Aspergillus unguis | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Eurotiomycetes |
Order: | Eurotiales |
Family: | Aspergillaceae |
Genus: | Aspergillus |
Species: | A. unguis |
Binomial name | |
Aspergillus unguis Weill & L.Gaudin (1935) | |
Synonyms [1] [2] | |
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Aspergillus unguis is a species of fungus in the genus Aspergillus , and the asexual state (anamorph) of Emericella unguis. [3] [4] Aspergillus unguis is a filamentous soil-borne fungus [5] found on decomposing plant matter and other moist substrates including with building materials and household dust. [6] Aspergillus unguis occurs mainly in tropical and subtropical soils but has also been isolated from various marine and aquatic habitats. [7] The species was first isolated in 1935 by Weill and L. Gaudin. [4] Historically, A. unguis was assigned to the A. nidulans group, a common group of soil-borne fungi due to the resemblance of its ascospores and cleistothecia to those of Emericella nidulans. [8] Aspergillus unguis is distinctive, however, in possessing spicular hyphae. [8] A number of synonyms have been collapsed into this species, including Sterigmatocystis unguis, Aspergillus laokiashanensis and Aspergillus mellinus. [1]
Colonies typically reach up to 2 cm (0.8 in) in diameter at 10 days incubation, growing optimally at 30 °C (86 °F). [7] A number of growth media are suitable for the cultivation of this species, including Sabouraud maltose agar, Czapek's agar, and Raulin's agar. [7] The colonies of A. unguis are first white in colour, becoming greenish or chrome green in the centre, [7] and ultimately a dull brown colour similar to chocolate. [8] The dark colour is due to the presence of melanin or melanin like-pigments within the cell wall. [9] This dark brown colouration is unique to the species and has caused some researchers to include it in the dematiaceous fungi, a group of unrelated, darkly coloured moulds that includes some serious opportunistic pathogens of humans. [9] Despite its outward similarity to the dematiaceous fungi, the latter group conventionally excludes members of the order Eurotiales.
The conidiophoress are smooth-walled, non-septate, reaching 45–65 μm in length. [7] The mature sporulating heads are 250–300 μm in diameter, and columnar. [7] The conidiophores terminate in hemispherical vesicles 9–12 μm wide, which become covered by primary and secondary metulae giving rise to phialides. [8] The conidia are spherical in shape, roughly 3 μm in diameter and develop brownish vein-like structures on the spore walls over time. [7] Conidia are borne in columns at the tips of aspergilloid conidiophores. [8] The spicular hyphae of A. unguis are aseptate and become brown in colour, thick-walled and irregularly roughened and tapering with blunt apex. [8] They reach a length of 1000 μm or greater. [8]
Aspergillus unguis has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
Aspergillus unguis is a soil-dwelling fungus that prefers high water activity (aw).
