''Pseudogymnoascus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

fungi A fungus ( : 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. These organisms are classified as a kingdom, separately from ...

in the family Pseudeurotiaceae.

History

It was circumscribed by A. Raillo in 1929 for two species, ''P. roseus'' and ''P. vinaceus''. No

type specimens In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes t ...

were retained by Raillo. In 1972, Samson designated a neotype for ''P. roseus'', recognized three species (''P. roseus'' Raillo, ''P. bhattii'' Samson and ''P. caucasicus'' Cejp & Milko) and synonymized ''P. vinaceus'' with ''P. roseus''. In 1982, Müller described a fourth species, ''P. alpinus''. In 2006, Rice and Currah described two additional species, ''P. appendiculatus'' and ''P. verrucosus''. In 2013, ''

Geomyces destructans ''Pseudogymnoascus destructans'' (formerly known as ''Geomyces destructans'') is a psychrophilic (cold-loving) fungus that causes white-nose syndrome (WNS), a fatal disease that has devastated bat populations in parts of the United States and Can ...

'' the casual agent of bat

white nose syndrome White-nose syndrome (WNS) is a fungal disease in North American bats which has resulted in the dramatic decrease of the bat population in the United States and Canada, reportedly killing millions as of 2018. The condition is named for a distincti ...

was transferred to this genus and is now referred to as ''P. destructans''. Since 2006, intensive cave sampling has identified numerous ''Pseudogymnoascus'' isolates that have yet to be described.

Species Characteristics

''Pseudogymnoascus alpinus'' Müller

ascospores 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 ...

are described as navicular-fusiform in shape and hyaline to yellow in color. Typically, one side of the ascospore is flattened with 3 longitudinal rims. Müller collected ''P. alpinus'' from soil below Winter Heath in

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

. ''Pseudogymnoascus appendiculatus'' Rice & Currah differs from other ''Pseudogymnoascus'' species by the presence of long, pigmented, branched peridial appendages. The ascospores have a longitudinal rim or are otherwise described as smooth. This species was initially isolated from rotten

black spruce ''Picea mariana'', the black spruce, is a North American species of spruce tree in the pine family. It is widespread across Canada, found in all 10 provinces and all 3 territories. It is the official tree of the province of Newfoundland and Labra ...

wood found under

Sphagnum ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, peat moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store wa ...

peat in Canada. ''Pseudogymnoascus bhattii'' Samson has single-celled, hyaline to yellow fusiform ascospores which are described as flattened on one side. No

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 ...

(asexual state) was described. Samson isolated this species from

alpine tundra Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation, with an associated alpine climate, harsh climate. As the latitude of a location approaches the poles, the threshold elevation for alp ...

soil in Canada and Alaska and stated that it could grow from 10 °C to 25 °C. ''Pseudogymnoascus caucasicus'' Cejp & Milko described this species as having stalked chlamydospore-like structures and no

ascomata An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are mo ...

. This species was initially isolated from forest soil in

Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...

. In 1982, Müller noted that the type culture was sterile. ''

Pseudogymnoascus destructans ''Pseudogymnoascus destructans'' (formerly known as ''Geomyces destructans'') is a psychrophilic (cold-loving) fungus that causes white-nose syndrome (WNS), a fatal disease that has devastated bat populations in parts of the United States and Can ...

'' Minnis & Lindner was initially described in 2009 as ''Geomyces destructans'' by Gargas et al. In 2013, further analysis of the phylogenetic relationship moved this species to the genus ''Pseudogymnoascus''. The conidium of this species are hyaline and characteristically curved. Geomyces destructans in culture

This species was first isolated from infected hibernating bats in New York state. Recently, this species has been isolated from cave environments no longer inhabited by hibernating bats. ''Pseudogymnoascus roseus'' Raillo has smooth ascospores that are ellipsoid to fusiform and can vary from yellow to reddish brown.

Conidia A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the ...

are typically hyaline in color and globose to ellipsoid in shape. The base of the conidia are truncate. ''Pseudogymnoascus roseus'' is frequently isolated from soil, root and wood samples. ''Pseudogymnoascus verrucosus Rice & Currah'' is distinguished by the presence of warts that covers the ascospore surface. In contrast, the conidia are described as smooth to asperulate. This species was also isolated from the same substrate and locality as ''Pseudogymnoascus appendiculatus''.

Ecology

Many ''Pseudogymnoascus'' species are cellulolytic, function as

saprotrophs Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi (f ...

and are either

psychrophilic Psychrophiles or cryophiles (adj. ''psychrophilic'' or ''cryophilic'') are extremophilic organisms that are capable of growth and reproduction in low temperatures, ranging from to . They have an optimal growth temperature at . They are found in ...

or psychrotolerant. ''Pseudogymnoascus roseus'' was able to form an

ericoid mycorrhiza The ericoid mycorrhiza is a mutualistic relationship formed between members of the plant family Ericaceae and several lineages of mycorrhizal fungi. This symbiosis represents an important adaptation to acidic and nutrient poor soils that specie ...

l association ''in vitro'' and ''Pseudogymnoascus destructans'' infects hibernating bat and survives in the cave environment as a saprotroph. Müller indicated that all known ''Pseudogymnoascus'' species, prior to 1982, were not known to be keratinolytic.

References

External links

* {{Taxonbar, from=Q10643168 Dothideomycetes enigmatic taxa Dothideomycetes genera