{{Short description|Genus of fungi}} {{Automatic taxobox | image = Aspergillus niger 01.jpg | image_caption = Conidial head of ''Aspergillus niger'' | taxon = Aspergillus | authority = Micheli ex Haller (1768) | subdivision_ranks = Species | subdivision = See List of ''Aspergillus'' species | synonyms_ref = <ref name="Species Fungorum synonymy"/> | synonyms = {{Collapsible list|bullets=yes |''Acmosporium'' {{au|Corda (1839)}} |''Alliospora'' {{au|Pim (1883)}} |''Aspergillopsis'' {{au|Speg. (1910)}} |''Aspergillus'' {{au|P.Micheli (1729)}} |''Basidiella'' {{au|Cooke (1878)}} |''Briarea'' {{au|Corda (1831)}} |''Chaetosartorya'' {{au|Subram. (1972)}} |''Cladaspergillus'' {{au|Ritgen (1831)}} |''Cladosarum'' {{au|E.Yuill & J.L.Yuill (1938)}} |''Cleistosoma'' {{au|Harkn. (1884)}} |''Clistosoma'' {{au|Clem. & Shear (1931)}} |''Cristaspora'' {{au|Fort & Guarro (1984)}} |''Dichotomomyces'' {{au|Saito (1949)}} |''Dichotomomyces'' {{au|Saito ex D.B.Scott (1970)}} |''Diplostephanus'' {{au|Langeron (1922)}} |''Edyuillia'' {{au|Subram. (1972)}} |''Emericella'' {{au|Berk. (1857)}} |''Euaspergillus'' {{au|F.Ludw. (1892)}} |''Eurotium'' {{au|Link (1809)}} |''Fennellia'' {{au|B.J.Wiley & E.G.Simmons (1973)}} |''Gutturomyces'' {{au|Rivolta (1873)}} |''Gymnoeurotium'' {{au|Malloch & Cain (1973)}} |''Harpezomyces'' {{au|Malloch & Cain (1973)}} |''Hemisartorya'' {{au|J.N.Rai & H.J.Chowdhery (1976)}} |''Inzengaea'' {{au|Borzí (1885)}} |''Neosartorya'' {{au|Malloch & Cain (1973)}} |''Otomyces'' {{au|Wreden (1874)}} |''Petromyces'' {{au|Malloch & Cain (1973)}} |''Phialosimplex'' {{au|Sigler (2010)}} |''Polypaecilum'' {{au|G.Sm. (1961)}} |''Pyrobolus'' {{au|Kuntze (1891)}} |''Raperia'' {{au|Subram. & Rajendran (1976)}} |''Redaellia'' {{au|Cif. (1930)}} |''Rhodocephalus'' {{au|Corda (1837)}} |''Rhopalocystis'' {{au|Grove (1911)}} |''Royella'' {{au|R.S.Dwivedi (1960)}} |''Saitoa'' {{au|Rajendran & Muthappa (1980)}} |''Sartorya'' {{au|Vuill. (1927)}} |''Sceptromyces'' {{au|Corda (1831)}} |''Sporophormis'' {{au|Malloch & Cain (1973)}} |''Sterigmatocystis'' {{au|C.E.Cramer (1859)}} |''Stilbothamnium'' {{au|Henn. (1897)}} |''Syncleistostroma'' {{au|Subram. (1972)}} |''Theclospora'' {{au|Harkn. (1884)}} |''Warcupiella'' {{au|Subram. (1972)}} }} }} '''''<span lang="hindi" dir="ltr">Aspergillus</span>''''' ({{IPAc-en|ˌ|æ|s|p|ər|ˈ|dʒ|ɪ|l|ə|s}}) is a genus consisting of several hundred mold species found in various climates worldwide.
''Aspergillus'' was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli. Viewing the fungi under a microscope, Micheli was reminded of the shape of an ''aspergillum'' (holy water sprinkler), from Latin ''spargere'' (to sprinkle), and named the genus accordingly.<ref name="Andrade_2010">{{cite journal | vauthors = Andrade-Filho Jde S, Pena GP| title = Analogies in medicine: fungus and liturgy | journal = Rev Inst Med Trop Sao Paulo | volume = 52 | issue = 5 | page = 288| date = September–October 2010 | doi =10.1590/s0036-46652010000500014 |pmid = 21049237 | doi-access = free }}</ref><ref name= Bennettjw>{{cite book |author= Bennett JW|year=2010|chapter=An Overview of the Genus ''Aspergillus''|title=''Aspergillus'': Molecular Biology and Genomics|publisher=Caister Academic Press|isbn= 978-1-904455-53-0}}</ref> Aspergillum is an asexual spore-forming structure common to all ''Aspergillus'' species; around one-third of species are also known to have a sexual stage.<ref name="MM2009">{{cite journal | vauthors = Geiser DM | title = Sexual structures in Aspergillus: morphology, importance and genomics | journal = Medical Mycology | volume = 47 | issue = Suppl 1 | pages = S21-6 | year = 2009 | pmid = 18608901 | doi = 10.1080/13693780802139859 | series = 47 }}</ref> While some species of ''Aspergillus'' are known to cause fungal infections, others are of commercial importance.
