''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of
yeast
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitut ...
s in the family
Pichiaceae
The Pichiaceae are a family of yeasts in the order Saccharomycetales. According to the 2007 Outline of Ascomycota, the family contains four genera, but GBIF lists 15 genera. The family was named by Zender in 1925.
Genera
As listed by GBIF;
* '' ...
with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a
teleomorph
In mycology, the terms teleomorph, anamorph, and holomorph apply to portions of the life cycles of fungi in the phyla Ascomycota and Basidiomycota:
*Teleomorph: the sexual reproductive stage (morph), typically a fruiting body.
*Anamorph: an ase ...
, and forms hat-shaped, hemispherical, or round
ascospore
An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or s ...
s during sexual reproduction. The
anamorph
In mycology, the terms teleomorph, anamorph, and holomorph apply to portions of the life cycles of fungi in the phyla Ascomycota and Basidiomycota:
*Teleomorph: the sexual reproductive stage (morph), typically a fruiting body.
*Anamorph: an ase ...
s of some ''Pichia'' species are ''
Candida'' species. The asexual reproduction is by multilateral budding.
The genus name of ''Pichia'' is in honour of Pico Pichi (1862-1933), who was an Italian
botanist
Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek wo ...
and Professor of natural history and
plant pathology
Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungus, fung ...
at a viticulture school in the town of
Conegliano
Conegliano (; Venetian: ''Conejan'') is a town and ''comune'' of the Veneto region, Italy, in the province of Treviso, about north by rail from the town of Treviso. The population of the city is of people. The remains of a 10th-century castle ar ...
in the
Province of Treviso
The Province of Treviso ('' it, Provincia di Treviso'') is a province in the Veneto region of Italy. Its capital is the city of Treviso. The province is surrounded by Belluno in the north, Vicenza in the west, Padua in southwest, Venice in the so ...
.
The genus was
circumscribed
In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius.
Not every polyg ...
by
Emil Christian Hansen
Emil Christian Hansen (8 May 1842 – 27 August 1909) was a Danish mycologist and fermentation physiologist.
Born in Ribe, he financed his education by writing novels. He was awarded a gold medal in 1876 for an essay on fungi, titled ''De dans ...
in Centralbl. Bakteriol., 2. Abt., 12 on pages 533-538 in 1904.
Lactose
Lactose is a disaccharide sugar synthesized by galactose and glucose subunits and has the molecular formula C12H22O11. Lactose makes up around 2–8% of milk (by mass). The name comes from ' (gen. '), the Latin word for milk, plus the suffix '' - ...
is neither fermented nor assimilated by these species. The behaviour with regard to other carbohydrates is dependent on the different species. Nitrate is always assimilated.
More than 100 species of this genus are known.
GBIF
The Global Biodiversity Information Facility (GBIF) is an international organisation that focuses on making scientific data on biodiversity available via the Internet using web services. The data are provided by many institutions from around the ...
lists 155.
Although some genera have been re-assigned from ''Pichia'' genera to the ''
Wickerhamomyces''; such as ''Wickerhamomyces canadensis'', ''W. ciferri'', ''W. lynferdii'', ''W. salvicola'' and ''W. subpelliculosa''. Many other ''Pichia'' genera have also been re-assigned to various genera such as; ''
Starmera'', ''
Cyberlindnera'', ''
Ogataea
''Ogataea'' is a genus of ascomycetous yeasts in the family Saccharomycetaceae. It was separated from the former genus '' Hansenula'' via an examination of their 18S and 26S rRNA partial base sequencings by Yamada et al. 1994.Y. Yamada, K. Maeda, ...
'' and others.
Species Fungorum
''Index Fungorum'' is an international project to index all formal names (scientific names) in the fungus kingdom. the project is based at the Royal Botanic Gardens, Kew, one of three partners along with Landcare Research and the Institute of Mi ...
accepts only 32 species (see below for list).
Some of them interfere with the fermentation process for alcohol production. In
winemaking
Winemaking or vinification is the production of wine, starting with the selection of the fruit, its fermentation into alcohol, and the bottling of the finished liquid. The history of wine-making stretches over millennia. The science of wine and ...
, some species of ''Pichia'' can create potential
faults in wines. Most are found in decaying plants; some live in close
symbiosis
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
with insects, which live on decaying plants.
Some ''Pichia'' representatives can be found in raw milk and cheese, such as ''
P. anomala'' (formerly named ''Hansenula anomala''). ''P. anomala'' has been shown to combat the undesirable mold ''
Aspergillus flavus
''Aspergillus flavus'' is a saprotrophic and pathogenic fungus with a cosmopolitan distribution. It is best known for its colonization of cereal grains, legumes, and tree nuts. Postharvest rot typically develops during harvest, storage, and/or t ...
