Biology:Pseudeurotium ovale
| Pseudeurotium ovale | |
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| Genus: | Pseudeurotium
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| Species: | Pseudeurotium ovale
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| Binomial name | |
| Pseudeurotium ovale Mycotaxon: Doveri (2013)[1]
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Pseudeurotium ovale is a species of fungus.
History and taxonomy
Pseudeurotium ovale was first classified by Amelia C. Stolk in 1954.[5] It was assigned to the genus Pseudeurotium, along with thirteen other species.[6] It was initially classified as a member of the family Eurotiaceae, but was reclassified forty years later by Malloch and Cain to its current family, Pseudeurotiaceae.[6][7] Further more recent studies indicated that P. ovale could be classified as incertae sedis, as a result of analysis of conserved regions of its genome.[6] Pseudeurotium ovale was originally identified on Jersey, an island in the English Channel, but has since been isolated in various regions, including Japan, South Africa, Italy and Sweden.[8] Pseudeurotium ovale has been classified as a saprotroph, as it can thrive in a diverse set of environments, including soil, faeces and oatmeal agar.[5][9][10] In some instances, growths on the nematode Heterodera or Globodera rostochiensis have contained P. ovale.[5]
Growth and morphology
Pseudeurotium ovale is a member of the Ascomycota, and therefore the fruiting body of P. ovale is called an ascocarp.[9] Pseudeurotium ovale has a cleisothecium, or a fruiting body with a round shape.[9] The membrane of the cleisothecium is continuous, and the spore-bearing structures or asci, lack germ pores. These normally allow germ tubes to exit the ascospores after they disperse from the fruiting body, and germination begins.[9] The fungus germinates every 24 to 48 hours, and where the germ tube exits the fungal spores has yet to be identified.[5] P. ovale is very similar in appearance to both Cleistothelebolus nipigonensis and Cephalotheca palearum, however there are slight differences between their physical characteristics that make them identifiable.[5][9] The multilayered cell wall of Cephalotheca and the faecal-restricted growth environment for C. nipigonensis distinguish these fungi from P. ovale.[5][9]
Physiology
The smooth, dark brown, oval-shaped spores of Pseudeurotium ovale are unique compared to other members of the species.[9][10] The spore-bearing structures or asci are randomly distributed throughout the ascocarp in groups of eight.[9][10] They also range from being seven to nine microns in width, and six to eight microns in length.[9] The diameter of the fruiting body of P. ovale can be anywhere from 90 to 250 micrometers.[9] The tissue of its single layer peridium is described as being densely packed into irregular columns and rows of cells.[5][9] The cell wall of P. ovale spores are thin, growing into hyphae with no discernible septa.[10] Pseudeurotium ovale grows well below human body temperature, at around 25°C.[5] An asexual state of P. ovale has also been identified, and has been classified as sympodial.[9] The asexual spores or conidia of P. ovale form around three days after germination.[5]
Pathology
Pseudeurotium ovale has not been found to be causative in human disease. It has only ever been identified in a few cases of onychomycosis of the toe nails in elderly individuals.[11][12] Finger nails are very rarely infected by P. ovale.[12] In instances of P. ovale colonization of toenails, it was found with a dermatophyte, such as Trichophyton rubrum, or in an immunocompromised individual.[11] The nail appearance was severely altered, presenting with discolouration, and had lost their structural integrity.[11] In one infection, the dermatophyte Trichophyton rubrum was identified as the causative agent.[11] Pseudeurotium ovale has also been found with Cephalosporium sp. in cases of onychomycosis; however their role in disease was unclear.[11]
Medical applications
Some toxins produced by Pseudeurotium ovale have been found to have antimicrobial effects, and can act ton the immune response, dampening it in some cases.[13][14] Ovalicin is a secondary metabolite, produced by the mycelium. Its main component is β-trans-bergamotene, a volatile organic compound in sesquiterpene class.[13][14] Environmental stressors, such as competition with other fungi or nutrient depravation, can trigger P. ovale to produce ovalicin as a response.[14] Past studies have demonstrated the potential for ovalicin as a tumour suppressing drug, as it targets methionine aminopeptidase type 2.[15] This protein is common to endothelial cells and is necessary for the formation of new blood vessels, which allow tumour growth.[15] β-trans-begamotene is also produced by Aspergillus fumigatus.[14]
References
- ↑ Doveri, Francesco; Sarrocco, Sabrina; Vannacci, Giovanni (April–June 2013). "Studies on three rare coprophilous plectomycetes from Italy". Mycotaxon. 124: 279–300 – via Mycotaxon.
