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The fungi imperfecti or imperfect fungi, are
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 ...
which do not fit into the commonly established
taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...
classifications of fungi that are based on
biological species concept The species problem is the set of questions that arises when biologists attempt to define what a species is. Such a definition is called a species concept; there are at least 26 recognized species concepts. A species concept that works well for se ...
s or morphological characteristics of sexual structures because their sexual form of
reproduction Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual or ...
has never been observed. They are known as imperfect fungi because only their asexual and vegetative phases are known. They have asexual form of reproduction, meaning that these fungi produce their spores asexually, in the process called
sporogenesis Sporogenesis is the production of spores in biology. The term is also used to refer to the process of reproduction via spores. Reproductive spores were found to be formed in eukaryotic organisms, such as plants, algae and fungi, during their norma ...
. There are about 25,000 species that have been classified in the deuteromycota and many are basidiomycota or ascomycota
anamorphs 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 ...
. Fungi producing the antibiotic
penicillin Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from ''Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by P. chrysogenum using ...
and those that cause
athlete's foot Athlete's foot, known medically as ''tinea pedis'', is a common skin infection of the feet caused by a fungus. Signs and symptoms often include itching, scaling, cracking and redness. In rare cases the skin may blister. Athlete's foot fungus ...
and
yeast infection Candidiasis is a fungal infection due to any type of '' Candida'' (a type of yeast). When it affects the mouth, in some countries it is commonly called thrush. Signs and symptoms include white patches on the tongue or other areas of the mouth ...
s are algal fungi. In addition, there are a number of edible imperfect fungi, including the ones that provide the distinctive characteristics of
Roquefort Roquefort is a sheep milk cheese from Southern France, and is one of the world's best known blue cheeses. Though similar cheeses are produced elsewhere, EU law dictates that only those cheeses aged in the natural Combalou caves of Roquefort-sur ...
and Camembert cheese. Other, more informal names besides Deuteromycota ("Deuteromycetes") and fungi imperfecti are anamorphic fungi, or mitosporic fungi, but these are terms without taxonomic rank. Examples are Alternaria, Colletotrichum, Trichoderma etc.


Problems in taxonomic classification

Although Fungi imperfecti/Deuteromycota is no longer formally accepted as a
taxon In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
, many of the fungi it included have yet to find a place in modern fungal classification. This is because most
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 ...
are classified based on characteristics of the fruiting bodies and spores produced during sexual reproduction, and members of the Deuteromycota have been observed to reproduce only asexually or produce no spores.
Mycologists Mycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans, including as a source for tinder, traditional medicine, food, and entheogens, ...
are unique among those who study extant organisms in using a dual system of nomenclature. Dual naming was permitted by Article 59 of the
International Code of Botanical Nomenclature The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "trad ...
(which governs the naming of plants and fungi); however, this was abolished in the 2011 update of the Code. Under the former system, a name for an asexually reproducing fungus was considered a ''form taxon''. For example, the ubiquitous and industrially important mold, ''
Aspergillus niger ''Aspergillus niger'' is a mold classified within the ''Nigri'' section of the ''Aspergillus'' genus. The ''Aspergillus'' genus consists of common molds found throughout the environment within soil and water, on vegetation, in fecal matter, on de ...
'', has no known sexual cycle. Thus ''Aspergillus niger'' is considered a form taxon. In contrast, isolates of its close relative, ''
Aspergillus nidulans ''Aspergillus nidulans'' (also called ''Emericella nidulans'' when referring to its sexual form, or teleomorph) is one of many species of filamentous fungi in the phylum Ascomycota. It has been an important research organism for studying eukaryo ...
'', revealed it to be the anamorphic stage of 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 ...
(the
ascocarp 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 m ...
or fruiting body of the sexual reproductive stage of a fungus), which was already named ''Emericella nidulans''. When such a teleomorphic stage is known, that name will take priority over the name of an
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 ...
(which lacks a sexual reproductive stage). Hence the formerly classified ''Aspergillus'' species is now properly called ''Emericella nidulans''.


