Geomyces

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Geomyces
Scientific classification
Kingdom:
Fungi
Division:
Ascomycota
Class:
Leotiomycetes
Order:
Helotiales
Family:
Myxotrichaceae
Genus:
Geomyces

Traaen (1914)
Type species
Geomyces auratus
Traaen (1914)

Geomyces is a genus of filamentous fungi in the family Myxotrichaceae. Members of the genus are widespread in distribution, especially in northern temperate regions. [1] Known to be psychrotolerant and associated with Arctic permafrost soils, [2] [3] they are equally prevalent in the air of domestic dwellings, [4] and children's sandpits. [5] Species of Geomyces have previously been placed in the genus Chrysosporium . [6]

Contents

Description

This genus is characterized by short but distinct branched conidiophores that have chains of spores formed directly from the cells of the branches. [7] Sometimes only the tips of the branches become spores. The spores (conidia) are 1-celled, and either white or yellow. [7] The teleomorph of species in this genus, if they exist, are in Pseudogymnoascus or Gymnostellatospora .

Geomyces species are known to form ericoid mycorrhizae with the roots of alpine Ericales and other perennial hosts, helping these plants adapt to low-nutrient environments. [8]

The Geomyces are keratinophilic fungi, able to degrade hairs and nails. They have been investigated for possible use in the biodecomposition of waste poultry feathers. [9]

Adaptive capabilities

Research has shown that laboratory cultures of G. pannorum isolated from various environments may have extreme differences in morphology and physiology. In fact, the limits of cold adaptation in a particular isolate can vary depending on the source of isolation, even though the isolates are genetically identical. [10]

Studies suggest that one biochemical mechanism of low-temperature tolerance is achieved by altering the composition and total content of fatty-acids in their membrane, [11] [12] a phenomenon called homeoviscous adaptation.

White-nose syndrome

A 2008 study of white-nose syndrome, a fungal infection causing high mortality rates in bats, determined that the fungus found on the muzzles, wings, and ears of infected bats is a member of the genus Geomyces. [3] Later, the conidial morphology of this isolate was shown to be morphologically distinct from the conidia of other characterized members of the genus, despite the phylogenetic similarity. [2] Finally, in spring 2009 the source of the infection was identified as a new species, Geomyces destructans . [13] It is known however that Geomyces species are found in caves and bat hibernacula, [14] and have been isolated from the cave cricket Troglophilus neglectus. [15]

Biocorrosion

Using phylogenetic analyses of ribosomal DNA sequences, Geomyces species have been implicated in the biodeterioration of antique and optical glass. [16] Feeding off organic residues ubiquitously present on historical glass, such as dust or dead fungal and bacterial material, [17] fungal colonization by Geomyces may ultimately lead to etching, pit corrosion, or the formation of cracks or patinas due to secretion of acidic metabolic byproducts, or penetration of fungal mycelia into the paint layer. [18]

Bioactive compounds

A number of asterric acid derivatives, some with antibacterial or antifungal activity, have been isolated from an unidentified Geomyces isolate found in a soil sample from King George Island, Antarctica: ethyl asterrate, n-butyl asterrate, and geomycins A-C. [19]

Species

This species is ubiquitous in soil, from temperate to Antarctic regions, and is the predominant micro-organism associated with the degradation of soil-buried polyester polyurethane in landfills. [6] [20] The variant G. pannorum var. pannorum is occasionally reported as an etiological agent of superficial infection of skin and nails in humans. [21]
Named for the purplish-red or vinaceous colony color. The teleomorph form is Pseudogymnoascus roseus .

Related Research Articles

Ericoid mycorrhiza Species of fungus

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 species in the Ericaceae typically inhabit, including boreal forests, bogs, and heathlands. Molecular clock estimates suggest that the symbiosis originated approximately 140 million years ago.