Disease of the nails and skin caused by A. unguis has been reported. [6] This species was one of two most common fungi encountered in the homes of asthmatic children in Detroit, Michigan, reported from 72% of homes. [10] It has also been reported as a colonist of water-damaged construction materials in Finland, where it was found to produce the mycotoxin, sterigmatocystin, a potent carcinogen and mutagen. [11]
Production of beta-glucosidases is well known in members of the genus Aspergillus; however, only a few species can produce glucose-tolerant isoforms. Beta-glucosidases produced by A. unguis are characteristically highly glucose-tolerant. [5] For this reason, the fungus has been investigated industrially for use in the hydrolysis of cellulose hydrolysis and biomass conversion (cellulose to glucose to fuel ethanol). [5]
Four bioactive, chlorinated depsidones have been isolated from strains of this species obtained from seaweed collected off the coasts of China and Thailand. [12] These compounds exhibited potent inhibitory effects against methicillin-resistant Staphylococcus aureus (MRSA), brine shrimp larvae (test for compound cytotoxicity and pesticide-ability) and the human lung tumor line A-549. [12] No activity was found against E. coli strain AB1157+; however, some depsidones exhibited selective bioactivity on strain AB3027-. [12] Some compounds introduced DNA damage. [12] One depsidone showed significant anti-proliferatory activity on human cancer cells. [12] Folipastatin, another depsidone, is inhibitory to phospholipase A2, an important enzyme in the lipolysis pathway that also is related to the expression of inflammatory mediators such as arachidonic acid. [13] Exposure of hypertensive rats to this compound produced an anti-inflammatory effect with mild edema at the injection site but without an increase in blood pressure edemas on the hypertensive rats. [13]
Guisinol was isolated from a strain of the teleomorph Emericella unguis derived from a mollusc collected from coastal Venezuela. [14] This compound also inhibits the growth of MRSA in vitro. [14] The metabolite unguinol, produced uniquely by A. unguis, is a growth promoter specific to monogastric animals such as chickens. [15] It also been investigated as a potential herbicide due to its ability to selectively inhibit pyruvate, phosphate dikinase (PPDK), a key enzyme in gluconeogenesis and photosynthesis. [16] Other metabolites produced by the fungus include sterigmatocystin, unguisin A, unguisin B and unguisin C. [17] [18] [19] [20]
In 2016, the genome of A. unguis was sequenced as a part of the Aspergillus whole-genome sequencing project - a project dedicated to performing whole-genome sequencing of all members of the genus Aspergillus. [21] The genome assembly size was 26.06 Mbp. [21]
Aspergillus niger is a mold classified within the Nigri section of the Aspergillus genus. The Aspergillus genus consists of common molds found throughout the environment within soil and water, on vegetation, in fecal matter, on decomposing matter, and suspended in the air. Species within this genus often grow quickly and can sporulate within a few days of germination. A combination of characteristics unique to A. niger makes the microbe invaluable to the production of many acids, proteins and bioactive compounds. Characteristics including extensive metabolic diversity, high production yield, secretion capability, and the ability to conduct post-translational modifications are responsible for A. niger's robust production of secondary metabolites. A. niger's capability to withstand extremely acidic conditions makes it especially important to the industrial production of citric acid.
Aspergillus is a genus consisting of several hundred mold species found in various climates worldwide.
Penicillium roqueforti is a common saprotrophic fungus in the genus Penicillium. Widespread in nature, it can be isolated from soil, decaying organic matter, and plants.
Denitrobacterium is a genus of Actinomycetota with a single species, in the family Coriobacteriaceae. Originally isolated from the bovine rumen, Denitrobacterium are non-motile and non-spore forming. The only described species in this genus is Denitrobacterium detoxificans. The specific niche of this bacterium in the bovine rumen is theorized to be the detoxification/metabolism of nitrotoxins and miserotoxin.
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.
A depside is a type of polyphenolic compound composed of two or more monocyclic aromatic units linked by an ester group. Depsides are most often found in lichens, but have also been isolated from higher plants, including species of the Ericaceae, Lamiaceae, Papaveraceae and Myrtaceae.
Ergosterol peroxide (5α,8α-epidioxy-22E-ergosta-6,22-dien-3β-ol) is a steroid derivative. It has been isolated from a variety of fungi, yeast, lichens and sponges, and has been reported to exhibit immunosuppressive, anti-inflammatory, antiviral, trypanocidal and antitumor activities in vitro.
Aspergillus ochraceus is a mold species in the genus Aspergillus known to produce the toxin ochratoxin A, one of the most abundant food-contaminating mycotoxins, and citrinin. It also produces the dihydroisocoumarin mellein. It is a filamentous fungus in nature and has characteristic biseriate conidiophores. Traditionally a soil fungus, has now began to adapt to varied ecological niches, like agricultural commodities, farmed animal and marine species. In humans and animals the consumption of this fungus produces chronic neurotoxic, immunosuppressive, genotoxic, carcinogenic and teratogenic effects. Its airborne spores are one of the potential causes of asthma in children and lung diseases in humans. The pig and chicken populations in the farms are the most affected by this fungus and its mycotoxins. Certain fungicides like mancozeb, copper oxychloride, and sulfur have inhibitory effects on the growth of this fungus and its mycotoxin producing capacities.
