Mucor circinelloides | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Mucoromycota |
Order: | Mucorales |
Family: | Mucoraceae |
Genus: | Mucor |
Species: | M. circinelloides |
Binomial name | |
Mucor circinelloides Tieghem (1875) | |
Synonyms | |
Mucor circinelloides is a dimorphic fungus [1] belonging to the Order Mucorales (Phylum Mucoromycota). It has a worldwide distribution, found mostly in soil, dung and root vegetables. This species is described as not known to be able to produce mycotoxins, [2] however it has been frequently reported to infect animals such as cattle and swine, as well as fowl, platypus and occasionally humans. [3] [4] Ketoacidotic patients are particularly at risk for infection by M. circinelloides. [3]
Mucor circinelloides is one of the common species in the genus Mucor. [5] Mucor circinelloides is a variable species that include several variants such as; M. circinelloides f. circinelloides; M. circinelloides f. lusitanicus; M. circinelloides f. griseocyanus and M. circinelloides f. janssenii. [6]
Mucor circinelloides reproduce asexually. The sporangiophores are found as two types: elongate and sympodially branched. [6] The elongate sporangiophores have larger sporangia, which are white at first and progressively turn greenish brown in colour. [6] They assume a globose shape and are 40-80 μm in size; characterized as "bobbing heads". [6] Sporangiophores are mostly sympodially branched [5] with small sporangia (25 μm); [6] branches are and sometimes circinate. [7] The diameter of the sporangia range from 20 to 80 μm. [7] Sporangia have slightly encrusted walls. [5] In larger sporangia, the membranes are deliquescent, whereas they are persistent in the smaller ones and rupture at maturity. [7] [5] Smaller sporangia also have smooth persistent walls. [6] Sporangiophores are ellipsoid (6-7 μm in diameter) or subglobose (4-6 μm in diameter). [7] Numerous chlamydospores are also produced. [5]
Colonies are fast growing and go up to 2 cm in height. [6] On Czapek Yeast Autolysate (CYA) plates, the colony growth is low and sparse, most often spreading across the entire Petri dish. [2] These colonies of 60 mm diameter or more appear to be pale grey or yellow in colour, with the reverse being uncoloured. [2] Colonies also fill up the entire Petri dish of malt extract agar, producing colony colours similar to those observed on CYA. [2] Mucor circinelloides can assume a yeast-like growth form. [6] It has been isolated in this yeast form from human urine and normal stool specimen. [6] It has also been recovered as a yeast from frogs. [6]
Mucor circinelloides has good growth and sporulation between 5-10 °C [4] [5] and very poor growth at 37 °C which is also the maximum growth temperature. [5] [3] The minimal water activity(aw) for growth is 0.9. [4] M. circinelloides assimilates ethanol and nitrate. [3] The length and number of tall sporangiophores decrease with lower temperatures. [4] Spores are broadly ellipsoid (4.4-6.8 x 3.7-4.7 μm [5] Growth, sporulation, and presence of tall and short sporangiophores can be influenced by temperature; however sporangiophore shape, size and uniformity are not influenced by temperatures. [4]
At least 20 species belonging to the genus Mucor are found to be extracted from food. [4] M. circinelloides is one of the five most significant fungus out of these 20 along with M. hiemalis, M. piriformis, M. plumbeus and M. racemosus. [4] It has been reported to spoil cheese and yams as well as diseases of mango. [2] This fungus has also been isolated from various foods such as meat, hazelnuts, walnuts, maize, mung beans, soybeans and barley. [2]
Fungi in the order Mucorales class have not been investigated in detail for their ability to produce mycotoxins; [8] Cytotoxicity and mycotoxin-production was analysed and tested for using the cytotoxicity test (MTT assay) and LC/MS/MS-based multimycotoxin method respectively for three fungal species, including M. circinelloides. [8] Mucor circinelloides was found to be able to produce 3-nitropropionic acid as well as have low cytotoxicity. [8] Conventionally, M. circinelloides is considered not to produce mycotoxins. [2]
Mucor circinelloides is considered an emerging pathogen, although it has only been associated rarely with very human disease and have been limited to cutaneous infection. [9] This species is occasionally isolated from humans, birds, cattle, and swine. [6]
Mucor circinelloides is potentially a rich source of antioxidants and other secondary metabolites which could be used in the development of nutraceuticals and natural antioxidants. [10]
Zygomycota, or zygote fungi, is a former division or phylum of the kingdom Fungi. The members are now part of two phyla: the Mucoromycota and Zoopagomycota. Approximately 1060 species are known. They are mostly terrestrial in habitat, living in soil or on decaying plant or animal material. Some are parasites of plants, insects, and small animals, while others form symbiotic relationships with plants. Zygomycete hyphae may be coenocytic, forming septa only where gametes are formed or to wall off dead hyphae. Zygomycota is no longer recognised as it was not believed to be truly monophyletic.