<i>Aspergillus terreus</i> Species of fungus

Aspergillus terreus, also known as Aspergillus terrestris, is a fungus (mold) found worldwide in soil. Although thought to be strictly asexual until recently, A. terreus is now known to be capable of sexual reproduction. This saprotrophic fungus is prevalent in warmer climates such as tropical and subtropical regions. Aside from being located in soil, A. terreus has also been found in habitats such as decomposing vegetation and dust. A. terreus is commonly used in industry to produce important organic acids, such as itaconic acid and cis-aconitic acid, as well as enzymes, like xylanase. It was also the initial source for the drug mevinolin (lovastatin), a drug for lowering serum cholesterol.

<i>Trichophyton</i> Genus of Fungi

Trichophyton is a genus of fungi, which includes the parasitic varieties that cause tinea, including athlete's foot, ringworm, jock itch, and similar infections of the nail, beard, skin and scalp. Trichophyton fungi are molds characterized by the development of both smooth-walled macro- and microconidia. Macroconidia are mostly borne laterally directly on the hyphae or on short pedicels, and are thin- or thick-walled, clavate to fusiform, and range from 4 to 8 by 8 to 50 μm in size. Macroconidia are few or absent in many species. Microconidia are spherical, pyriform to clavate or of irregular shape, and range from 2 to 3 by 2 to 4 μm in size.

<i>Fusarium solani</i> Species of fungus

Fusarium solani is a species complex of at least 26 closely related filamentous fungi in the division Ascomycota, family Nectriaceae. It is the anamorph of Nectria haematococca. It is a common soil fungus and colonist of plant materials. Fusarium solani is implicated in plant disease as well as human disease notably infection of the cornea of the eye.

White-nose syndrome

White-nose syndrome (WNS) is an emerging 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 distinctive fungal growth around the muzzles and on the wings of hibernating bats. It was first identified from a February 2006 photo taken in a cave located in Schoharie County, New York. The syndrome has rapidly spread since then, however. In early 2018, it was identified in 33 U.S. states and seven Canadian provinces; plus the fungus, albeit sans syndrome, had been found in three additional states. Most cases are in the eastern half of both countries, but in March 2016, it was confirmed in a little brown bat in Washington state. In 2019, evidence of the fungus was detected in California for the first time, although no affected bats were found.

<i>Lomentospora prolificans</i> Species of fungus

Lomentospora prolificans is an emerging opportunistic fungal pathogen that causes a wide variety of infections in immunologically normal and immunosuppressed people and animals. It is resistant to most antifungal drugs and infections are often fatal. Drugs targeting the Class II dihydroorotate dehydrogenase (DHODH) proteins of L. prolificans, Scedosporium, Aspergillus and other rare moulds are the basis for at least one new therapy, Olorofim, which is currently in phase 2b clinical trials and has received breakthrough status by FDA. For information on all DHODH proteins, please see Dihydroorotate dehydrogenase.

<i>Pseudogymnoascus destructans</i>

Pseudogymnoascus 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 Canada. Unlike species of Geomyces, P. destructans forms asymmetrically curved conidia. Pseudogymnoascus destructans grows very slowly on artificial media and cannot grow at temperatures above 20 °C. It can grow around 4 °C to 20 °C, which encompasses the temperatures found in winter bat hibernacula. Phylogenic evaluation has revealed this organism should be reclassified under the family Pseudeurotiaceae, changing its name to Pseudogymnoascus destructans.

<i>Wallemia ichthyophaga</i> Species of fungus

Wallemia ichthyophaga is one of the three species of fungi in the genus Wallemia, which in turn is the only genus of the class Wallemiomycetes. The phylogenetic origin of the lineage was placed to various parts of Basidiomycota, but according to the analysis of larger datasets it is a (495-million-years-old) sister group of Agaricomycotina. Although initially believed to be asexual, population genomics found evidence of recombination between strains and a mating type locus was identified in all sequenced genomes of the species.

