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Brief Summary

    Aspergillus niger: Brief Summary
    provided by wikipedia

    Aspergillus niger is a fungus and one of the most common species of the genus Aspergillus.

    It causes a disease called black mould on certain fruits and vegetables such as grapes, apricots, onions, and peanuts, and is a common contaminant of food. It is ubiquitous in soil and is commonly reported from indoor environments, where its black colonies can be confused with those of Stachybotrys (species of which have also been called "black mould").

    Some strains of A. niger have been reported to produce potent mycotoxins called ochratoxins; other sources disagree, claiming this report is based upon misidentification of the fungal species.[citation needed] Recent evidence suggests some true A. niger strains do produce ochratoxin A. It also produces the isoflavone orobol.

    Brief Summary
    provided by EOL authors
    Aspergillus niger is a member of the genus Aspergillus which includes a set of fungi that are generally considered asexual, although perfect forms (forms that reproduce sexually) have been found. Aspergilli are ubiquitous in nature. They are geographically widely distributed, and have been observed in a broad range of habitats because they can colonize a wide variety of substrates. A. niger is commonly found as a saprophyte growing on dead leaves, stored grain, compost piles, and other decaying vegetation. The spores are widespread, and are often associated with organic materials and soil. The primary uses of A. niger are for the production of enzymes and organic acids by fermentation. A. niger is also used to produce organic acids such as citric acid and gluconic acid.

Comprehensive Description

    Aspergillus niger
    provided by wikipedia

    Aspergillus niger is a fungus and one of the most common species of the genus Aspergillus.

    It causes a disease called black mould on certain fruits and vegetables such as grapes, apricots, onions, and peanuts, and is a common contaminant of food. It is ubiquitous in soil and is commonly reported from indoor environments, where its black colonies can be confused with those of Stachybotrys (species of which have also been called "black mould").[1]

    Some strains of A. niger have been reported to produce potent mycotoxins called ochratoxins;[2] other sources disagree, claiming this report is based upon misidentification of the fungal species.[citation needed] Recent evidence suggests some true A. niger strains do produce ochratoxin A.[1][3] It also produces the isoflavone orobol.

    Taxonomy

    Aspergillus niger is included in Aspergillus subgenus Circumdati, section Nigri. The section Nigri includes 15 related black-spored species that may be confused with A. niger, including A. tubingensis, A. foetidus, A. carbonarius, and A. awamori.[4][5] A number of morphologically similar species were recently described by Samson et al.[5]

    Recently the strain of ATCC 16404 Aspergillus niger has been reclassified at Aspergillus brasiliensis (refer to publication by Varga et al.[6]). This has required an update to the U.S. Pharmacopoeia and the European Pharmacopoeia which commonly use this strain throughout the pharmaceutical industry.

    Pathogenicity

    Plant disease

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    A. niger growing on onion

    Aspergillus niger causes black mold of onions and ornamental plants. Infection of onion seedlings by A. niger can become systemic, manifesting only when conditions are conducive. A. niger causes a common postharvest disease of onions, in which the black conidia can be observed between the scales of the bulb. The fungus also causes disease in peanuts and in grapes.

    Human and animal disease

    Aspergillus niger is less likely to cause human disease than some other Aspergillus species. In extremely rare instances, humans may become ill, but this is due to a serious lung disease, aspergillosis, that can occur. Aspergillosis is, in particular, frequent among horticultural workers who inhale peat dust, which can be rich in Aspergillus spores. It has been found in the mummies of ancient Egyptian tombs and can be inhaled when they are disturbed.[7]

    Aspergillus niger is one of the most common causes of otomycosis (fungal ear infections), which can cause pain, temporary hearing loss, and, in severe cases, damage to the ear canal and tympanic membrane.

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    A. niger growing on SDA

    Industrial uses

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    Aspergillus niger is cultured for the industrial production of many substances. Various strains of A. niger are used in the industrial preparation of citric acid (E330) and gluconic acid (E574) and have been assessed as acceptable for daily intake by the World Health Organisation. A. niger fermentation is "generally recognized as safe" (GRAS) by the United States Food and Drug Administration under the Federal Food, Drug, and Cosmetic Act.[8]

    Many useful enzymes are produced using industrial fermentation of A. niger. For example, A. niger glucoamylase is used in the production of high-fructose corn syrup, and pectinases are used in cider and wine clarification. Alpha-galactosidase, an enzyme that breaks down certain complex sugars, is a component of Beano and other products that decrease flatulence. Another use for A. niger within the biotechnology industry is in the production of magnetic isotope-containing variants of biological macromolecules for NMR analysis.

    Aspergillus niger growing from gold-mining solution contained cyano-metal complexes, such as gold, silver, copper, iron, and zinc. The fungus also plays a role in the solubilization of heavy-metal sulfides.[9] Alkali-treated A. niger binds to silver to 10% of dry weight. Silver biosorbtion occurs by stoichiometric exchange with Ca(II) and Mg(II) of the sorbent.

