Saccharomyces cerevisiae

Saccharomyces cerevisiae (ˌsɛrəˈvɪsi.iː) (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungus microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have been originally isolated from the skin of grapes. It is one of the most intensively studied eukaryotic model organisms in molecular and cell biology, much like Escherichia coli as the model bacterium. It is the microorganism behind the most common type of fermentation. S. cerevisiae cells are round to ovoid, 5–10 μm in diameter. It reproduces by budding. Many proteins important in human biology were first discovered by studying their homologs in yeast; these proteins include cell cycle proteins, signaling proteins, and protein-processing enzymes. S. cerevisiae is currently the only yeast cell known to have Berkeley bodies present, which are involved in particular secretory pathways. Antibodies against S. cerevisiae are found in 60–70% of patients with Crohn's disease and 10–15% of patients with ulcerative colitis, and may be useful as part of a panel of serological markers in differentiating between inflammatory bowel diseases (e.g. between ulcerative colitis and Crohn's disease), their localisation and severity. "Saccharomyces" derives from Latinized Greek and means "sugar-mould" or "sugar-fungus", saccharon (σάκχαρον) being the combining form "sugar" and myces (μύκης) being "fungus". cerevisiae comes from Latin and means "of beer". Other names for the organism are: Brewer's yeast, though other species are also used in brewing Ale yeast Top-fermenting yeast Baker's yeast Ragi yeast, in connection to making tapai Budding yeast This species is also the main source of nutritional yeast and yeast extract. In the 19th century, bread bakers obtained their yeast from beer brewers, and this led to sweet-fermented breads such as the Imperial "Kaisersemmel" roll, which in general lacked the sourness created by the acidification typical of Lactobacillus.