Penicillium verrucosum

Last updated

Penicillium verrucosum
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Eurotiomycetes
Order: Eurotiales
Family: Aspergillaceae
Genus: Penicillium
Species:
P. verrucosum
Binomial name
Penicillium verrucosum
Dierckx (1901)
Synonyms

Penicillium verrucosum is a psychrophilic fungus [2] which was discovered in Belgium [1] and introduced by Dierckx in 1901. [3] 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. [3] This fungus has important implications in food, specifically for grains and other cereal crops on which it grows. [4] 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. [2]

Contents

Taxonomy

Penicillium verrucosum was initially incorrectly placed in synonymy with the species Penicillium viridicatum by Raper and Thom. [5] Later, after disagreements arose upon the identification and naming of these fungi, their growth rates, mycotoxin productions and sources were observed. [6] Careful observation concluded that P. verrucosum and P. viridicatum were indeed separate species. Experimental results showed that the mycotoxins ochratoxin A and citrinin are produced by P. verrucosum but not by P. viridicatum. [6]

Habitat and ecology

Penicillium verrucosum is found in temperate and cooler climates. [7] It is found predominantly in northern Europe, including countries such as Scandinavia, Ukraine, Denmark, Sweden, United Kingdom, Yugoslavia, Italy, and Turkey, [7] [8] certain parts of North America, such as Canada, [9] and parts of South America. [10] P. verrucosum grows on grains, seeds and decaying vegetation. [7] It is widely distributed in food (such as cereal [4] ) and animal feed where grains (usually barley, wheat and rye [4] ) are a key ingredient. [9]

Growth and morphology

Penicillium verrucosum is found to be slow-growing: it achieves between 15 mm and 25 mm of growth in diameter on both Czapek Yeast Agar (CYA) and Malt Extract Agar (MEA) after seven days. [11] P. verrucosum has a white mycelium and greyish-green to dull green conidia on the aforementioned media. [11] The reverse is coloured yellow brown to deep brown on CYA and dull brown to olive on MEA. [11] Other varieties of P. verrucosum can have differently coloured conidia, including the colours dark green and blue-green. [12] This fungus has a greater number of conidia growth on CYA than MEA. [11] The conidia are smooth-walled and approximately 2.5 μm to 3.0 μm in diameter. [11] These conidia begin in an ellipsoidal shape when young, and later change to a globose or subglobose shape. [8] P. verrucosum possesses conidiophores which are usually two-stage branched (sometimes three-stage branched), giving it a brush-like appearance. [13] The conidiophores of P. verrucosum are rough-walled with branches and metulae that are pressed closely together. [12] The phialides of the conidiophore are short and flask-shaped with distinct necks. [12]

Penicillium verrucosum has a distinctive odour which is described as earthy and pungent. [12]

Physiology

Of the genus Penicillium, only about half of the identified species are able to grow at the body temperature of mammals. [7] P. verrucosum is not one of these species as there is usually no growth of this fungus at 37 °C. [8] The conidia of P. verrucosum have the ability to germinate at temperatures between 0 °C and 31 °C, [11] but optimal temperatures for germination are between 21 °C and 23 °C. [8] Metabolic products of this fungi include 2-octen-1-ol and 1-octanol and ochratoxin A, brevianamide A, citrinin, penicillic acid, ergosterol, ergosteryl palmitate, meso-erythritol, mannitol, viridicatic acid, viridicatol, viridicatin, xanthomegnin, viomellein, rubrosulphin, viopurpurin, 3-O-methylviridicatin, cyclopenin, cyclopenol. [8]

Ochratoxin A

Penicillium verrucosum produces a very potent mycotoxin called ochratoxin A (OTA). [7] This mycotoxin is immunosuppressive and teratogenic. [11] It has also been classified as genotoxic [10] and a possible human carcinogen. [14] Pigs raised in northern and central Europe develop nephritis after consumption of contaminated feed. [7] The consumption of contaminated barley has been found to be toxic to rats and of contaminated rice has proven to be toxic to mice. [8]

Storage conditions

Penicillium verrucosum is a contaminant of cereal crops (such as barley, maize, oats and wheat) which are used in animal feed. [4] These grains become contaminated with this mycotoxin when they are not carefully prepared after harvest and when storage conditions are unsuitable. [4] When grains are properly stored, OTA levels tend to average around 1 μg/kg in temperate areas. [10]

Spoilage of the grain by OTA occurs as a cause of inappropriate storage temperatures and moisture content. [15] OTA synthesis occurs at moisture content levels between 18% and 22%, and OTA production increases when temperatures are between 10 °C and 21 °C. [15] OTA formation does not occur at moisture content levels below 18% and at temperatures above 28 °C. [15]

Prevention and reduction of contamination

To prevent OTA formation, grains must be dried to moisture levels lower than the 18% limit shortly after harvest. [16] Any spoiled commodities should be kept apart from the uncontaminated harvest, and should not be used in food or feed production. [10] Many countries have regulations regarding recommended and permitted levels of OTA in grains which should be followed. [10]

Complete prevention of OTA contamination is ideal, but many methods exist to reduce existing OTA levels, usually classified into physical, chemical and biological procedures. [17] Physical methods are used remove the contaminated grains through sorting and separation. [17] Chemical procedures aim to eliminate this mycotoxin through processes such as ammoniation, ozonation and nixtamalization. [17] Biological processes use microorganisms to decompose or adsorb OTA in contaminated commodities. [17] Protozoa, bacteria, yeast, filamentous fungi and plant cell cultures are all used in these biological procedures. [17] Microorganisms are beneficial for this purpose as they are environmentally-friendly and do not affect the grain quality. [17]

