Yeast

yeastsbrewer's yeastbudding yeastyeast cellwild yeastbrewers yeastbrewing yeasttop-fermenting yeastyeast breadyeast cells
Yeasts are eukaryotic single-celled microorganisms classified as members of the fungus kingdom.wikipedia
1,776 Related Articles

Fungus

Fungifungalnecrotrophic
Yeasts are eukaryotic single-celled microorganisms classified as members of the fungus kingdom.
A fungus (plural: fungi or funguses ) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms.

Mold

mouldmoldsfilamentous fungi
Yeasts, with their single-celled growth habit, can be contrasted with molds, which grow hyphae.
In contrast, fungi that can adopt a single-celled growth habit are called yeasts.

Fermentation in food processing

fermentationfermentedferment
The yeast species Saccharomyces cerevisiae converts carbohydrates to carbon dioxide and alcohols a process known as fermentation.
Fermentation in food processing is the process of converting carbohydrates to alcohol or organic acids using microorganisms—yeasts or bacteria—under anaerobic conditions.

Ethanol

alcoholbioethanolethyl alcohol
The yeast species Saccharomyces cerevisiae converts carbohydrates to carbon dioxide and alcohols a process known as fermentation.
Ethanol is naturally produced by the fermentation of sugars by yeasts or via petrochemical processes, and is commonly consumed as a popular recreational drug.

Ascomycota

Ascomycetesascomycetesac fungi
The term "yeast" is often taken as a synonym for Saccharomyces cerevisiae, but the phylogenetic diversity of yeasts is shown by their placement in two separate phyla: the Ascomycota and the Basidiomycota.
Familiar examples of sac fungi include morels, truffles, brewer's yeast and baker's yeast, dead man's fingers, and cup fungi.

Dimorphic fungus

dimorphic fungidimorphicthermally dimorphic
Fungal species that can take both forms (depending on temperature or other conditions) are called dimorphic fungi ("dimorphic" means "having two forms").
Dimorphic fungi are fungi that can exist in the form of both mold and yeast.

Charles Louis Fleischmann

Charles FleischmannCharles Fleischmann & SonsCharles L. Fleischmann
In the United States, naturally occurring airborne yeasts were used almost exclusively until commercial yeast was marketed at the Centennial Exposition in 1876 in Philadelphia, where Charles L. Fleischmann exhibited the product and a process to use it, as well as serving the resultant baked bread.
Charles Louis Fleischmann (November 3, 1835 – December 10, 1897) was an innovative manufacturer of yeast and other consumer food products during the 19th century.

Basidiomycota

Basidiomycetesbasidiomycetebasidiomycetous
The term "yeast" is often taken as a synonym for Saccharomyces cerevisiae, but the phylogenetic diversity of yeasts is shown by their placement in two separate phyla: the Ascomycota and the Basidiomycota.
Basidiomycota are filamentous fungi composed of hyphae (except for basidiomycota-yeast; refer to yeast for more information) and reproduce sexually via the formation of specialized club-shaped end cells called basidia that normally bear external meiospores (usually four).

Theodor Schwann

SchwannTheodore SchwannTheodor Ambrose Hubert Schwann
Theodor Schwann recognized them as fungi in 1837.
Other contributions include the discovery of Schwann cells in the peripheral nervous system, the discovery and study of pepsin, the discovery of the organic nature of yeast, and the invention of the term metabolism.

Cell growth

proliferationcell proliferationgrowth
In 1857, French microbiologist Louis Pasteur showed that by bubbling oxygen into the yeast broth, cell growth could be increased, but fermentation was inhibited – an observation later called the "Pasteur effect".
The relationship between cell size and cell division has been extensively studied in yeast.

Leucosporidium frigidum

For example, Leucosporidium frigidum grows at -2 to 20 C, Saccharomyces telluris at 5 to 35 C, and Candida slooffi at 28 to 45 C. The cells can survive freezing under certain conditions, with viability decreasing over time.
Leucosporidium frigidum is a species of yeast that belongs to the genus of fungi Leucosporidium, and the family Leucosporidiaceae.

Multicellular organism

multicellularmulticellular organismsmulticellularity
Yeasts are unicellular organisms that evolved from multicellular ancestors, with some species having the ability to develop multicellular characteristics by forming strings of connected budding cells known as pseudohyphae or false hyphae.
Fungi are predominantly multicellular, though early diverging lineages are largely unicellular (e.g., Microsporidia) and there have been numerous reversions to unicellularity across fungi (e.g., Saccharomycotina, Cryptococcus, and other yeasts).

