Cunninghamella echinulata

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Cunninghamella echinulata
Cunninghamella echinulata UAMH11661.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Mucoromycota
Order: Mucorales
Family: Cunninghamellaceae
Genus: Cunninghamella
Species:
C. echinulata
Binomial name
Cunninghamella echinulata
(Thaxt.) Thaxt. ex Blakeslee (1905)
Subspecies

Cunninghamella echinulata var. antarctica
Cunninghamella echinulata var. echinulata
Cunninghamella echinulata var. nodosa
Cunninghamella echinulata var. verticillata

Contents

Synonyms

Cunninghamella echinulata is a fungal species in the genus Cunninghamella. [1] It is an asexually reproducing fungus and a mesophile, preferring intermediate temperature ranges. [1] [2] C. echinulata is a common air contaminant, [3] and is currently of interest to the biotechnology industry due to its ability to synthesize γ-linolenic acid [4] as well as its capacity to bioconcentrate metals. [5] This species is a soil saprotroph that forms rhizoids, [3] preferring soils enriched in nitrogen, phosphorus and potassium. [2] It has been reported occasionally an agent of mucormycosis following the inhalation of fungal spores. [6] Czapek's agar is a suitable growth medium for the propagation of C. echinulata. [7]

Taxonomy, growth and morphology

Cunninghamella echinulata is a member of the family, Cunninghamellaceae (phylum Mucoromycota). [1] [8] This species is closely related to C. elegans , and both species share highly similar characteristics of growth and morphology. Colonies tend to be rapidly growing on most growth media producing a dense, white or greyish aerial mycelium. [9] Cunninghamella echinulata reproduces asexually and solely via yellow-brown, spiny, single-spored sporangioles that, due to the nature of the sporangiospore being retained within the sporangium, appear to have a two-layered outer wall. [1] [10] [11] This fungus grows by means of filaments that lack septa. [6] [12] This is a common feature of members if the Mucoromycota where the hyphal compartments are either fully divided by septa or are completely continuous (coenocytic) and multinucleate. Zygospores of this fungus are only produced following the fusion of gametangia of compatible mating strains, exemplifying a heterothallic mating system. [13] Sporangiophores of this species are irregularly branched and do not resemble the sporangiospores typical of most other members of the Mucoromycota encountered in similar habitats. [13] [9] The sporangioles produced by this fungus are larger in size (10–20 μm) than those of the closely related species, C. elegans. [13]

Physiology

Cunninghamella echinulata and other species of Cunninghamellaceae can be selectively grown on Czapek's solution agar, [7] a property unique to this family of the Mucorales. However, depending on the nutrients the agar is supplemented with, different media can alter the oxidative metabolism profile of this fungus. [14] This species grows better on acetate than d-glucose. [2] Additionally, if grown in liquid, cultures of this fungus can be externally stimulated to increase oxygen consumption by adding 2% montmorillonite or kaolinite. [2]

While this fungus is a mesophilic (preferring intermediate growth temperatures), it is able to grow between 6 °C (43 °F) and 45 °C (113 °F) although the rate of growth near the extremes of temperature tolerance is minimal. [2] [6] The optimal temperature for the development of zygospores is between 25 °C (77 °F) and 35 °C (95 °F). [2] This species exhibits different growth characteristic depending on environmental influences. At a pH of 5.5, the fungus grows in small dense pellets; [14] but a more typical, radiating growth pattern is achieved at a pH of 8.0, [14] The presence of indole-3-acetic acid in the growth medium stimulates linear growth. [2]

When grown on medium containing hydrolysed tomato residue, this fungus utilizes glucose to synthesize triacylglycerols (TAG) rich in GLA. [4] This fungus has been investigated for use in the production of single cell oils (SCO) and storage lipids (like GLA). [15] C. echinulata is also able to selectively take up and sequester metal contaminants from polluted waters, suggesting a potential use in bioremediation of polluted water. [5] However, its role as an agent of opportunistic disease may limit its use in environmental remediation. Cunninghamella echinulata is able to grow on orange rind and assimilate carbohydrates into necessary biomolecules, [15] where the fermented peel does not exhibit appreciable discolouration or odour. [15] Growth of this fungus on organic nitrogen leads yields lipids rich in γ-linolenic acid (GLA). [4] The presence of an active monooxygenase system allows this species to perform oxidative demethylation and hydroxylation. [2] The fungus possesses a p450 cytochrome system similar to that in humans, making it a potentially useful model for the study liver-mediated drug metabolism. [14]