Phylogeny and taxonomy

Phylogenetic classification of asexually reproducing fungi now commonly uses
molecular systematics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
.
Phylogenetic tree A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...
s constructed from comparative analyses of
DNA sequence DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. Th ...
s, such as
rRNA Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosoma ...
, or multigene phylogenies may be used to infer relationships between asexually reproducing fungi and their sexually reproducing counterparts. With these methods, many asexually reproducing fungi have now been placed in the tree of life. However, because phylogenetic methods require sufficient quantities of biological materials (spores or fresh specimens) that are from pure (i.e., uncontaminated) fungal cultures, for many asexual species their exact relationship with other fungal species has yet to be determined. Under the current system of fungal nomenclature,
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 ...
names cannot be applied to fungi that lack sexual structures. Classifying and naming asexually reproducing fungi is the subject of ongoing debate in the mycological community.


Historical classification of the imperfect fungi

These groups are no longer formally accepted because they do not adhere to the principle of
monophyly In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...
. The taxon names are sometimes used informally. In particular, the term 'hyphomycetes' is often used to refer to molds, and the term 'coelomycetes' is used to refer to many asexually reproducing plant pathogens that form discrete fruiting bodies. Following, a classification of the Fungi imperfecti: Saccardo et al.(1882-1972) * Class
Hyphomycetes Hyphomycetes are a form classification of fungi, part of what has often been referred to as fungi imperfecti, Deuteromycota, or anamorphic fungi. Hyphomycetes lack closed fruit bodies, and are often referred to as moulds (or molds). Most hyph ...
lacking fruiting bodies ** Order Moniliales (producing spores on simple
conidiophore A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an Asexual reproduction, asexual, non-motility, motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are al ...
s) ** Order Stilbellales (producing spores on
synnema A synnema (plural ''synnemata'', also ''coremia''; derivation: "Threads together") is a large, erect reproductive structure borne by some fungi, bearing compact conidiophore A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamy ...
ta) ** Order Tuberculariales (producing spores in sporodochia) * Class
Coelomycetes Coelomycetes are a form-class of fungi, part of what has often been referred to as Fungi imperfecti, Deuteromycota, or anamorphic fungi. These are conidial fungi where the conidia form in a growing cavity in the host's tissue. The fruiting str ...
spores produced in fruiting bodies ** Order Melanconiales (producing spores in
acervuli An acervulus (pl. acervuli) is a small asexual fruiting body that erupts through the epidermis of host plants parasitised by mitosporic fungi of the form order Melanconiales ( Deuteromycota, Coelomycetes). It has the form of a small cushion at ...
) ** Order
Sphaeropsidales Sphaeropsidales is an order of Coelomycetes fungi. These are conidial fungi where the conidia form in a growing cavity in the host's tissue. The fruiting structures are spherical with an opening at the apex (pycnidia). Four form-families can ...
(producing spores in
pycnidia A pycnidium (plural pycnidia) is an asexual fruiting body produced by mitosporic fungi, for instance in the order Sphaeropsidales ( Deuteromycota, Coelomycetes) or order Pleosporales (Ascomycota, Dothideomycetes). It is often spherical or inve ...
) * Class Agonomycetes lacking spores Other, according to Dörfelt (1989): * ''Form-Klasse:''
Hyphomycetes Hyphomycetes are a form classification of fungi, part of what has often been referred to as fungi imperfecti, Deuteromycota, or anamorphic fungi. Hyphomycetes lack closed fruit bodies, and are often referred to as moulds (or molds). Most hyph ...
** ''Form-Ordnung:'' Agonomycetales *** ''Form-Familie:'' Agonomycetaceae ** ''Form-Ordnung:'' Moniliales *** ''Form-Familie:'' Moniliaceae *** ''Form-Familie:'' Dematiaceae *** ''Form-Familie:'' Stilbellaceae *** ''Form-Familie:'' Tuberculariaceae * ''Form-Klasse:''
Coelomycetes Coelomycetes are a form-class of fungi, part of what has often been referred to as Fungi imperfecti, Deuteromycota, or anamorphic fungi. These are conidial fungi where the conidia form in a growing cavity in the host's tissue. The fruiting str ...
** ''Form-Ordnung:'' Melanconiales *** ''Form-Familie:'' Melanconiaceae ** ''Form-Ordnung:''
Sphaeropsidales Sphaeropsidales is an order of Coelomycetes fungi. These are conidial fungi where the conidia form in a growing cavity in the host's tissue. The fruiting structures are spherical with an opening at the apex (pycnidia). Four form-families can ...
*** ''Form-Familie:'' Sphaeropsidaceae Other systems of classification are reviewed by .