<i>Aphanoascus fulvescens</i> Species of fungus

Aphanoascus fulvescens is a mould fungus that behaves as a keratinophilic saprotroph and belongs to the Ascomycota. It is readily isolated from soil and dung containing keratin-rich tissues that have been separated from their animal hosts. This organism, distributed worldwide, is most commonly found in areas of temperate climate, in keeping with its optimal growth temperature of 28 °C (82 °F). While A. fulvescens is recognized as a geophilic fungal species, it is also a facultative opportunistic pathogen. Although it is not a dermatophyte, A. fulvescens has occasionally been shown to cause onychomycosis infections in humans. Its recognition in the laboratory is clinically important for correct diagnosis and treatment of human dermal infections.

<i>Pseudogymnoascus</i> Genus of fungi

Pseudogymnoascus is a genus of fungi in the family Pseudeurotiaceae.

<i>Chrysosporium keratinophilum</i> Species of fungus

Chrysosporium keratinophilum is a mold that is closely related to the dermatophytic fungi and is mainly found in soil and the coats of wild animals to break down keratin. Chrysosporium keratinophilum is one of the more commonly occurring species of the genus Chrysosporium in nature. It is easily detected due to its characteristic "light-bulb" shape and flat base. Chrysosporium keratinophilum is most commonly found in keratin-rich, dead materials such as feathers, skin scales, hair, and hooves. Although not identified as pathogenic, it is a regular contaminant of cutaneous specimens which leads to the common misinterpretation that this fungus is pathogenic.

<i>Aspergillus ustus</i> Species of fungus

Aspergillus ustus is a microfungus and member of the division Ascomycota. It is commonly found in indoor environments and soil. Isolated cases of human infection resulting from A. ustus have been described; however the majority of these are nail infections.

<i>Geomyces pannorum</i> Species of fungus

Geomyces pannorum is a yellow-brown filamentous fungus of the phylum Ascomycota commonly found in cold soil environments including the permafrost of the Northern hemisphere. A ubiquitous soil fungus, it is the most common species of the genus Geomyces; which also includes G. vinaceus and G. asperulatus. Geomyces pannorum has been identified as an agent of disfigurement of pigments used in the 15,000-year-old paintings on the walls of the Lascaux caves of France. Strains of Geomyces have been recovered from the Alaskan Fox Permafrost Tunnel and radiocarbon dated to between 14,000 and 30,000 years old.

<i>Ophidiomyces ophiodiicola</i> Species of fungus

Ophidiomyces ophiodiicola is a keratinophilic fungus from the family Onygenaceae of the order Onygenales. O. ophiodiicola is an emerging pathogen of captive and wild snakes in North America and Europe. It is reported to cause ophidiomycosis in many different species of snakes; clinical signs include skin swelling, crusts, and nodules of the skin. The mode of transmission is unknown, but is speculated to occur with direct contact between snakes or with the contaminated environment. Currently no treatment for O. ophiodiicola is available. O. ophiodiicola was identified by Sigler, Hambleton & Paré in 2013. O. ophiodiicola is the only species in the genus Ophidiomyces. It was previously known as Chrysosporium ophiodiicola and is closely related to Chrysosporium anamorph Nannizziopsis vriesii (CANV).

Petriella setifera is a fungus commonly found in soil and feces. The fungus has also been located on wood rot, plant species, and compost. A significant portion of P. setifera reports are found on sources with no previous association with the fungus. There are no known human cases of fungal infection, but one reported case of a dolphin infection. The fungus may have immunosuppressive characteristics, but it has not been confirmed. Many properties of the fungus are unknown, requiring further research.

<i>Epidermophyton floccosum</i> Species of fungus

Epidermophyton floccosum is a filamentous fungus that causes skin and nail infections in humans. This anthropophilic dermatophyte can lead to diseases such as tinea pedis, tinea cruris, tinea corporis and onychomycosis. Diagnostic approaches of the fungal infection include physical examination, culture testing, and molecular detection. Topical antifungal treatment, such as the use of terbinafine, itraconazole, voriconazole, and ketoconazole, is often effective.