== Taxonomy == === Species === {{main|List of Aspergillus species}}
In March 2010, ''Aspergillus'' covered 837 species of fungi.<ref>{{cite journal | vauthors = Hawksworth DL | title = Naming Aspergillus species: progress towards one name for each species | journal = Medical Mycology | volume = 49 Suppl 1 | issue = S1 | pages = S70-6 | date = April 2011 | pmid = 20718610 | doi = 10.3109/13693786.2010.504753 | doi-access = free }}</ref> Notable species placed in Aspergillus include: * ''Aspergillus flavus'' is a notable plant pathogen impacting crop yields and a common cause of aspergillosis. * ''Aspergillus fumigatus'' is the most common cause of aspergillosis in individuals with an immunodeficiency. * ''Aspergillus nidulans'' has seen heavy use as research organism in cell biology. * ''Aspergillus niger'' is used in the chemical industry for a variety of applications, while also being a known food contaminant and a possible pathogen to humans. * ''Aspergillus oryzae'' and ''A. sojae'' are used in East Asian cuisine in the production of ''sake'', soy sauce and other fermented food products. * ''Aspergillus terreus'' is used in the production of organic acids but can also cause opportunistic infections in humans.
===Inner taxonomy=== The expansive genus ''Aspergillosis'' is currently divided into six subgenera of which many are further split into a total of 27 sections.<ref name=Houbraken2020>{{cite journal |vauthors=Houbraken J, Kocsubé S, Visagie CM, Yulmaz N, Wang XC, Meijer M, Kraak B, Hubka V, Bensch K, Samson RA, Frisvad JC |title=Classification of ''Aspergillus'', ''Penicillium'', ''Talaromyces'' and related genera (''Eurotiales''): An overview of families, genera, subgenera, sections, series and species |journal=Studies in Mycology |year=2020 |volume=95 |pages=5–169 |doi= 10.1016/j.simyco.2020.05.002|pmid=32855739 |pmc=7426331 }}</ref> * Subgenus ''Circumdati'', divided in 10 sections. Linked to former teleomorphic genera ''Petromyces'', ''Neopetromyces'' and ''Fennellia''. * Subgenus ''Nidulantes'', divided in 9 sections. Linked to former teleomorphic genus ''Emericella''. * Subgenus ''Fumigati'', divided in 4 sections. Linked to former teleomorphic genus ''Neocarpenteles'', ''Neosartorya'' and ''Dichotomomyces''. * Subgenus ''Aspergillus'', divided in 2 sections. Linked to former teleomorphic genus ''Eurotium''. * Subgenus and section ''Cremei''. Linked to former teleomorphic genus ''Chaetosartorya'' and ''Cristaspora'' * Subgenus and section ''Polypaecilum''. Includes former genera ''Polypaecilum'' and ''Phialosimplex''.
The linkage to former teleomorphic genera derive from Samson ''et al.'' (2014).<ref name=Samson2014>{{Cite journal |last1=Samson |first1=RA |last2=Visagie |first2=CM |last3=Houbraken |first3=J |last4=Hong |first4=SB |last5=Hubka |first5=V |last6=Klaassen |first6=CHW |last7=Perrone |first7=G |last8=Seifert |first8=KA |last9=Susca |first9=A |last10=Tanney |first10=JB |last11=Varga|first11=J|last12=Kocsubé|first12=S|last13=Szigeti|first13=G|last14=Yaguchi|first14=T|last15=Frisvad|first15=JC|date=June 2014 |title=Phylogeny, identification and nomenclature of the genus ''Aspergillus'' |journal=Studies in Mycology |volume=78 |pages=141–173 |doi=10.1016/j.simyco.2014.07.004|doi-access=free |pmid=25492982 |pmc=4260807 }}</ref> The current division is based on Houbracken ''et al.'' (2020), which also notes that the former teleomorphic genera are now understood as morphotypes: eurotium-type, neosartorya-type, emericella-type, petromyces-type, chaetosartorya-type, fennellia-type and neopetromyces-type.<ref name=Houbraken2020/>
== Growth and distribution == ''Aspergillus'' is defined as a group of conidial fungi—that is, fungi in an asexual state. Some of them, however, are known to have a teleomorph (sexual state) in the Ascomycota. With DNA evidence, all members of the genus ''Aspergillus'' are members of the phylum Ascomycota.{{cn|date=November 2023}}
Members of the genus possess the ability to grow where a high osmotic pressure exists (high concentration of sugar, salt, etc.). ''Aspergillus'' species are highly aerobic and are found in almost all oxygen-rich environments, where they commonly grow as molds on the surface of a substrate, as a result of the high oxygen tension. Commonly, fungi grow on carbon-rich substrates like monosaccharides (such as glucose) and polysaccharides (such as amylose). ''Aspergillus'' species are common post-harvest contaminants of starchy foods (such as bread and potatoes), and grow in or on many plants and trees.<ref>{{Cite journal| doi = 10.2298/ZMSPN1324013K| issn = 0352-4906| eissn = 2406-0828| issue = 124| pages = 13–25| last1 = Kocube| first1 = Sandor| last2 = Varga| first2 = Janos| last3 = Sigeti| first3 = Djendji| last4 = Baranji| first4 = Nikolet| last5 = Suri| first5 = Katalin| last6 = Tot| first6 = Bela| last7 = Toldi| first7 = Eva| last8 = Bartok| first8 = Tibor| last9 = Mesterhazi| first9 = Akos| title = Aspergillus species as mycotoxin producers in agricultural products in central Europe| journal = Zbornik Matice srpske za prirodne nauke| access-date = 2026-01-10| date = 2013| url = https://doiserbia.nb.rs/Article.aspx?ID=0352-49061324013K| doi-access = free}}</ref>