Common species


Industrially relevant fungi

* ''
Tolypocladium inflatum ''Tolypocladium inflatum'' is an ascomycete fungus originally isolated from a Norwegian soil sample that, under certain conditions, produces the immunosuppressant drug ciclosporin. In its sexual stage ( teleomorph) it is a parasite on scarab b ...
'' → from which the
immunosuppressant Immunosuppressive drugs, also known as immunosuppressive agents, immunosuppressants and antirejection medications, are drugs that inhibit or prevent activity of the immune system. Classification Immunosuppressive drugs can be classified in ...
ciclosporin Ciclosporin, also spelled cyclosporine and cyclosporin, is a calcineurin inhibitor, used as an immunosuppressant medication. It is a natural product. It is taken orally or intravenously for rheumatoid arthritis, psoriasis, Crohn's disease, ...
is obtained; * ''
Penicillium griseofulvum ''Penicillium griseofulvum'' is a species of the genus of ''Penicillium'' which produces patulin, penifulvin A, cyclopiazonic acid, roquefortine C, shikimic acid, griseofulvin, and 6-Methylsalicylic acid (via a polyketide synthase Polyketides ...
'' * ''
Penicillium roqueforti ''Penicillium roqueforti'' is a common saprotrophic fungus in the genus ''Penicillium''. Widespread in nature, it can be isolated from soil, decaying organic matter, and plants. The major industrial use of this fungus is the production of blue ...
'' * ''
Penicillium camemberti ''Penicillium camemberti'' is a species of fungus in the genus ''Penicillium''. It is used in the production of Camembert, Brie, Langres, Coulommiers, and Cambozola cheeses, on which colonies of ''P. camemberti'' form a hard, white crust. I ...
'' * Other species of ''Penicillium'' are used to improve both the taste and the texture of
cheese Cheese is a dairy product produced in wide ranges of flavors, textures, and forms by coagulation of the milk protein casein. It comprises proteins and fat from milk, usually the milk of cows, buffalo, goats, or sheep. During production, ...
s * ''
Aspergillus oryzae ''Aspergillus oryzae'', also known as , is a filamentous fungus (a mold) used in East Asia to saccharify rice, sweet potato, and barley in the making of alcoholic beverages such as ''sake'' and '' shōchū'', and also to ferment soybeans for m ...
'' * ''
Aspergillus sojae ''Aspergillus sojae'' is a species of fungus in the genus ''Aspergillus''. In Japan, it is used to make the ferment ( ''kōji'') of soy sauce, miso, mirin, and other lacto-fermented condiments such as ''tsukemono''. Soy sauce condiment is produ ...
'' * ''
Aspergillus niger ''Aspergillus niger'' is a mold classified within the ''Nigri'' section of the ''Aspergillus'' genus. The ''Aspergillus'' genus consists of common molds found throughout the environment within soil and water, on vegetation, in fecal matter, on de ...
'' * '' Amorphotheca resinae'' * ''Lecanicillium'' sp. → these produce conidia which may control certain species of insect
pests PESTS was an anonymous American activist group formed in 1986 to critique racism, tokenism, and exclusion in the art world. PESTS produced newsletters, posters, and other print material highlighting examples of discrimination in gallery represent ...
C

(in Spanish language, Spanish).
* Other
entomopathogenic fungi An entomopathogenic fungus is a fungus that can kill or seriously disable insects. Typical life cycle These fungi usually attach to the external body surface of insects in the form of microscopic spores (usually asexual, mitosporic spores also ...
, including ''
Metarhizium ''Metarhizium'' is a genus of entomopathogenic fungi in the Clavicipitaceae family. With the advent of genetic profiling, placing these fungi in proper taxa has now become possible. Most turn out to be the asexual forms (anamorphs) of fungi in ...
'' and ''
Beauveria ''Beauveria'' is a genus of asexually-reproducing fungi allied with the ascomycete family Cordycipitaceae. Its several species are typically insect pathogens. The sexual states (teleomorphs) of ''Beauveria'' species, where known, are species of ...
'' spp. * '' Pochonia'' spp. are under development for control of
Nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...
pests.


See also

*
Forest pathology Forest pathology is the research of both biotic and abiotic maladies affecting the health of a forest ecosystem, primarily fungal pathogens and their insect vectors. It is a subfield of forestry and plant pathology. Forest pathology is part ...
* List of mitosporic Ascomycota


References


Bibliography

* * * * * {{Taxonbar, from=Q648056 . Fungus common names Fungi by classification