This species is also able to stereoselectively biotransform rac-mexiletine into hydroxymethyl mexiletine (HMM) and p-hydroxymexiletine (PHM), two metabolites also produced in humans. [14] Cunninghamella echinulata grown in yeast extract broth, trypticase soy medium or peptone broth at a pH of 8 yielded 0 μg/ml of breakdown products from the metabolism of rac-mexiletine. [14] The production of maximal HMM is achieved in yeast extract broth at a pH of 7.0. [14] Metabolic activity diminishes with increasing pH up to a maximum pH of 8.0. [14] At increased pH, C. echinulata shows preferential production of S-HMM over R-HMM, the two stereoisomers, specifically enantiomers, of HMM. [14] In order to achieve the highest quantity of GLA, Cunninghamella echinulata grows preferentially on nitrogen-depleted media with a C/N (carbon:nitrogen) molar ratio of 169. [15]

The species has been reported to exhibit antibacterial effects against Staphylococcus aureus and Salmonella typhus, [2] common agents of skin infections and food poisoning respectively. It is also known to inhibit root growth in various grass species in vitro. [2] The fungus is not known to produce mycotoxins. [13]

Habitat and ecology

Cunninghamella echinulata is a saprotrophic resident of the soils in warmer regions of the world, particularly those enriched with NPK fertilizers (Nitrogen, Phosphorus and Potassium). [1] [2] It has been reported from both cultivated and uncultivated soils, [9] [16] including soils from greenhouses and forests [7] in the mediterranean and subtropical zones but is thought to be comparatively rare in temperate zones. [9] [13] Soil depth and pH are not considered to be strongly influential on the growth properties of this fungus in vivo. [2] This species is able to cause rot in foods such as Kola nuts [13] and is a common air contaminant. [3] It can be parasitized by other fungi including species of Piptocephalis, [12] and Trichoderma viride. [2] Additionally, its growth is inhibited in vitro by the fungus, Memnoniella echinata. [2]

Human disease

Disease caused by this fungus and other species of Mucorales is referred to as mucormycosis characterized by a rapidly progressive and destructively invasive disease with relatively low survival. [6] Literature reporting this agent in healthy people is lacking. As a consequence, this species is thought to be exclusively an opportunistic pathogen, affecting individuals with pre-existing health conditions. People with underlying health conditions such as HIV infection and diabetes are at heightened risk for mucormycosis. [6] Infections by C. echinulata are thought to arise from inhalation of fungal spores and are not communicable. [6] Relatively few case reports implicating C. echinulata are available. Of those that are, one prototypical case from 2005 reported a fatal rhinocerebral infection in a 15-year-old boy suffering from acute leukaemia. [6] Biopsy of the infected nasal tissue showed signs of necrosis and vascular invasion. [6]

Cunninghamella echinulata, like other members of the genus, exhibit strong resistance to the antifungal polyene, amphotericin B with a MIC (Minimum Inhibitory Concentration) ranging from 4-16μg/mL that varies according to strain. [6] Strains of C. echinulata also display greater tolerance to itraconazole and posaconazole than other members of the Mucorales. [6] The antifungal agent terbinafine, typically restricted to the treatment of nail and skin infections, shows a relatively low MIC ranging from 0.06 to 0.125 μg/mL. [6]

Biotechnology

It is commonly cultivated for its ability to produce GLA, [4] preferentially synthesizing R-PHM and S-HMM. [14] The fungus is able to synthesize γ-linolenic acid. [4] It also possesses the ability to bioabsorb metals, with the highest levels of bioabsorption reported 5 to 15 minutes after contact with the metals. [5] Adding NaOH to this fungus before it absorbs metals enhances the uptake of Pb, Cu and Zn. [5] These uptake rates also seem to be influenced by pH where at a pH of 7.1, Zn was the most highly absorbed metal, [5] at a pH of 4, Pb was the most highly absorbed metal [5] and at a pH of 5, Cu was the most highly absorbed metal. [5] Cunninghamella echinulata has been used to transform cortexolone to hydrocortisone. [17] Hydroxylation of biphenyl oxide has been studied in C. echinulata. [18]

Related Research Articles

<span class="mw-page-title-main">Zygomycota</span> Division or phylum of the kingdom Fungi

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.

<span class="mw-page-title-main">Zygomycosis</span> Medical condition

Zygomycosis is the broadest term to refer to infections caused by bread mold fungi of the zygomycota phylum. However, because zygomycota has been identified as polyphyletic, and is not included in modern fungal classification systems, the diseases that zygomycosis can refer to are better called by their specific names: mucormycosis, phycomycosis and basidiobolomycosis. These rare yet serious and potentially life-threatening fungal infections usually affect the face or oropharyngeal cavity. Zygomycosis type infections are most often caused by common fungi found in soil and decaying vegetation. While most individuals are exposed to the fungi on a regular basis, those with immune disorders (immunocompromised) are more prone to fungal infection. These types of infections are also common after natural disasters, such as tornadoes or earthquakes, where people have open wounds that have become filled with soil or vegetative matter.