Rhodotorula

Rhodotorula glutinisRhodotorula rubra
Yeasts, including Candida albicans, Rhodotorula rubra, Torulopsis and Trichosporon cutaneum, have been found living in between people's toes as part of their skin flora.
Rhodotorula is a genus of unicellular pigmented yeasts, part of the division Basidiomycota.

Pasteur effect

In 1857, French microbiologist Louis Pasteur showed that by bubbling oxygen into the yeast broth, cell growth could be increased, but fermentation was inhibited – an observation later called the "Pasteur effect".
The effect was discovered in 1857 by Louis Pasteur, who showed that aerating yeasted broth causes yeast cell growth to increase, while conversely, fermentation rate decreases.

Saccharomyces

brewer's yeastSaccharomyces fragilis
The fungicide cycloheximide is sometimes added to yeast growth media to inhibit the growth of Saccharomyces yeasts and select for wild/indigenous yeast species.
Saccharomyces is a genus of fungi that includes many species of yeasts.

Candida (fungus)

CandidaCandida rugosaTorulopsis
Yeasts, including Candida albicans, Rhodotorula rubra, Torulopsis and Trichosporon cutaneum, have been found living in between people's toes as part of their skin flora. Most were members of the genus Candida; the most common species in honey stomachs was Dekkera intermedia and in flower nectaries, Candida blankii.
Candida is a genus of yeasts and is the most common cause of fungal infections worldwide.

Candida blankii

C. blankii
Most were members of the genus Candida; the most common species in honey stomachs was Dekkera intermedia and in flower nectaries, Candida blankii.
Candida blankii is a species of budding yeast (Saccharomycotina) in the family Saccharomycetaceae.

Killer yeast

killer factorskiller toxinmycocins
(See main article on killer yeast.) This can cause problems for winemaking but could potentially also be used to advantage by using killer toxin-producing strains to make the wine.
A killer yeast is a yeast, such as Saccharomyces cerevisiae, which is able to secrete one of a number of toxic proteins which are lethal to susceptible cells.

Model organism

animal modelmouse modelanimal models
It is also a centrally important model organism in modern cell biology research, and is one of the most thoroughly researched eukaryotic microorganisms.
The cell cycle in a simple yeast is very similar to the cell cycle in humans and is regulated by homologous proteins.

Trichosporon

Trichosporon cutaneumTrichosporon mycotoxinvorans
Yeasts, including Candida albicans, Rhodotorula rubra, Torulopsis and Trichosporon cutaneum, have been found living in between people's toes as part of their skin flora.
All species of Trichosporon are yeasts with no known teleomorphs (sexual states).

Saccharomyces telluris

For example, Leucosporidium frigidum grows at -2 to 20 C, Saccharomyces telluris at 5 to 35 C, and Candida slooffi at 28 to 45 C. The cells can survive freezing under certain conditions, with viability decreasing over time.
Saccharomyces telluris is a species of yeast also known as Kazachstania telluris.

Carbon dioxide

CO 2 CO2carbon dioxide (CO 2 )
The yeast species Saccharomyces cerevisiae converts carbohydrates to carbon dioxide and alcohols a process known as fermentation.
Yeast metabolizes sugar to produce and ethanol, also known as alcohol, as follows:

Malt

malted barleymalt extractbarley malt
Home brewers who cultivate yeast frequently use dried malt extract and agar as a solid growth medium.
It also develops other enzymes, such as proteases, that break down the proteins in the grain into forms that can be used by yeast.

Fructose

D-fructosefructose metabolism, inborn errors L -fructose
Carbon is obtained mostly from hexose sugars, such as glucose and fructose, or disaccharides such as sucrose and maltose.
Fructose may be anaerobically fermented by yeast or bacteria.

Baker's yeast

yeastbaking yeastbudding yeast
Many types of yeasts are used for making many foods: baker's yeast in bread production, brewer's yeast in beer fermentation, and yeast in wine fermentation and for xylitol production.
Baker's yeast is the common name for the strains of yeast commonly used in baking bread and bakery products, serving as a leavening agent which causes the bread to rise (expand and become lighter and softer) by converting the fermentable sugars present in the dough into carbon dioxide and ethanol.