<i>Phialophora fastigiata</i> Species of fungus

Phialophora fastigiata is a mitosporic, saprophytic fungus commonly found in soil, and on wood, and wood-pulp. This species was initially placed in the genus Cadophora but was later transferred to the genus Phialophora based on morphological and growth characteristics. In culture, P. fastigiata produces olive-brown, velvety colonies. The fungus is recognizable microscopically due to the presence of distinctive, funnel-shaped cuffs (collarettes) encircling the tips of phialides that bear slimy conidia. The fungus is often implicated in soft-rot wood decay due to its ability to degrade lignin, cellulose and pectin. It has also been reported to cause blue staining of wood and wood pulp.

Ctenomyces serratus is a keratinophilic fungal soil saprotroph classified by the German mycologist, Michael Emil Eduard Eidam in 1880, who found it growing on an old decayed feather. Many accounts have shown that it has a global distribution, having been isolated in select soils as well as on feathers and other substrates with high keratin content. It has also been found in indoor dust of hospitals and houses in Kanpur, Northern India and as a common keratinophilic soil fungus in urban Berlin. This species has been associated with nail infections in humans as well as skin lesions and slower hair growth in guinea pigs.

<i>Uncinocarpus reesii</i> Species of fungus

Uncinocarpus reesii is a species of saprotrophic microfungi that grows in soil and on keratinous materials such as hair, feathers and skin. It was the first species to be designated as part of the genus Uncinocarpus, owing in part to its characteristic development of hooked (uncinate) appendages. As the closest non-pathogenic relative of Coccidioides immitis and C. posadasii, it has become a subject of research interest.

Myriodontium keratinophilum is a fungus widespread in nature, most abundantly found in keratin-rich environments such as feathers, nails and hair. Despite its ability to colonize keratinous surfaces of human body, the species has been known to be non-pathogenic in man and is phylogentically distant to other human pathogenic species, such as anthropophilic dermatophytes. However, its occasional isolation from clinical specimens along with its keratinolytic properties suggest the possibility it may contribute to disease.