    Other uses

    Aspergillus niger is also cultured for the extraction of the enzyme, glucose oxidase, used in the design of glucose biosensors, due to its high affinity for β-D-glucose.[10][11]

    Genetics

    Genome

    Genomic informationNCBI genome ID 429Ploidy haploidGenome size 34 MbNumber of chromosomes 8

    The A. niger ATCC 1015 genome was sequenced by the Joint Genome Institute in a collaboration with other institutions.[12]

    The genomes of two A. niger strains have been fully sequenced.[13][14]

    See also

    References

    1. ^ a b Samson RA, Houbraken J, Summerbell RC, Flannigan B, Miller JD (2001). "Common and important species of fungi and actinomycetes in indoor environments". Microogranisms in Home and Indoor Work Environments. CRC. pp. 287–292. ISBN 978-0415268004..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"""""'"'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
    2. ^ Abarca M, Bragulat M, Castellá G, Cabañes F (1994). "Ochratoxin A production by strains of Aspergillus niger var. niger". Appl Environ Microbiol. 60 (7): 2650–2. PMC 201698. PMID 8074536.
    3. ^ Schuster E, Dunn-Coleman N, Frisvad JC, Van Dijck PW (2002). "On the safety of Aspergillus niger—a review". Applied Microbiology and Biotechnology. 59 (4–5): 426–35. doi:10.1007/s00253-002-1032-6. PMID 12172605.
    4. ^ Klich MA (2002). Identification of common Aspergillus species. Utrecht, The Netherlands, Centraalbureau voor Schimmelcultures. ISBN 978-90-70351-46-5.
    5. ^ a b Samson, RA, Houbraken JA, Kuijpers AF, Frank JM, Frisvad JC (2004). "New ochratoxin A or sclerotium producing species in Aspergillus section Nigri" (PDF). Studies in Mycology. 50: 45–6.
    6. ^ Varga, J.; Kocsube, S.; Toth, B.; Frisvad, J. C.; Perrone, G.; Susca, A.; Meijer, M.; Samson, R. A. (2007). "Aspergillus brasiliensis sp. nov., a biseriate black Aspergillus species with world-wide distribution". International Journal of Systematic and Evolutionary Microbiology. 57 (8): 1925–32. doi:10.1099/ijs.0.65021-0. PMID 17684283.
    7. ^ Handwerk, Brian (May 6, 2005) Egypt's "King Tut Curse" Caused by Tomb Toxins?. National Geographic.
    8. ^ "Inventory of GRAS Notices: Summary of all GRAS Notices". US FDA/CFSAN. 2008-10-22. Archived from the original on 11 October 2008. Retrieved 2008-10-31.
    9. ^ Singh, Harbhajan (2006). Mycoremediation: Fungal Bioremediation. John Wiley & Sons. p. 509. ISBN 978-0470050583.
    10. ^ Staiano, M.; Bazzicalupo, P.; Rossi, M.; d'Auria, S. (2005). "Glucose biosensors as models for the development of advanced protein-based biosensors". Molecular BioSystems. 1 (5–6): 354–362. doi:10.1039/b513385h. PMID 16881003.
    11. ^ Ghoshdastider U, Wu R, Trzaskowski B, Mlynarczyk K, Miszta P, Gurusaran M, Viswanathan S, Renugopalakrishnan V, Filipek S (2015). "Nano-Encapsulation of Glucose Oxidase Dimer by Graphene". RSC Advances. 5 (18): 13570–78. doi:10.1039/C4RA16852F.
    12. ^ "Home – Aspergillus niger ATCC 1015 v4.0".
    13. ^ Pel H, de Winde J, Archer D, et al. (2007). "Genome sequencing and analysis of the versatile cell factory Aspergillus niger CBS 513.88". Nat Biotechnol. 25 (2): 221–31. doi:10.1038/nbt1282. PMID 17259976.
    14. ^ Andersen MR, Salazar MP, Schaap PJ, et al. (2011). "Comparative genomics of citric-acid-producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88". Genome Res. 21 (6): 885–97. doi:10.1101/gr.112169.110. PMC 3106321. PMID 21543515.

Morphology

    Morphology
    provided by EOL authors
    While morphology provides a reasonable means of classification and assignment within the A. niger group, it is not a reliable means for identifying a given isolate from the field. The major distinction currently separating A. niger from the other species of Aspergillus is the production of carbon black or very dark brown spores from biseriate phialides (Raper and Fennell, 1965). Other features include the smooth and generally colorless conidiophores and spores that are ó5 æm, globose, and have conspicuous ridges or spines not arranged in rows. A. niger isolates grow slowly on Czapek agar (Raper and Fennell, 1965). These physical characters such as spore color and rate of growth on a defined media are subject to change, especially under extended pure culture or selection and mutation. Though A. niger is relatively stable to spontaneous mutation compared to other aspergilli, variation in morphology may still be a problem with some strains (Raper and Fennell, 1965). Thus this species may be misidentified with other Aspergillus spp.

Risks

    Risks
    provided by EOL authors
    Aspergillus niger is worldwide in distribution and has been isolated from numerous habitats. Humans are continually exposed to A. niger spores and vegetative forms on foodstuffs and in the air. The vast majority of strains of A. niger, especially those used in industrial fermentation, have a history of safe use. While there are sporadic reports to the contrary, most isolates have not been documented to be serious pathogens of humans, animals or plants. Specific strains may produce certain mycotoxins or may elicit allergic responses among workers. Those limited instances of adverse effects seem to be associated with a limited number of strains. With proper characterization of industrial strains, use of those with potential for such effects can be avoided.