In addition to growth on carbon sources, many species of ''Aspergillus'' demonstrate oligotrophy where they are capable of growing in nutrient-depleted environments, or environments with a complete lack of key nutrients. ''Aspergillus niger'' is a prime example of this; it can be found growing on damp walls, as a major component of mildew.{{cn|date=November 2023}}
Several species of ''Aspergillus'', including ''A. niger'' and ''A. fumigatus'', will readily colonise buildings,<ref>{{cite journal | vauthors = Latgé JP | title = Aspergillus fumigatus and aspergillosis | journal = Clinical Microbiology Reviews | volume = 12 | issue = 2 | pages = 310–50 | date = April 1999 | pmid = 10194462 | pmc = 88920 | doi = 10.1128/CMR.12.2.310 }}</ref> favouring warm and damp or humid areas such as bathrooms and around window frames.<ref>{{cite web |title=What are fungal spores? |url=https://www.worcester.ac.uk/about/academic-schools/school-of-science-and-the-environment/science-and-the-environment-research/national-pollen-and-aerobiology-research-unit/What-are-fungal-spores.aspx |website=University of Worcester |access-date=6 August 2019}}</ref>
''Aspergillus'' are found in millions of pillows.<ref>{{cite web |url=https://www.sciencedaily.com/releases/2005/10/051015093046.htm |title=Pillows: A Hot Bed Of Fungal Spores |website=Science Daily |access-date=2017-05-08 |archive-url=https://web.archive.org/web/20171008030314/https://www.sciencedaily.com/releases/2005/10/051015093046.htm |archive-date=2017-10-08 |url-status=live }}</ref>
== Commercial importance == [[Image:Ascomycetes.jpg|thumb|left|250px|Various ''Penicillium'', ''Aspergillus'' spp. and other fungi growing in axenic culture]] [[File:Modell von Aspergillus (Gießkannenschimmel) -Osterloh- -Brendel 10f-.jpg|thumb|left|250px|Historical model of ''Aspergillus'', Botanical Museum Greifswald]] Species of ''Aspergillus'' are important medically and commercially. Some species can cause infection in humans and other animals. Some infections found in animals have been studied for years, while other species found in animals have been described as new and specific to the investigated disease, and others have been known as names already in use for organisms such as saprophytes. More than 60 ''Aspergillus'' species are medically relevant pathogens.<ref name=thom>{{cite book| vauthors = Thom C, Church M |title=The Aspergilli|location=Baltimore|publisher=The Williams & Wilkins Company|year=1926}}</ref> For humans, a range of diseases such as infection to the external ear,<ref name="Ear infection">{{cite journal |last1=Rob |first1=Filip |last2=Školoudík |first2=Lukáš |last3=Chrobok |first3=Viktor |last4=Dědková |first4=Jana |last5=Kašparová |first5=Petra |last6=Podrazilová |first6=Lucie |title=Invasive Aspergillus infection of middle ear in a patient treated with secukinumab, methotrexate, and corticosteroids for psoriasis and psoriatic arthritis |journal=Journal of Dermatological Treatment |date=3 October 2022 |volume=33 |issue=7 |pages=3063–3065 |doi=10.1080/09546634.2022.2104442 |pmid=35856655 |publisher=University Hospital Hradec Králové |location=Prague, Czech Republic |language=Czech}}</ref> pulmonary disease,<ref name="pulmonary disease">{{cite journal |last1=Guo |first1=Liang |last2=Wu |first2=Xiulin |last3=Wu |first3=Xueling |title=Aspergillus infection in chronic obstructive pulmonary diseases |journal=The Clinical Respiratory Journal |date=March 2023 |volume=17 |issue=3 |pages=129–138 |doi=10.1111/crj.13585 |pmid=36710403 |publisher=Institute of Respiratory Disease, Chinese Army Medical University |location=Chongqing, China |language=zh |pmc=9978918}}</ref> skin lesions, and ulcers classed as mycetomas are found.<ref name="Skin lesions">{{cite journal |last1=Warad |first1=Basavraj |last2=Bhoyar |first2=Abhiram |last3=Gavkare |first3=Ajay |last4=Kanthikar |first4=Shivraj |last5=Nagoba |first5=Basavraj |title=Primary cutaneous ulcer caused by Aspergillus species following direct inoculation through ECG lead adhesive |journal=Journal of Infection and Public Health |date=June 2021 |volume=14 |issue=6 |pages=772–774 |doi=10.1016/j.jiph.2021.03.011 |pmid=34022736 |doi-access=free }}</ref><ref name="Epidemiology">{{cite journal |last1=Cadena |first1=Jose |last2=Thompson |first2=George R. |last3=Patterson |first3=Thomas F. |title=Aspergillosis: Epidemiology, Diagnosis, and Treatment |journal=Infectious Disease Clinics of North America |date=June 2021 |volume=35 |issue=2 |pages=415–434 |doi=10.1016/j.idc.2021.03.008 |pmid=34016284 |publisher=University of Texas Health Science Center at San Antonio}}</ref>
