Yeast
Yeast is a group of unicellular fungi, with about 1,500 recognized species.
Yeast is a group of unicellular fungi, with about 1,500 recognized species. Most yeasts belong to the phylum Ascomycota, while a smaller number are Basidiomycota. They are found worldwide and are important in food production, biotechnology, and some diseases.
Classification and biology
Yeast is a broad term for fungi that grow primarily as single cells. They reproduce mainly by budding, though some reproduce by fission, and they are distributed across the Ascomycota and Basidiomycota lineages.
Ecology
Yeasts occur worldwide in soils and on plant surfaces and are especially common in sugary habitats such as fruits and flower nectar. They often act as decomposers and nutrient recyclers in ecosystems.
Human use
People have used yeast for centuries in food and beverage fermentation. Saccharomyces cerevisiae is the main species used for bread, beer, and wine production, and it is also important in biotechnology and research.
Medical relevance
Some yeasts are opportunistic or pathogenic, including Candida albicans, and certain yeast-like fungi can cause infections in humans and animals. These organisms are medically important because they can affect immunocompromised people as well as others.
Key facts
- Yeasts are single-celled fungi and are eukaryotic microorganisms.
- Most known yeast species are classified in Ascomycota, with fewer in Basidiomycota.
- Yeasts are widespread in nature, including soil, plant surfaces, fruits, and flower nectar.
- Selected strains of Saccharomyces cerevisiae are widely used in baking, brewing, and winemaking.
- Some yeasts can cause disease in humans and other animals, including Candida, Histoplasma, and Blastomyces.
Yeast is relevant to Canadian readers through baking, brewing, winemaking, food science, and microbiology research, all of which are active sectors in Canada.
Frequently asked questions
What is yeast?
How many yeast species are there?
What are the main types of yeast?
What is Saccharomyces cerevisiae?
Why is yeast important in food production?
Can yeast cause disease?
References
- Britannica — https://www.britannica.com/science/yeast-fungusSupports: Yeast as unicellular fungi; approximate species count; major phyla; ecological distribution; uses; pathogenic species.
- The Canadian Encyclopedia — https://thecanadianencyclopedia.ca/en/article/yeastSupports: Yeast as unicellular fungi; classification; budding and fission; Canadian-reader context.
- Saccharomyces Genome Database — https://wiki.yeastgenome.org/index.php/What_are_yeast%3FSupports: Yeast as single-celled fungi; phylum-level diversity; eukaryotic nature.
- Wikipedia — https://en.wikipedia.org/wiki/YeastSupports: General overview of yeast diversity and reproduction; used cautiously alongside authoritative sources.
- Britannica — https://www.britannica.com/science/Saccharomyces-cerevisiaeSupports: Saccharomyces cerevisiae as baker's/brewer's yeast and its uses in food production and research.