References

  1. ↑ Bisby, Guy Richard; Ainsworth, G. C.; Kirk, P. M.; Aptroot, André (2001). Ainsworth & Bisby's Dictionary of the fungi / by P. M. Kirk... [et al.]; with the assistance of A. Aptroot... [et al.] Oxon: CAB International. ISBN   978-0-85199-377-5.
  2. 1 2 Blehert DS, Hicks AC, Behr M, et al. (October 2008). "Bat White-Nose Syndrome: An Emerging Fungal Pathogen?". Science. 323 (5911): 227. doi:10.1126/science.1163874. PMID   18974316.
  3. 1 2 National Geographic : "Deadly Bat Disease Linked to Cold-Loving Fungus" . Retrieved 2008-11-02.
  4. ↑ Hunter, CA; Grant, C; Flannigan, B; Bravery, AF. (1988). "Mould in buildings. The air spora of domestic dwellings". International Biodeterioration. 24 (2): 81–102. doi:10.1016/0265-3036(88)90052-8.
  5. ↑ Marchisio, VF (1986). "Keratinolytic and keratinophlic fungi of children's sandpits in the city of Turin Italy". Mycopathologia. 94 (3): 163–172. doi:10.1007/bf00454595.
  6. 1 2 "Geomyces pannorum". Archived from the original on 2011-07-06. Retrieved 2008-11-02.
  7. 1 2 "Geomyces". Archived from the original on 2008-02-23. Retrieved 2008-12-07.
  8. ↑ Dalpe, Y; Litton, W; Sigler, L. (1989). "Scyalidium vaccinii sp. nov., an ericoid endophyte of Vaccinium angustifolium roots". Mycotaxon . 35: 371–377.
  9. ↑ Saxena, P; Kumar, A; Shrivastava, JN. (2005). "Keratinophilic fungi: A microbial way to manage poultry waste feathers". Indian Journal of Microbiology. 45 (2): 151–154.
  10. ↑ Kochkina, GA; Ivanushkina, NE; Akimov, VN; Gilichinskii, DA; Ozerskaya, SM. (2007). "Halo- and psychrotolerant Geomyces fungi from Arctic cryopegs and marine deposits". Microbiology. 76 (1): 31–38. doi:10.1134/s0026261707010055.
  11. ↑ Finottei, E; Moretto, D; Marsella, R; Mercantini, R. (1993). "Temperature effects and fatty-acid patterns in Geomyces species isolated from Antarctic soil". Polar Biology. 13 (2): 127–130. doi:10.1007/bf00238545.
  12. ↑ Weinstein, RN; Montiel, PO; Johnstone, K. (2000). "Influence of growth temperature on lipid and soluble carbohydrate synthesis by fungi isolated from Fellfield soil in the maritime Antarctic". Mycologia . 92 (2): 222–229. doi:10.2307/3761554. JSTOR   3761554.
  13. ↑ Gargas A, Trest MT, Christensen M, Volk TJ, Blehert DS (April–June 2009). "Geomyces destructans sp. nov. associated with bat white-nose syndrome" (PDF). Mycotaxon. 108: 147–154. doi:10.5248/108.147. Archived from the original (PDF) on 2012-09-15. Retrieved 2009-09-03.
  14. ↑ Mosca, AML; Campanino, F. (1962). "Soil mycological analyses of natural caves in the Piedmont". Allonia. 8: 27–43.
  15. ↑ Gunde-Cimerman, N; Zalar, P; Glavan, G; Cimerman, A. (1996). "Extracellular enzymatic activities of fungi isolated from the cave cricket Troglophilus neglectus". Mededelingen Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen Universiteit Gent. 61 (4A–B): 1425–1426.
  16. ↑ Schabereiter-Gurtner, C; Piñar, G; Lubitz, W; Rölleke, S. (2001). "Analysis of fungal communities on historical church window glass by denaturing gradient gel electrophoresis and phylogenetic 18S rDNA sequence analysis". Journal of Microbiological Methods. 47 (3): 345–354. doi:10.1016/s0167-7012(01)00344-x.
  17. ↑ Karpovich-Tate, N; Rebrikova, NL. (1990). "Microbial communities on damaged frescoes and building materials in the cathedral of the nativity of the virgin in the Pafnutii-Borovskii monastery". Russia. Int. Biodeterior. 27 (3): 281–296. doi:10.1016/0265-3036(91)90057-x.
  18. ↑ Berner, M; Wanner, G; Lubitz, W. (1997). "A comparative study of the fungal flora present in medieval wall paintings in the chapel of the castle Herberstein and in the parish church of St. Georgen in Styria, Austria". Int. Biodeterior. Biodegrad. 40: 53–61. doi:10.1016/s0964-8305(97)00062-0.
  19. ↑ Li Y, Sun B, Liu S, Jiang L, Liu X, Zhang H, Che Y (September 2008). "Bioactive asterric acid derivatives from the Antarctic ascomycete fungus Geomyces sp". J. Nat. Prod. 71 (9): 1643–6. doi:10.1021/np8003003. PMID   18720971.
  20. ↑ Cosgrove L, McGeechan PL, Robson GD, Handley PS (September 2007). "Fungal Communities Associated with Degradation of Polyester Polyurethane in Soil". Applied and Environmental Microbiology. 73 (18): 5817–24. doi:10.1128/AEM.01083-07. PMC   2074895 . PMID   17660302.
  21. ↑ Gianni C, Caretta G, Romano C (2003). "Skin infection due to Geomyces pannorum var. pannorum". Mycoses. 46 (9–10): 430–2. doi:10.1046/j.1439-0507.2003.00897.x. PMID   14622395.
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