<span class="mw-page-title-main">Mucorales</span> Order of fungi

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.

<i>Mortierella</i> Genus of fungi

Mortierella species are soil fungi belonging to the order Mortierellales within the subphylum Mortierellomycotina. The widespread genus contains about 85 species.

<i>Apophysomyces</i> Genus of fungi

Apophysomyces is a genus of filamentous fungi that are commonly found in soil and decaying vegetation. Species normally grow in tropical to subtropical regions.

<i>Aspergillus terreus</i> Species of fungus

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.

<i>Mucor mucedo</i> Species of fungus

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.

<i>Mucor racemosus</i> Species of fungus

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.

Pathogenic fungi are fungi that cause disease in humans or other organisms. Although fungi are eukaryotic, many pathogenic fungi are microorganisms. Approximately 300 fungi are known to be pathogenic to humans; their study is called "medical mycology". Fungal infections are estimated to kill more people than either tuberculosis or malaria—about two million people per year.

<span class="mw-page-title-main">Mucormycosis</span> Fungal infection

Mucormycosis, also known as black fungus, is a serious fungal infection that comes under fulminant fungal sinusitis, usually in people who are immunocompromised. It is curable only when diagnosed early. Symptoms depend on where in the body the infection occurs. It most commonly infects the nose, sinuses, eyes and brain resulting in a runny nose, one-sided facial swelling and pain, headache, fever, blurred vision, bulging or displacement of the eye (proptosis), and tissue death. Other forms of disease may infect the lungs, stomach and intestines, and skin.

<i>Conidiobolus coronatus</i> Species of fungus

Conidiobolus coronatus is a saprotrophic fungus, first described by Costantin in 1897 as Boudierella coronata. Though this fungus has also been known by the name Entomophthora coronata, the correct name is Conidiobolus coronatus. C. coronatus is able to infect humans and animals, and the first human infection with C. coronatus was reported in Jamaica in 1965.

Cunninghamella elegans is a species of fungus in the genus Cunninghamella found in soil.

<i>Apophysomyces variabilis</i> Species of fungus

Apophysomyces variabilis is an emerging fungal pathogen that can cause serious and sometimes fatal infection in humans. This fungus is a soil-dwelling saprobe with tropical to subtropical distribution. It is a zygomycete that causes mucormycosis, an infection in humans brought about by fungi in the order Mucorales. Infectious cases have been reported globally in locations including the Americas, Southeast Asia, India, and Australia. Apophysomyces variabilis infections are not transmissible from person to person.

<i>Lichtheimia corymbifera</i> Species of fungus

Lichtheimia corymbifera is a thermophilic fungus in the phylum Zygomycota. It normally lives as a saprotrophic mold, but can also be an opportunistic pathogen known to cause pulmonary, CNS, rhinocerebral, or cutaneous infections in animals and humans with impaired immunity.

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.

<i>Rhizopus stolonifer</i> Species of fungus

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.

<i>Mucor circinelloides</i> Species of fungus

Mucor circinelloides is a dimorphic fungus belonging to the Order Mucorales. 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, however it has been frequently reported to infect animals such as cattle and swine, as well as fowl, platypus and occasionally humans. Ketoacidotic patients are particularly at risk for infection by M. circinelloides.

Mycotypha microspora, also known as Microtypha microspora, is a filamentous fungus in the division Zygomycota. It was discovered in a Citrus aurantium peel in 1932 by E. Aline Fenner, who proposed a new genus Mycotypha to accommodate it. Mycotypha africana, which is another species in the genus Mycotypha, is closely related to M. microspora. The fungus has subsequently been isolated from both outdoor and indoor settings around the world, and is typically found in soil and dung. The species rarely causes infections in humans, but has recently been involved in the clinical manifestation of the life-threatening disease mucormycosis.

<span class="mw-page-title-main">Mucoromycota</span> Diverse group of molds

Mucoromycota is a division within the kingdom fungi. It includes a diverse group of various molds, including the common bread molds Mucor and Rhizopus. It is a sister phylum to Dikarya.

Calcarisporiellaceae is a family of fungi within the subkingdom Mucoromycota. It is the only family in the order Calcarisporiellales, class Calcarisporiellomycetes, subphylum Calcarisporiellomycotina and phylum Calcarisporiellomycota. It contains two known genera, Calcarisporiella and Echinochlamydosporium. The two genera each have one species.

