. Several scientists, carried out research to study the origins and ecology of yeasts, and concluded that industrial S.cerevisiae strains used in industrial processes have primarily evolved within the industrial environment. While laboratory strains of S.cerevisiae can be grown stably under haploid or diploid states, industrial strains are usually polyploid and often sporulate poorly. This creates difficulties in performing classic and other genetic manipulations. Laboratory strains also differ from industrial strains in several phenotypic responses to environmental changes, nutrient restrictions, dehydration and cold stresses. Industrial strains of S.cerevisiae express phenotypes important in commercial processes, such as rapid and complete sugar fermentation, increased alcohol production and tolerance, formation of desired flavors and aromas, enhanced flocculation, ability to utilize disaccharides, low foaming tendency, and other characteristics.  The diversity of commercial S. cerevisiae strains likely represent adaptations within industrial environments, such as breweries, wineries, and bakeries.