Other species are important in commercial microbial fermentations. For example, alcoholic beverages such as Japanese ''sake'' are often made from rice or other starchy ingredients (like manioc), rather than from grapes or malted barley. Typical microorganisms used to make alcohol, such as yeasts of the genus ''Saccharomyces'', cannot ferment these starches. Therefore, ''koji'' mold such as ''Aspergillus oryzae'' is used to first break down the starches into simpler sugars.<ref>{{cite web |vauthors = Spiegel A |website=The Huffington Post |quote=...to make soy sauce, first you add aspergillus mold to the soy beans and grains to produce a mixture called koji. |date=April 8, 2014 |title=Are You Using The Right Soy Sauce? Here's How To Find Out |url=http://www.huffingtonpost.com/2014/04/08/soy-sauce_n_5105861.html |access-date=2017-07-29 |archive-url=https://web.archive.org/web/20170806131816/http://www.huffingtonpost.com/2014/04/08/soy-sauce_n_5105861.html |archive-date=2017-08-06 |url-status=live }}</ref>
Members of the genus are also sources of natural products that can be used in the development of medications to treat human disease.<ref>{{Cite patent|country=US|number=6069146|pubdate=2000-05-30|title=Halimide, a cytotoxic marine natural product, and derivatives thereof|assign1=The Regents of the University of California|inventor1-last=Fenical|inventor1-first=William|inventor2-last=Jensen|inventor2-first=Paul R.|inventor3-last=Cheng|inventor3-first=Xing C.}}</ref> ''Aspergillus'' spp. are known to produce anthraquinone which has commercial importance due to its antibacterial and antifungal properties.<ref>{{Cite journal|last1=Toma|first1=Maria Afroz|last2=Nazir|first2=K. H. M. Nazmul Hussain|last3=Mahmud|first3=Md Muket|last4=Mishra|first4=Pravin|last5=Ali|first5=Md Kowser|last6=Kabir|first6=Ajran|last7=Shahid|first7=Md Ahosanul Haque|last8=Siddique|first8=Mahbubul Pratik|last9=Alim|first9=Md Abdul|title=Isolation and Identification of Natural Colorant Producing Soil-Borne Aspergillus niger from Bangladesh and Extraction of the Pigment|journal=Foods|year=2021|language=en|volume=10|issue=6|page=1280|doi=10.3390/foods10061280|pmid=34205202|pmc=8227025|doi-access=free}}</ref>
Perhaps the largest application of ''Aspergillus niger'' is as the major source of citric acid;<ref name="Citric Acid">{{cite journal |last1=Behera |first1=Bikash Chandra |title=Citric acid from Aspergillus niger: a comprehensive overview |journal=Critical Reviews in Microbiology |date=1 November 2020 |volume=46 |issue=6 |pages=727–749 |doi=10.1080/1040841X.2020.1828815 |pmid=33044884 }}</ref> this organism accounts for over 90% of global citric acid production,<ref name="Citric Acid Production">{{cite journal |last1=Medeiros |first1=Alexandre D'Lamare Maia de |last2=Medeiros |first2=Thiago Pettrus Maia de |title=Citric acid production by Aspergillus spp. through submerged fermentation using different production mediums containing agroindustrial residues |journal=Research, Society and Development |date=20 April 2022 |volume=11 |issue=6 |pages=e8011628839 |doi=10.33448/rsd-v11i6.28839 |url=https://rsdjournal.org/index.php/rsd/article/view/28839 |access-date=23 August 2025 |publisher=Journal Metrics |location=Pernambuco, Brazil |language=Portuguese |issn=2525-3409|doi-access=free }}</ref> equaling more than 2.54 million metric tonnes (2.8 million US tons) per year.<ref name="Citric Acid Quantity">{{cite journal |last1=Książek |first1=Ewelina |title=Citric Acid: Properties, Microbial Production, and Applications in Industries |journal=Molecules |date=19 December 2023 |volume=29 |issue=1 |page=22 |doi=10.3390/molecules29010022 |pmid=38202605 |publisher=Department of Agroenginieering and Quality Analysis, Faculty of Production Engineering, Wroclaw University of Economics and Business |location=Wrocław, Poland |doi-access=free |language=Polish |pmc=10779990}}</ref> ''A. niger'' is also commonly used for the production of native and foreign enzymes, including glucose oxidase, <!-- really?hen egg white --> lysozyme, and lactase.<ref>{{cite web |title=GRAS Notification for Acid Lactase from ''Aspergillus oryzae'' Expressed in ''Aspergillus niger'' |website=Food and Drug Administration |url=https://www.fda.gov/downloads/Food/IngredientsPackagingLabeling/GRAS/NoticeInventory/UCM400718 |access-date=2016-03-17 |archive-url=https://web.archive.org/web/20160323100548/https://www.fda.gov/downloads/Food/IngredientsPackagingLabeling/GRAS/NoticeInventory/UCM400718 |archive-date=2016-03-23 }} Section 2.</ref> In these instances, the culture is rarely grown on a solid substrate, although this is still common practice in Japan, but is more often grown as a submerged culture in a bioreactor. In this way, the most important parameters can be strictly controlled, and maximal productivity can be achieved. This process also makes it far easier to separate the chemical or enzyme of importance from the medium, and is therefore far more cost-effective.