The Mucorales is the largest and best-studied order of zygomycete fungi. Members of this order are sometimes called pin molds. The term mucormycosis is now preferred for infections caused by molds belonging to the order Mucorales.
Mucor mucedo, commonly known as the common pinmould, is a fungal plant pathogen and member of the phylum Mucoromycota and the genus Mucor. Commonly found on soil, dung, water, plants and moist foods, Mucor mucedo is a saprotrophic fungus found world-wide with 85 known strains. It is often mistaken for Rhizopus rots on fruits due to similar mould growth shape and colour. Contrastingly, however, Mucor mucedo is found to grow on a wide range of stored grains and plants, including cucumber and tomato. Discovered in Italy in 1729 by P.A. Micheli and later noted by Carl Linnaeus in 1753 in the Species Plantarum, Mucor mucedo was originally classified as Mucor vulgaris by Micheli but later classified synonymous under name Mucor mucedo. The species was redescribed as Ascophora mucedo by H.J. Tode in 1790 but this type resided in a stoloniferous habitat and was later made the type of new genus Rhizopus.
Mucor racemosus is a rapidly growing, weedy mould belonging to the division Mucoromycota. It is one of the earliest fungi to be grown in pure culture and was first isolated in 1886. It has a worldwide distribution and colonizes many habitats such as vegetational products, soil and houses. The fungus is mostly known for its ability to exhibit both filamentous and yeast-like morphologies, often referred to as dimorphism. Stark differences are seen in both forms and conditions of the environment heavily affect the phases of the M. racemosus. Like many fungi, it also reproduces both sexually and asexually. The dimorphic capacity of this species has been proposed as an important factor in its pathogenicity and has enhanced the industrial importance. This species is considered an opportunistic pathogen, generally limited to immunocompromised individuals. It also been associated with allergy and inflammations of facial sinuses. Its association with allergy has made it a common fungus used in allergen medical testing. Industrial use of the fungus is in the production of enzymes and the manufacture of certain dairy foods.
Mucor amphibiorum is a fungus found in Australia that causes infections in amphibians and platypuses. Because M. amphibiorum belongs to the genus Mucor, the infection is classified as a form of mucormycosis. The fungus was first reported from a German zoo in 1972 where it caused disease in a species of green tree frog that was imported from Australia and infected frogs, toads, and salamanders in neighboring exhibits. It is most commonly found in frogs and toads in Queensland, New South Wales, and Northern Territory, and in platypuses in Tasmania.
Spinellus fusiger, commonly known as bonnet mold, is a species of fungus in the phylum Mucoromycota. It is a pin mold that is characterized by erect sporangiophores that are simple in structure, brown or yellowish-brown in color, and with branched aerial filaments that bear the zygospores. It grows as a parasitic mold on mushrooms, including several species from the genera Mycena, including M. haematopus, M. pura, M. epipterygia, M. leptocephala, and various Collybia species, such as C. alkalivirens, C. luteifolia, C. dryophila, and C. butyracea. It has also been found growing on agaric species in Amanita, Gymnopus, and Hygrophorus.
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.
Chaetomium globosum is a well-known mesophilic member of the mold family Chaetomiaceae. It is a saprophytic fungus that primarily resides on plants, soil, straw, and dung. Endophytic C. globosum assists in cellulose decomposition of plant cells. They are found in habitats ranging from forest plants to mountain soils across various biomes. C. globosum colonies can also be found indoors and on wooden products.
Mucor plumbeus is a fungus in the family Mucoraceae that is very common, abundant and distributed worldwide. Mucor plumbeus is not known to be a plant or animal pathogen; however it is able to elicit an immune response in humans by activating the complement system. This species is commonly found in various types of soils over a range of pH, although alkaline soils seem more conducive to its growth. It is also known from the roots of wheat, oat and barley. In addition, M. plumbeus is a common fungal contaminant of indoor built environments. This species shares many similarities with M. racemosus, another fungus that belongs to the family Mucoraceae which is known to cause mucormycosis. Mucor plumbeus is a common spoilage agent of cheese, apples, apple cider and yogurt.
