Saccharomyces cerevisiae
Overview
Saccharomyces cerevisiae, commonly known as baker's yeast or brewer's yeast, is a species of yeast that has been instrumental in winemaking, baking, and brewing since ancient times. It is a unicellular eukaryotic organism in the fungi kingdom and is one of the most thoroughly researched eukaryotic model organisms in molecular and cell biology.
Taxonomy and Phylogeny
Saccharomyces cerevisiae is a member of the Saccharomycetaceae family in the Saccharomycetales order. It belongs to the Saccharomyces genus, which comprises several species of yeast. The genus name "Saccharomyces" derives from Greek words meaning 'sugar fungus'. The species name "cerevisiae" comes from Latin and means 'of beer'.
Morphology
Saccharomyces cerevisiae cells are round to ovoid, measuring 5-10 micrometers in diameter. They reproduce by a process known as budding, where a smaller daughter cell is formed on the parent cell. The bud then enlarges until it is the same size as the parent cell, at which point it separates.
Metabolism
Saccharomyces cerevisiae is a facultative anaerobe, meaning it can grow in the presence or absence of oxygen. In the presence of oxygen, it undergoes aerobic respiration, producing carbon dioxide and water as byproducts. In the absence of oxygen, it undergoes fermentation, producing carbon dioxide and ethanol.
Genetic Properties
The genome of Saccharomyces cerevisiae was the first eukaryotic genome to be completely sequenced. It consists of about 12 million base pairs, which encode approximately 6,000 genes. Most of these genes are located on 16 different chromosomes.
Applications
Saccharomyces cerevisiae has been used for thousands of years in the production of food and beverages. Today, it is also used in biotechnology for the production of ethanol, pharmaceuticals, and other chemicals. It is also a popular model organism in biological research, particularly in genetics and cell biology.