== Research == [[Image:Four 3-day old Aspergillus colonies on a Petri dish.png|thumb|right|Four three-day-old ''Aspergillus'' colonies. Clockwise from top-left: an ''A. nidulans'' laboratory strain; a similar strain with a mutation in the yA marker gene involved in green pigmentation; an ''A. oryzae'' strain used in soy fermentation; ''A. oryzae'' RIB40]]
[[File:Aspergillus 235 mags 3X3 copy.jpeg|thumb|right|A scan of ''Aspergillus'' taken at 235 magnifications under a scanning electron microscope]]
''A. nidulans'' (''Emericella nidulans'') has been used as a research organism for many years and was used by Guido Pontecorvo to demonstrate parasexuality in fungi. Recently, ''A. nidulans'' was one of the pioneering organisms to have its genome sequenced by researchers at the Broad Institute. As of 2008, a further seven ''Aspergillus'' species have had their genomes sequenced: the industrially useful ''A. niger'' (two strains), ''A. oryzae'', and ''A. terreus'', and the pathogens ''A. clavatus'', ''A. fischerianus'' (''Neosartorya fischeri''), ''A. flavus'', and ''A. fumigatus'' (two strains).<ref>{{cite journal | vauthors = Wortman JR, Gilsenan JM, Joardar V, Deegan J, Clutterbuck J, Andersen MR, Archer D, Bencina M, Braus G, Coutinho P, von Döhren H, Doonan J, Driessen AJ, Durek P, Espeso E, Fekete E, Flipphi M, Estrada CG, Geysens S, Goldman G, de Groot PW, Hansen K, Harris SD, Heinekamp T, Helmstaedt K, Henrissat B, Hofmann G, Homan T, Horio T, Horiuchi H, James S, Jones M, Karaffa L, Karányi Z, Kato M, Keller N, Kelly DE, Kiel JA, Kim JM, van der Klei IJ, Klis FM, Kovalchuk A, Krasevec N, Kubicek CP, Liu B, Maccabe A, Meyer V, Mirabito P, Miskei M, Mos M, Mullins J, Nelson DR, Nielsen J, Oakley BR, Osmani SA, Pakula T, Paszewski A, Paulsen I, Pilsyk S, Pócsi I, Punt PJ, Ram AF, Ren Q, Robellet X, Robson G, Seiboth B, van Solingen P, Specht T, Sun J, Taheri-Talesh N, Takeshita N, Ussery D, vanKuyk PA, Visser H, van de Vondervoort PJ, de Vries RP, Walton J, Xiang X, Xiong Y, Zeng AP, Brandt BW, Cornell MJ, van den Hondel CA, Visser J, Oliver SG, Turner G | display-authors = 6 | title = The 2008 update of the Aspergillus nidulans genome annotation: a community effort | journal = Fungal Genetics and Biology | volume = 46 Suppl 1 | issue = 1 | pages = S2-13 | date = March 2009 | pmid = 19146970 | pmc = 2826280 | doi = 10.1016/j.fgb.2008.12.003 | series = 46 }}</ref> ''A. fischerianus'' is hardly ever pathogenic, but is very closely related to the common pathogen ''A. fumigatus''; it was sequenced in part to better understand ''A. fumigatus'' pathogenicity.<ref>{{cite web |url=http://www.broadinstitute.org/annotation/genome/aspergillus_group/GenomeDescriptions.html |title=Descriptions – Aspergillus Comparative |publisher=Broad Institute |access-date=2009-10-15 |archive-url=https://web.archive.org/web/20091122052538/http://www.broadinstitute.org/annotation/genome/aspergillus_group/GenomeDescriptions.html |archive-date= 22 November 2009 |url-status=live}} </ref>
===Sexual reproduction=== Of the 250 species of aspergilli, about 64% have no known sexual state.<ref name=Dyer>{{cite journal | vauthors = Dyer PS, O'Gorman CM | title = A fungal sexual revolution: Aspergillus and Penicillium show the way | journal = Current Opinion in Microbiology | volume = 14 | issue = 6 | pages = 649–54 | date = December 2011 | pmid = 22032932 | doi = 10.1016/j.mib.2011.10.001 }}</ref> However, many of these species likely have an as yet unidentified sexual stage.<ref name=Dyer /> Sexual reproduction occurs in two fundamentally different ways in fungi. These are outcrossing (in heterothallic fungi) in which two different individuals contribute nuclei, and self-fertilization or selfing (in homothallic fungi) in which both nuclei are derived from the same individual. In recent years, sexual cycles have been discovered in numerous species previously thought to be asexual. These discoveries reflect recent experimental focus on species of particular relevance to humans.{{cn|date=November 2023}}
''A. fumigatus'' is the most common species to cause disease in immunodeficient humans. In 2009, ''A. fumigatus'' was shown to have a heterothallic, fully functional sexual cycle.<ref name="pmid19043401">{{cite journal | vauthors = O'Gorman CM, Fuller H, Dyer PS | title = Discovery of a sexual cycle in the opportunistic fungal pathogen Aspergillus fumigatus | journal = Nature | volume = 457 | issue = 7228 | pages = 471–4 | date = January 2009 | pmid = 19043401 | doi = 10.1038/nature07528 | bibcode = 2009Natur.457..471O | s2cid = 4371721 }}</ref> Isolates of complementary mating types are required for sex to occur.
