Xeromyces

Xeromyces
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Eurotiomycetes
Order: Eurotiales
Family: Aspergillaceae
Genus: Xeromyces
L.R. Fraser 1954
Species:
X. bisporus
Binomial name
Xeromyces bisporus
L.R. Fraser 1954
Synonyms[1]
  • Monascus bisporus (L.R. Fraser) Arx 1970

Xeromyces is a monotypic genus of fungus in the family Monascaceae.[2][3] Its only species, Xeromyces bisporus, was first described by L.R. Fraser in 1954.[4] No subspecies are listed in the Catalogue of Life.[2]

It is a xerophile, being able to germinate at a water activity levels between 0.62 and 0.97,[5] lower than any other known organism with the exception of Aspergillus penicillioides.[6] However, it requires a higher water activity level to produce spores.[5] It is a spoilage microbe in dry foods with high sugar contents, especially chocolate, honey, molasses, dried fruit or tobacco. Isolation of cultures requires media with 50% glucose.[7]

The estimated genome size of X. bisporus is 24.8 Mb and the fungus lacks the genes normally associated with mycotoxin production.[8]

It has unstalked cleistothecia, and each of its asci has two ascospores. Its simple asexual state consists of one or two round terminal chlamydospores.[9]

  1. ^ Arx (1970), In: Gen. Fungi Sporul. Cult. (Lehr):84
  2. ^ a b Bisby FA, Roskov YR, Orrell TM, Nicolson D, Paglinawan LE, Bailly N, Kirk PM, Bourgoin T, Baillargeon G, Ouvrard D, eds. (2011). "Species 2000 & ITIS Catalogue of Life: 2011 Annual Checklist". Species 2000: Reading, UK. Retrieved 6 October 2017.
  3. ^ Species Fungorum. Kirk P.M., 2010-11-23
  4. ^ L.R. Fraser (1954), In: Proc. Linn. Soc. N.S.W. 78:245
  5. ^ a b Pitt JI, Christian JMB (1968). "Water relations of xerophilic fungi isolated from prunes" (PDF). Applied Microbiology. 16 (12): 1853–1858.
  6. ^ Stevenson A, Hamill PG, O'kane CJ, Kminek G, Rummel JD, Voytek MA, Dijksterhuis J, Hallsworth JE (2017). "Aspergillus penicillioides differentiation and cell division at 0.585 water activity". Environmental Microbiology. 19 (2): 687–697. doi:10.1111/1462-2920.13597.
  7. ^ Pettersson OV, Su-lin LL, Lantz H, Rice T, Dijksterhuis J, Houbraken J, Samson RA, Shnürer J (2011). "Phylogeny and intraspecific variation of the extreme xerophile, Xeromyces bisporus". Fungal Biology. 115 (11): 1100–1111. doi:10.1016/j.funbio.2011.06.012. PMID 22036289.
  8. ^ Leong, Su-lin L.; Lantz, Henrik; Pettersson, Olga V.; Frisvad, Jens C.; Thrane, Ulf; Helpleper, Hermann J.; Dijksterhuls, Jan; Grabherr, Manfred; Pettersson, Mats; Tellgren-Roth, Christian; Schnürer, Johan (2015). "Genome and physiology of the ascomycete filamentous fungus Xeromyces bisporus, the most xerophilic organism isolated to date". Environmental Microbiology. 17 (2): 496–513. doi:10.1111/1462-2920.12596. PMID 25142400.
  9. ^ Jay, James M. (1998). Modern Food Microbiology (Fifth ed.). Gaithersburg, Maryland: Aspen Publishers, Inc. p. 31. ISBN 978-0-8342-1230-5.