References

  1. 1 2 3 4 5 Webster, John (1980). Introduction to Fungi . Cambridge: Cambridge university press. pp.  230. ISBN   0-521-22888-3.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Domsch, Gams, Heidi-Anderson, K.H, W, Traute (1980). Compendium of Soil Fungi (Vol I). Academic Press. p. 238.{{cite book}}: CS1 maint: multiple names: authors list (link)
  3. 1 2 3 Skinner, Charles (1947). Molds, Yeasts and Actinomycetes. New York: John Wiley & Sons. p. 92.
  4. 1 2 3 4 5 De-Wei, Li (2016). Biology of Microfungi. Springer. p. 555. ISBN   9783319291376.
  5. 1 2 3 4 5 6 7 El-Morsy, El-Sayed M. (2016-12-01). "Cunninghamella echinulata a new biosorbent of metal ions from polluted water in Egypt". Mycologia. 96 (6): 1183–1189. doi:10.2307/3762133. ISSN   0027-5514. JSTOR   3762133. PMID   21148940.
  6. 1 2 3 4 5 6 7 8 9 10 11 LeBlanc, Robert E.; Meriden, Zina; Sutton, Deanna A.; Thompson, Elizabeth H.; Neofytos, Dionissios; Zhang, Sean X. (2013-08-01). "Cunninghamella echinulata causing fatally invasive fungal sinusitis". Diagnostic Microbiology and Infectious Disease. 76 (4): 506–509. doi:10.1016/j.diagmicrobio.2013.03.009. ISSN   1879-0070. PMID   23602784.
  7. 1 2 3 Mycology Guidebook . Seattle and London: University of Washington press. 1974. pp.  94, 96, 97. ISBN   0-295-95313-6.
  8. ↑ Hawker, Lilian (1966). Fungi. London: Hutchinson University library. p. 76.
  9. 1 2 3 4 L. O.Donnell, Kerry (1979). Zygomycetes in Culture. Dept. of Botany, University of Georgia. p. 236.
  10. ↑ Khan (1975). "Wall Structure and Germination of Spores in Cunninghamella echinulata". Journal of General Microbiology. 90: 115–124. doi: 10.1099/00221287-90-1-115 .
  11. ↑ Watanabe, Tsuneo (2010). Pictorial Atlas of Soil and Seed Fungi. New York: CRC press. p. 69.
  12. 1 2 Gwynne-Vaughan, Barnes, H.C.I, B. (1927). Structure and Development of the Fungi. New York: The Macmillan company. pp. 115, 116.{{cite book}}: CS1 maint: multiple names: authors list (link)
  13. 1 2 3 4 5 6 Pitt, Hocking, John, Ailsa (1999). Fungi and Food Spoilage (2nd ED). Springer. pp. 178–180. ISBN   978-0-387-92206-5.{{cite book}}: CS1 maint: multiple names: authors list (link)
  14. 1 2 3 4 5 6 7 8 9 10 Freitag, D. G; Foster, R. T; Coutts, R. T; Pickard, M. A; Pasutto, F. M (1997). "Stereoselective metabolism of rac-mexiletine by the fungus Cunninghamella echinulata yields the major human metabolites hydroxymethylmexiletine and p-hydroxymexiletine". Drug Metab Dispos. 25 (6): 685–692. PMID   9193869.
  15. 1 2 3 4 Gema, H.; Kavadia, A.; Dimou, D.; Tsagou, V.; Komaitis, M.; Aggelis, G. (2002). "Production of γ-linolenic acid by Cunninghamella echinulata cultivated on glucose and orange peel". Applied Microbiology and Biotechnology. 58 (3): 303–307. doi:10.1007/s00253-001-0910-7. ISSN   0175-7598. PMID   11935180. S2CID   2346913.
  16. ↑ Dennis, R.W.G (1986). Fungi of the Hebrides. Kew: Royal Botanic Gardens. p. 231. ISBN   0-947643-02-8.
  17. ↑ Manosroi, J.; Chisti, Y.; Manosroi, A. (2006). "Biotransformation of cortexolone to hydrocortisone by molds using a rapid color development assay". Prikladnaia Biokhimiia I Mikrobiologiia. 42 (5): 547–551. PMID   17066954.
  18. ↑ Seigle-Murandi, F. M.; Krivobok, S. M. A.; Steiman, R. L.; Benoit-Guyod, J. L. A.; Thiault, G. A. (1991). "Biphenyl oxide hydroxylation by Cunninghamella echinulata". Journal of Agricultural and Food Chemistry. 39 (2): 428. doi:10.1021/jf00002a041.
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