''A. flavus'' is the major producer of carcinogenic aflatoxins in crops worldwide. It is also an opportunistic human and animal pathogen, causing aspergillosis in immunocompromised individuals. In 2009, a sexual state of this heterothallic fungus was found to arise when strains of opposite mating types were cultured together under appropriate conditions.<ref name="pmid19537215">{{cite journal | vauthors = Horn BW, Moore GG, Carbone I | title = Sexual reproduction in Aspergillus flavus | journal = Mycologia | volume = 101 | issue = 3 | pages = 423–9 | year = 2009 | pmid = 19537215 | doi = 10.3852/09-011 | s2cid = 20648447 | url = http://www.mycologia.org/cgi/pmidlookup?view=short&pmid=19537215 | url-access = subscription }}</ref>
''A. lentulus'' is an opportunistic human pathogen that causes invasive aspergillosis with high mortality rates. In 2013, ''A. lentulus'' was found to have a heterothallic functional sexual breeding system.<ref name="pmid23650087">{{cite journal | vauthors = Swilaiman SS, O'Gorman CM, Balajee SA, Dyer PS | title = Discovery of a sexual cycle in Aspergillus lentulus, a close relative of A. fumigatus | journal = Eukaryotic Cell | volume = 12 | issue = 7 | pages = 962–9 | date = July 2013 | pmid = 23650087 | pmc = 3697472 | doi = 10.1128/EC.00040-13 }}</ref>
''A. terreus'' is commonly used in industry to produce important organic acids and enzymes, and was the initial source for the cholesterol-lowering drug lovastatin. In 2013, ''A. terreus'' was found to be capable of sexual reproduction when strains of opposite mating types were crossed under appropriate culture conditions.<ref name="pmid23074177">{{cite journal | vauthors = Arabatzis M, Velegraki A | title = Sexual reproduction in the opportunistic human pathogen Aspergillus terreus | journal = Mycologia | volume = 105 | issue = 1 | pages = 71–9 | year = 2013 | pmid = 23074177 | doi = 10.3852/11-426 | s2cid = 9584227 | url = http://www.mycologia.org/cgi/pmidlookup?view=short&pmid=23074177 | url-access = subscription }}</ref>
These findings with ''Aspergillus'' species are consistent with accumulating evidence, from studies of other eukaryotic species, that sex was likely present in the common ancestor of all eukaryotes.<ref name="pmid18663385">{{cite journal | vauthors = Malik SB, Pightling AW, Stefaniak LM, Schurko AM, Logsdon JM | title = An expanded inventory of conserved meiotic genes provides evidence for sex in Trichomonas vaginalis | journal = PLOS ONE | volume = 3 | issue = 8 | article-number = e2879 | date = August 2007 | pmid = 18663385 | pmc = 2488364 | doi = 10.1371/journal.pone.0002879 | bibcode = 2008PLoSO...3.2879M | doi-access = free }}</ref><ref name="pmid23099518">{{cite journal | vauthors = Heitman J, Sun S, James TY | title = Evolution of fungal sexual reproduction | journal = Mycologia | volume = 105 | issue = 1 | pages = 1–27 | year = 2013 | pmid = 23099518 | doi = 10.3852/12-253 | s2cid = 18167947 | url = http://www.mycologia.org/cgi/pmidlookup?view=short&pmid=23099518 | url-access = subscription }}</ref>
''A. nidulans'', a homothallic fungus, is capable of self-fertilization. Selfing involves activation of the same mating pathways characteristic of sex in outcrossing species, i.e. self-fertilization does not bypass required pathways for outcrossing sex, but instead requires activation of these pathways within a single individual.<ref name="pmid17669651">{{cite journal | vauthors = Paoletti M, Seymour FA, Alcocer MJ, Kaur N, Calvo AM, Archer DB, Dyer PS | title = Mating type and the genetic basis of self-fertility in the model fungus Aspergillus nidulans | journal = Current Biology | volume = 17 | issue = 16 | pages = 1384–9 | date = August 2007 | pmid = 17669651 | doi = 10.1016/j.cub.2007.07.012 | s2cid = 17068935 | doi-access = free | bibcode = 2007CBio...17.1384P }}</ref>
Among those ''Aspergillus'' species that exhibit a sexual cycle, the overwhelming majority in nature are homothallic (self-fertilizing).<ref name="pmid22091779">{{cite journal | vauthors = Dyer PS, O'Gorman CM | title = Sexual development and cryptic sexuality in fungi: insights from Aspergillus species | journal = FEMS Microbiology Reviews | volume = 36 | issue = 1 | pages = 165–92 | date = January 2012 | pmid = 22091779 | doi = 10.1111/j.1574-6976.2011.00308.x | doi-access = free }}</ref> This observation suggests ''Aspergillus'' species can generally maintain sex though little genetic variability is produced by homothallic self-fertilization. ''A. fumigatus'', a heterothallic (outcrossing) fungus that occurs in areas with widely different climates and environments, also displays little genetic variability either within geographic regions or on a global scale,<ref name="pmid16607012">{{cite journal | vauthors = Rydholm C, Szakacs G, Lutzoni F | title = Low genetic variation and no detectable population structure in aspergillus fumigatus compared to closely related Neosartorya species | journal = Eukaryotic Cell | volume = 5 | issue = 4 | pages = 650–7 | date = April 2006 | pmid = 16607012 | pmc = 1459663 | doi = 10.1128/EC.5.4.650-657.2006 }}</ref> again suggesting sex, in this case outcrossing sex, can be maintained even when little genetic variability is produced.