Emericella is a former genus of fungi.
Evariquinone is a chemical compound of the anthraquinone class which has been isolated from a sponge-derived strain of the fungus Emericella variecolor and from Aspergillus versicolor.
Aspergillus versicolor is a slow-growing species of filamentous fungus commonly found in damp indoor environments and on food products. It has a characteristic musty odor associated with moldy homes and is a major producer of the hepatotoxic and carcinogenic mycotoxin sterigmatocystin. Like other Aspergillus species, A. versicolor is an eye, nose, and throat irritant.
Aspergillus glaucus is a filamentous fungus which is known to have a wide environmental distribution due to its physiological hardiness under extreme conditions. Like many other fungi belonging to the genus Aspergillus, it can be mildly pathogenic but has a number of useful potential applications in medicine and the production of foodstuffs.
Aspergillus clavatus is a species of fungus in the genus Aspergillus with conidia dimensions 3–4.5 x 2.5–4.5 μm. It is found in soil and animal manure. The fungus was first described scientifically in 1834 by the French mycologist John Baptiste Henri Joseph Desmazières.
Aspergillus tubingensis is a darkly pigmented species of fungus in the genus Aspergillus section Nigri. It is often confused with Aspergillus niger due to their similar morphology and habitat. A. tubingensis is often involved in food spoilage of fruits and wheat, and industrial fermentation. This species is a rare agent of opportunistic infection.
Aspergillus desertorum is a species of fungus in the genus Aspergillus which has been isolated from desert soil. It is from the Nidulantes section. Aspergillus desertorum produces desertorin A, desertorin B, desertorin C, paxiline and emindol DA.
Aspergillus parasiticus is a fungus belonging to the genus Aspergillus. This species is an unspecialized saprophytic mold, mostly found outdoors in areas of rich soil with decaying plant material as well as in dry grain storage facilities. Often confused with the closely related species, A. flavus, A. parasiticus has defined morphological and molecular differences. Aspergillus parasiticus is one of three fungi able to produce the mycotoxin, aflatoxin, one of the most carcinogenic naturally occurring substances. Environmental stress can upregulate aflatoxin production by the fungus, which can occur when the fungus is growing on plants that become damaged due to exposure to poor weather conditions, during drought, by insects, or by birds. In humans, exposure to A. parasiticus toxins can cause delayed development in children and produce serious liver diseases and/or hepatic carcinoma in adults. The fungus can also cause the infection known as aspergillosis in humans and other animals. A. parasiticus is of agricultural importance due to its ability to cause disease in corn, peanut, and cottonseed.
Aspergillus campestris is a species of fungus in the genus Aspergillus. The species was first described in 1982. It is from the Candidi section. The fungi in the Candidi section are known for their white spores. It has been shown to produce a high number of secondary metabolites.
Penicillium spinulosum is a non-branched, fast-growing fungus with a swelling at the terminal of the stipe (vesiculate) in the genus Penicillium. P. spinulosum is able to grow and reproduce in environment with low temperature and low water availability, and is known to be acidotolerant. P. spinulosum is ubiquitously distributed, and can often be isolated from soil. Each individual strain of P. spinulosum differs from others in their colony morphology, including colony texture, amount of sporulation and roughness of conidia and conidiophores.
Aspergillus wentii is an asexual, filamentous, endosymbiotic fungus belonging to the mold genus, Aspergillus. It is a common soil fungus with a cosmopolitan distribution, although it is primarily found in subtropical regions. Found on a variety of organic materials, A. wentii is known to colonize corn, cereals, moist grains, peanuts and other ground nut crops. It is also used in the manufacture of biodiesel from lipids and is known for its ability to produce enzymes used in the food industry.
Guisinol is an antibacterial depside with the molecular formula C23H25ClO5 that has been isolated from the fungus Aspergillus unguis.
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