Cunninghamella bertholletiae is a species of zygomycetous fungi in the order Mucorales. It is found globally, with increased prevalence in Mediterranean and subtropical climates. It typically grows as a saprotroph and is found in a wide variety of substrates, including soil, fruits, vegetables, nuts, crops, and human and animal waste. Although infections are still rare, C. betholletiae is emerging as an opportunistic human pathogen, predominantly in immunocompromised people, leukemia patients, and people with uncontrolled diabetes. Cunninghamella bertholletiae infections are often highly invasive, and can be more difficult to treat with antifungal drugs than infections with other species of the Mucorales, making prompt and accurate recognition and diagnosis of mycoses caused by this fungus an important medical concern.
Rhizopus oryzae is a filamentous heterothallic microfungus that occurs as a saprotroph in soil, dung, and rotting vegetation. This species is very similar to Rhizopus stolonifer, but it can be distinguished by its smaller sporangia and air-dispersed sporangiospores. It differs from R. oligosporus and R. microsporus by its larger columellae and sporangiospores. The many strains of R. oryzae produce a wide range of enzymes such as carbohydrate digesting enzymes and polymers along with a number of organic acids, ethanol and esters giving it useful properties within the food industries, bio-diesel production, and pharmaceutical industries. It is also an opportunistic pathogen of humans causing mucormycosis.
Penicillium verrucosum is a psychrophilic fungus which was discovered in Belgium and introduced by Dierckx in 1901. Six varieties of this species have been recognized based primarily on differences in colony colour: P. verrucosum var. album, P. verrucosum var. corymbiferum, P. verrucosum var. cyclopium, P. verrucosum var. ochraceum, P. verrucosum var. melanochlorum and P. verrucosum var. verrucosum. This fungus has important implications in food, specifically for grains and other cereal crops on which it grows. Its growth is carefully regulated in order to reduce food spoilage by this fungi and its toxic products. The genome of P. verrucosum has been sequenced and the gene clusters for the biosyntheses of its mycotoxins have been identified.
Rhizopus stolonifer is commonly known as black bread mold. It is a member of Zygomycota and considered the most important species in the genus Rhizopus. It is one of the most common fungi in the world and has a global distribution although it is most commonly found in tropical and subtropical regions. It is a common agent of decomposition of stored foods. Like other members of the genus Rhizopus, R. stolonifer grows rapidly, mostly in indoor environments.
Botryotrichum murorum is a common soil and indoor fungus resembling members of the genus Chaetomium. The fungus has no known asexual state, and unlike many related fungi, is intolerant of high heat exhibiting limited growth when incubated at temperatures over 35 °C. In rare cases, the fungus is an opportunistic pathogen of marine animals and humans causing cutaneous and subcutaneous infection.
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.
Cladosporium herbarum is a common fungus found worldwide in organic and inorganic matter. It is efficiently distributed in the air, where it exists as the most frequently occurring fungal species. It can grow over a wide range of temperatures including very cold environments, giving it the ability to grow on refrigerated meat and form "black spots". Its high prevalence in the air and production of allergens makes C. herbarum an important exacerbant of asthma and hay fever.
Mortierella polycephala is a saprotrophic fungus with a wide geographical distribution occurring in many different habitats from soil and plants to salt marshes and slate slopes. It is the type species of the genus Mortierella, and was first described in 1863 by Henri Coemans. A characteristic feature of the fungus is the presence of stylospores, which are aerial, spiny resting spores (chlamydospores).
Syzygites is a monotypic genus in Zygomycota. The sole described species is Syzygites megalocarpus, which was the first fungus for which sex was reported and the main homothallic representative in the research that allowed for the classification of fungi as homothallic or heterothallic. It is also the fungus from which the term "zygospore" was coined.
Myriodontium keratinophilum is a fungus widespread in nature, most abundantly found in keratin-rich environments such as feathers, nails and hair. Despite its ability to colonize keratinous surfaces of human body, the species has been known to be non-pathogenic in man and is phylogentically distant to other human pathogenic species, such as anthropophilic dermatophytes. However, its occasional isolation from clinical specimens along with its keratinolytic properties suggest the possibility it may contribute to disease.
Mucor fragilis is an endophytic fungus that causes the mold that can be found on grapes, pole beans, loquat, and on the roots of medicinal plants like Radix pseudostellariae. It belongs to the order Mucorales and phylum Mucoromycota. The observed symptoms showed the presence of fluffy and soft fungal mycelium with white to dark brown discoloration that deteriorated the beans and grapes quality.