=== Genomics === The simultaneous publication of three ''Aspergillus'' genome manuscripts in ''Nature'' in December 2005 established the genus as the leading filamentous fungal genus for comparative genomic studies. Like most major genome projects, these efforts were collaborations between a large sequencing centre and the respective community of scientists. For example, the Institute for Genome Research (TIGR) worked with the ''A. fumigatus'' community. ''A. nidulans'' was sequenced at the Broad Institute. ''A. oryzae'' was sequenced in Japan at the National Institute of Advanced Industrial Science and Technology. The Joint Genome Institute of the Department of Energy has released sequence data for a citric acid-producing strain of ''A. niger''. TIGR, now renamed the J. Craig Venter Institute, is currently spearheading a project on the ''A. flavus'' genome.<ref name= MachidaMGomiK>{{cite book | veditors = Machida M, Gomi K | year=2010 |title=''Aspergillus'': Molecular Biology and Genomics | publisher=Caister Academic Press | isbn= 978-1-904455-53-0}}</ref>
''Aspergillus'' is characterized by high levels of genetic diversity and, using protostome divergence as a scale, is as diverse as the Vertebrates phylum although both inter and intra-specific genome structure is relatively plastic.<ref>{{cite journal | vauthors = Gibbons JG, Rokas A | title = The function and evolution of the Aspergillus genome | journal = Trends in Microbiology | volume = 21 | issue = 1 | pages = 14–22 | date = January 2013 | pmid = 23084572 | pmc = 3534798 | doi = 10.1016/j.tim.2012.09.005 | url = }}</ref> The genomes of some ''Aspergillus'' species, such as ''A. flavus'' and ''A. oryzae'', are more rich and around 20% larger than others, such as ''A. nidulans'' and ''A. fumigatus''. Several mechanisms could explain this difference, although the combination of segmental duplication, genome duplication, and horizontal gene transfer acting in a piecemeal fashion is well-supported.<ref>{{cite journal | vauthors = Khaldi N, Wolfe KH | title = Elusive origins of the extra genes in Aspergillus oryzae | journal = PLOS ONE | volume = 3 | issue = 8 | article-number = e3036 | date = August 2008 | pmid = 18725939 | pmc = 2515630 | doi = 10.1371/journal.pone.0003036 | bibcode = 2008PLoSO...3.3036K | veditors = Gadagkar S | doi-access = free }}</ref>
Genome sizes for sequenced species of ''Aspergillus'' range from about 29.3 Mb for ''A. fumigatus'' to 37.1 Mb for ''A. oryzae'', while the numbers of predicted genes vary from about 9926 for ''A. fumigatus'' to about 12,071 for ''A. oryzae''. The genome size of an enzyme-producing strain of ''A. niger'' is of intermediate size at 33.9 Mb.<ref name="Bennettjw" />
== Pathogens == Some ''Aspergillus'' species cause serious disease in humans and animals. The most common pathogenic species are ''A. fumigatus'' and ''A. flavus'', which produces aflatoxin which is both a toxin and a carcinogen, and which can contaminate foods such as nuts. The most common species causing allergic disease are ''A. fumigatus'' and ''A. clavatus''. Other species are important as agricultural pathogens. ''Aspergillus'' spp. cause disease on many grain crops, especially maize, and some variants synthesize mycotoxins, including aflatoxin. ''Aspergillus'' can cause neonatal infections.<ref name="Cloherty2012">{{cite book | vauthors = Cloherty J |title=Manual of neonatal care |publisher=Wolters Kluwer Health/Lippincott Williams & Wilkins |location=Philadelphia |year=2012 |isbn=978-1-60831-777-6}} Access provided by the University of Pittsburgh.</ref>
''A. fumigatus'' (the most common species) infections are primary pulmonary infections and can potentially become a rapidly necrotizing pneumonia with a potential to disseminate. The organism can be differentiated from other common mold infections based on the fact that it takes on a mold form both in the environment and in the host (unlike ''Candida albicans'' which is a dimorphic mold in the environment and a yeast in the body).{{cn|date=November 2023}}
== Aspergillosis == {{Main|Aspergillosis}} right|thumb|Pulmonary aspergillosis Aspergillosis is the group of diseases caused by ''Aspergillus''. The most common species among paranasal sinus infections associated with aspergillosis is ''A. fumigatus''.<ref name=boz>{{cite journal | vauthors = Bozkurt MK, Ozçelik T, Saydam L, Kutluay L | title = [A case of isolated aspergillosis of the maxillary sinus] | language = tr | journal = Kulak Burun Bogaz Ihtisas Dergisi | volume = 18 | issue = 1 | pages = 53–5 | date = 2008 | pmid = 18443405 }}</ref> The symptoms include fever, cough, chest pain, or breathlessness, which also occur in many other illnesses, so diagnosis can be difficult. Usually, only patients with already weakened immune systems or who suffer other lung conditions are susceptible.{{cn|date=November 2023}}
