ABSTRACT

The term “fermentation” is derived from the Latin word fervere, which means “to boil.” Microbiologically, the term fermentation describes any process where microbial biomass is used for production of a product. However, from a biochemical point of view, it is an anaerobic energy-generating process where both the electron donor and acceptor are organic compounds, and neither oxygen nor any other inorganic compound acts as an electron acceptor (Stanbury 1988). Fermented foods and beverages have been produced since the Neolithic age without knowing the role of microorganisms in this process. In the mid-1600s, A.V. Leeuwenhoek (of The Netherlands) observed “animalcules” in a sample of fermented wine and beer (Fleet 1998).1 Nearly 200 years after Leeuwenhoek’s observation, in 1861, Louis Pasteur (of France) discovered that yeast is involved in fermentation, and it can convert sugar to ethanol and carbon dioxide. In 1883, Emil Christian Hansen from the Carlsberg brewery (in Denmark) rst isolated yeast and used it for the fermentation of beer (Fleet 1998; Dequin 2001). A few years later, in 1890, a pure culture of wine yeast was isolated by Müller-Thurgau from Geisenheim (Germany) (Dequin 2001). In continuation with these achievements, application of pure yeast cultures for alcoholic beverage fermentation has been considered. For industrial production of alcoholic beverages, application of selected yeast strains as inoculum has certain advantages. First, it can dominate the indigenous yeast or other fungus present in raw materials, which may otherwise be involved in spoilage or production of undesirable compounds. Second, selected yeast with high production efciency can be applied, and the nal product quality can be predicted. Further, using recent tools for molecular microbiology and genetic engineering, novel and more-efcient yeast strains have been developed. Successful commercial exploitation of such novel microbial systems and other recent technological developments in this eld have helped the global alcoholic beverage industry to grow rapidly. Presently, the global alcoholic beverage market is US$900 billion, and it is still growing with active participation of developing regions, such as China, India, and Russia.2