- ↑ "Pseudeorotium ovale". http://www.mycobank.org/BioloMICS.aspx?TableKey=14682616000000067&Rec=22964&Fields=All. Retrieved 26 October 2019.
- ↑ "Pseudeurotium ovale". https://www.gbif.org/search?q=pseudeurotium%20ovale. Retrieved 20 November 2019.
- ↑ "Pseudeurotium ovale". https://www.gbif.org/search?q=pseudeurotium%20ovale. Retrieved 20 November 2019.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 Stolk, Amelia (9 April 1954). "The genera Anixiopsis Hansen and Pseudeurotium Van Beyma". Antonie van Leeuwenhoek 1 (21): 65–79. doi:10.1007/BF02543800. PMID 14350602.
- ↑ 6.0 6.1 6.2 Sogonov, M.V.; Schroers, H.J.; Gams, W.; Dijksterhuis, J.; Summerbell, R.C. (March 2005). "The hyphomcete Teberdinia hygrophila gen. nov., sp. nov. and related anamorphs of Pseudeurotium species". Mycologia. 97 (3): 695–709 – via Taylor and Francis Online.
- ↑ Dennis, R.W.G. (1968). British Ascomycetes. Lehre, Germany: Verlag Von J. Cramer. p. 337-342.
- ↑ "Occurrences". https://www.gbif.org/occurrence/search?offset=0&q=pseduerotium%20ovale.
- ↑ 9.00 9.01 9.02 9.03 9.04 9.05 9.06 9.07 9.08 9.09 9.10 9.11 Doveri, Francesco; Sarrocco, Sabrina; Vannacci, Giovanni (Spring 2013). "Studies on three rare coprophilous plectomycetes from Italy". Mycotaxon 124: 279–300. doi:10.5248/124.279. https://www.researchgate.net/publication/248387031.
- ↑ 10.0 10.1 10.2 10.3 Ellis, Martin B.; Ellis, J. Pamela (1988). Microfungi on miscellaneous substrates: an identification handbook. Portland OR, USA: Timber Press. p. 136. ISBN:0-88192-115-7.
- ↑ 11.0 11.1 11.2 11.3 11.4 English, M. P.; Harman, R. R. M.; Turvey, J. W. J. (1966). Pseudeurotium Ovalis in Toenails. London: Chelsea School of Chiropody. pp. 553–556.
- ↑ 12.0 12.1 Griffiths, Christopher; Barker, Jonathan; Bleiker, Tanya; Chalmers, Robert; Creamer, Daniel (2016). Rook's Textbook of Dermatology, 4 Volume Set. 4 (9 ed.). UK: John Wiley & Sons. pp. 56. ISBN 9781118441190. https://books.google.com/books?id=85AvCgAAQBAJ&q=pseudeurotium+ovale+onychomycosis&pg=RA2-PA56.
- ↑ 13.0 13.1 Cane, David; King, G. (9 September 1976). "The Biosynthesis of Ovalicin: Isolation of B-trans-Bergamotene". Tetrahedron Letters 51: 4737–4740. doi:10.1016/S0040-4039(00)93013-2.
- ↑ 14.0 14.1 14.2 14.3 Kramer, Rolf; Abraham, Wolf-Rainer (2012). "Volatile sesquiterpenes from fungi: what are they good for?". Phytochem Rev 11: 15–37. doi:10.1007/s11101-011-9216-2.
- ↑ 15.0 15.1 Griffith, Eric; Su, Zhuang; Turk, Benjamin; Chen, Shaoping; Chang, Yie-Hwa; Wu, Zhuchun; Biemann, Klaus; Liu, Jun (1997). "Methionine aminopeptidase (type 2) is the common target for angiogenesis inhibitors AGM-1470 and ovalicin". Chemistry and Biology 4 (6): 461–471. doi:10.1016/S1074-5521(97)90198-8. PMID 9224570.
Wikidata ☰ Q10642169 entry
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