'', which contaminates food sources such as tree nuts and corn, and produces
aflatoxins
Aflatoxins are various toxicity, poisonous carcinogens and mutagens that are produced by certain Mold (fungus), molds, particularly ''Aspergillus'' species. The fungi grow in soil, decaying vegetation and various staple food, staple foodstuffs a ...
. Researchers of the
Agricultural Research Service
The Agricultural Research Service (ARS) is the principal in-house research agency of the United States Department of Agriculture (USDA). ARS is one of four agencies in USDA's Research, Education and Economics mission area. ARS is charged with ext ...
found that when pistachio trees were treated with ''P. anomala'', the growth of ''A. flavus'' was inhibited up to 97%. In addition to inhibiting ''A. flavus'', the yeast may also help protect other agricultural crops from unwanted molds that affect the crop’s taste, texture, yield, and safety. In smeared-surface ripened cheese, the most important species is ''
P. membranifaciens'' that also occurs on cream cheese. The formation of a so-called pellicle is typical. Another member of the genus, ''
P. pastoris'', is widely used in molecular biology and biotechnology as an expression system. ''
P. angusta'' furthermore called ''Hansenula polymorpha'', is a model organism for studying the functions of
peroxisome
A peroxisome () is a membrane-bound organelle, a type of microbody, found in the cytoplasm of virtually all eukaryotic cells. Peroxisomes are oxidative organelles. Frequently, molecular oxygen serves as a co-substrate, from which hydrogen pero ...
s and their underlying molecular biology.
Some ''Pichia'' species (e.g. ''
P. ohmeri'') have recently been clinically proven to be pathogens, better known as so-called
opportunistic pathogens
An opportunistic infection is an infection caused by pathogens (bacteria, fungi, parasites or viruses) that take advantage of an opportunity not normally available. These opportunities can stem from a variety of sources, such as a weakened immune ...
Pichia Species
, Doctor Fungus, url accessed 2014-02-27 in immunocompromised
Immunodeficiency, also known as immunocompromisation, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that a ...
humans.
Species
As accepted by Species Fungorum
''Index Fungorum'' is an international project to index all formal names (scientific names) in the fungus kingdom. the project is based at the Royal Botanic Gardens, Kew, one of three partners along with Landcare Research and the Institute of Mi ...
;
* '' Pichia barkeri''
* '' Pichia cactophila''
* ''Pichia cecembensis
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round asc ...
''
* ''Pichia cephalocereana
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round asc ...
''
* ''Pichia deserticola
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round as ...
''
* '' Pichia eremophila''
* '' Pichia exigua''
* '' Pichia fermentans''
* '' Pichia galeiformis''
* '' Pichia garciniae''
* ''Pichia gijzeniarum
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round as ...
''
* '' Pichia heedii''
* '' Pichia kluyveri''
* ''Pichia megalospora
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round asc ...
''
* ''Pichia membranifaciens
''Pichia membranifaciens'' is a species of yeast.
References
External links
Saccharomycetes
Fungal strawberry diseases
Fungi described in 1904
{{Ascomycota-stub ...
''
* ''Pichia methanothermo
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round as ...
''
* '' Pichia myanmarensis''
* ''Pichia nakasei
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round as ...
''
* ''Pichia nanzhaoensis
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round as ...
''
* '' Pichia nongkratonensis''
* '' Pichia norvegensis''
* '' Pichia occidentalis''
* '' Pichia paraexigua''
* ''Pichia porticicola
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round as ...
''
* ''Pichia pseudocactophila
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round asc ...
''
* '' Pichia punctispora''
* ''Pichia rarassimilans
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round as ...
''
* '' Pichia scaptomyzae''
* ''Pichia scutulata
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round asc ...
''
* ''Pichia sporocuriosa
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round as ...
''
* '' Pichia terricola''
* ''Pichia uvarum
''Pichia'' (''Hansenula'' and ''Hyphopichia'' are obsolete synonyms) is a genus of yeasts in the family Pichiaceae with spherical, elliptical, or oblong acuminate cells. ''Pichia'' is a teleomorph, and forms hat-shaped, hemispherical, or round asc ...
''
References
External links
Pichia at Dr Fungus
Pichia in MycoBank.org
{{Taxonbar, from=Q125153
Saccharomycetaceae
Yeasts
Yeasts used in brewing