In humans, the major forms of disease are:<ref>{{cite web |url=http://emedicine.medscape.com/article/296052-overview |title=Aspergillosis |publisher=MedScape |access-date=2014-06-29 |archive-url=https://web.archive.org/web/20140223073734/http://emedicine.medscape.com/article/296052-overview |archive-date=2014-02-23 |url-status=live }}</ref><ref>{{cite book | veditors = Wilson WR, Sande MA, Drew WL | title = Current diagnosis & treatment in infectious diseases. | publisher = Lange Medical Books/McGraw-Hill | date = 2001 }}</ref> * Acute invasive aspergillosis, a form that grows into surrounding tissue, more common in those with weakened immune systems such as AIDS or chemotherapy patients * Allergic bronchopulmonary aspergillosis, which affects patients with respiratory diseases such as asthma, cystic fibrosis, and sinusitis * Aspergilloma, a "fungus ball" that can form within cavities such as the lung * Disseminated invasive aspergillosis, an infection spread widely through the body
Fungal infections from Aspergillus spores remain one theory of sickness and untimely death of some early Egyptologists and tomb explorers. Ancient spores which grew on the remains of food offerings and mummies sealed in tombs and chambers may have been blown around and inhaled by the excavators, ultimately linked to the notion of the curse of the pharaohs.<ref name="pmid7800243">{{cite journal | vauthors = Di Paolo N, Guarnieri A, Garosi G, Sacchi G, Mangiarotti AM, Di Paolo M | title = Inhaled mycotoxins lead to acute renal failure | journal = Nephrology, Dialysis, Transplantation | volume = 9 | pages = 116–20 | date = 1994 | issue = Suppl 4 | pmid = 7800243 }}</ref>
Aspergillosis of the air passages is also frequently reported in birds, and certain species of ''Aspergillus'' have been known to infect insects.<ref name=thom/>
Most people inhale ''Aspergillus'' into their lungs everyday,<ref name=":0">{{Cite web |date=2021-05-10 |title=Aspergillosis {{!}} Types of Fungal Diseases {{!}} Fungal Diseases {{!}} CDC |url=https://www.cdc.gov/fungal/diseases/aspergillosis/index.html |access-date=2022-09-02 |website=www.cdc.gov |language=en-us}}</ref> but generally only the immuno-compromised become sick with aspergillosis.<ref name=":0" />
== See also == * Mold health issues * Sick building syndrome * Cryptococcus {{clear}}
== References == {{Reflist|refs=
<ref name="Species Fungorum synonymy">{{cite web |title=Synonymy. Current Name: ''Aspergillus'' P. Micheli ex Haller, Hist. stirp. Helv. (Bernae) 3: 113 (1768) |url=https://www.speciesfungorum.org/Names/SynSpecies.asp?RecordID=7248 |publisher=Species Fungorum |access-date=10 October 2023}}</ref>
}}
== Further reading == {{refbegin}} * {{Cite journal |author=Asan A. |orig-date=2004 |date=February 10, 2015 |title=Aspergillus, Penicillium, and Related Species Reported from Turkey |journal=Mycotaxon |volume=89 |issue=1 |pages=155–7 |url=http://www.mycotaxon.com/resources/checklists/asan-v89-checklist.pdf }} * {{cite journal | vauthors = Du C, Lin SK, Koutinas A, Wang R, Dorado P, Webb C | title = A wheat biorefining strategy based on solid-state fermentation for fermentative production of succinic acid | journal = Bioresource Technology | volume = 99 | issue = 17 | pages = 8310–5 | date = November 2008 | pmid = 18434138 | doi = 10.1016/j.biortech.2008.03.019 | bibcode = 2008BiTec..99.8310D }} * {{cite book | vauthors = Soltani J | date = 2016 | chapter = Secondary Metabolite Diversity of the Genus Aspergillus. | title = Recent Advances New and Future Developments in Microbial Biotechnology and Bioengineering: Aspergillus System Properties and Applications | pages = 275–292 }} * {{cite journal | vauthors = Zirbes JM, Milla CE | title = Steroid-sparing effect of omalizumab for allergic bronchopulmonary aspergillosis and cystic fibrosis | journal = Pediatric Pulmonology | volume = 43 | issue = 6 | pages = 607–10 | date = June 2008 | pmid = 18433040 | doi = 10.1002/ppul.20804 | s2cid = 25806792 }} {{refend}}
== External links == * [http://www.broad.mit.edu/annotation/genome/aspergillus_group/ Aspergillus Comparative Database] Comparative genomic resource at the Broad Institute * [https://www.ncbi.nlm.nih.gov/projects/genome/guide/aspergillus/ Aspergillus Genome Resources (NIH)] * [https://web.archive.org/web/20050512094530/http://moldacrossamerica.org/ASPPAPER%20LC.pdf ''Aspergillus'' surveillance project at a large tertiary-care hospital.] (PDF). * [http://www.cadre-genomes.org.uk/ Central Aspergillus Data Repository] * [http://fungidb.org FungiDB: An integrated functional genomics database for fungi and oomycetes] * [https://homeheavenz.com/best-air-purifier-for-mold/ Mold and Mildew] * [http://www.aspgd.org/ The Aspergillus Genome Database] {{Webarchive|url=https://web.archive.org/web/20210525180521/http://www.aspgd.org/ |date=2021-05-25 }} * [http://www.aspergillus.org.uk/ The Aspergillus/Aspergillosis Website] An encyclopedia of ''Aspergillus'' for patients, doctors and scientists * [http://www.fgsc.net/ The Fungal Genetics Stock Center] {{Webarchive|url=https://web.archive.org/web/20061001215555/http://www.fgsc.net/ |date=2006-10-01 }}
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Category:Aspergillus Category:Parasitic fungi Category:Eurotiomycetes genera Category:Taxa described in 1768