Disease in humans

During the 1950s, reports of kidney disease with high rates of mortality were occurring in geographically close areas, such as Bulgaria, Yugoslavia and Romania. [14] This occurrence was called the Balkan Endemic Nephropathy [14] that was being caused by the consumption of contaminated pig meat in those areas. [7] When pigs consumed feed contaminated by OTA, it collected in their fatty tissue rather than being excreted due to its solubility in fat. [11] Humans then consumed contaminated pig meat, allowing this mycotoxin to enter the human system. [9]

OTA is mainly found in blood samples in Europe, [7] but its presence in healthy human blood shows that there is still worldwide exposure. [14] An effort has been made in Europe to monitor the OTA levels in foods by creating regulations regarding maximum acceptable levels. [4] Creating guidelines allows for special attention to be paid to local specialties, such as blood puddings and sausages, which are made using pig blood. [4]

Related Research Articles

<span class="mw-page-title-main">Mold</span> Wooly, dust-like fungal structure or substance

A mold or mould is one of the structures that certain fungi can form. The dust-like, colored appearance of molds is due to the formation of spores containing fungal secondary metabolites. The spores are the dispersal units of the fungi. Not all fungi form molds. Some fungi form mushrooms; others grow as single cells and are called microfungi.

<span class="mw-page-title-main">Fusarium ear blight</span> Fungal disease of cereals

Fusarium ear blight (FEB), is a fungal disease of cereals, including wheat, barley, oats, rye and triticale. FEB is caused by a range of Fusarium fungi, which infects the heads of the crop, reducing grain yield. The disease is often associated with contamination by mycotoxins produced by the fungi already when the crop is growing in the field. The disease can cause severe economic losses as mycotoxin-contaminated grain cannot be sold for food or feed.

<i>Penicillium</i> Genus of fungi

Penicillium is a genus of ascomycetous fungi that is part of the mycobiome of many species and is of major importance in the natural environment, in food spoilage, and in food and drug production.

A mycotoxin is a toxic secondary metabolite produced by fungi and is capable of causing disease and death in both humans and other animals. The term 'mycotoxin' is usually reserved for the toxic chemical products produced by fungi that readily colonize crops.

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

Aspergillus flavus is a saprotrophic and pathogenic fungus with a cosmopolitan distribution. It is best known for its colonization of cereal grains, legumes, and tree nuts. Postharvest rot typically develops during harvest, storage, and/or transit. Its specific name flavus derives from the Latin meaning yellow, a reference to the frequently observed colour of the spores. A. flavus infections can occur while hosts are still in the field (preharvest), but often show no symptoms (dormancy) until postharvest storage or transport. In addition to causing preharvest and postharvest infections, many strains produce significant quantities of toxic compounds known as mycotoxins, which, when consumed, are toxic to mammals. A. flavus is also an opportunistic human and animal pathogen, causing aspergillosis in immunocompromised individuals.

<i>Penicillium roqueforti</i> Species of fungus

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.

<span class="mw-page-title-main">Citrinin</span> Chemical compound

Citrinin is a mycotoxin which is often found in food. It is a secondary metabolite produced by fungi that contaminates long-stored food and it causes different toxic effects, like nephrotoxic, hepatotoxic and cytotoxic effects. Citrinin is mainly found in stored grains, but sometimes also in fruits and other plant products.

Mycotoxicology is the branch of mycology that focuses on analyzing and studying the toxins produced by fungi, known as mycotoxins. In the food industry it is important to adopt measures that keep mycotoxin levels as low as practicable, especially those that are heat-stable. These chemical compounds are the result of secondary metabolism initiated in response to specific developmental or environmental signals. This includes biological stress from the environment, such as lower nutrients or competition for those available. Under this secondary path the fungus produces a wide array of compounds in order to gain some level of advantage, such as incrementing the efficiency of metabolic processes to gain more energy from less food, or attacking other microorganisms and being able to use their remains as a food source.

<i>Penicillium expansum</i> Species of fungus

Penicillium expansum is a psychrophilic blue mold that is common throughout the world in soil. It causes Blue Mold of apples, one of the most prevalent and economically damaging post-harvest diseases of apples.

Many species of fungi produce secondary metabolites called mycotoxins. These toxins can be very detrimental to both humans and animals. The side-effects of ingesting these toxic substances are called mycotoxicosis, which can be a variety of medical conditions. The most common fungi that produce mycotoxins include Fusarium, Aspergillus, and Penicillium.

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.

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

Aspergillus candidus is a white-spored species of fungus in the genus Aspergillus. Despite its lack of pigmentation, it is closely related to the most darkly-pigmented aspergilli in the Aspergillus niger group. It is a common soil fungus worldwide and is known as a contaminant of a wide array of materials from the indoor environment to foods and products. It is an uncommon agent of onychomycosis and aspergillosis. The species epithet candidus (L.) refers to the white pigmentation of colonies of this fungus. It is from the Candidi section. The fungi in the Candidi section are known for their white spores. It has been isolated from wheat flour, djambee, and wheat grain.

Penicillium nordicum is an anamorph species of fungus in the genus Penicillium which produces ochratoxin A. Penicillium nordicum contaminates protein rich foods and foods with high NaCl-konzentration. It is mostly found on dry-cured meat products and cheese products

<i>Penicillium digitatum</i> Species of fungus

Penicillium digitatum is a mesophilic fungus found in the soil of citrus-producing areas. It is a major source of post-harvest decay in fruits and is responsible for the widespread post-harvest disease in Citrus fruit known as green rot or green mould. In nature, this necrotrophic wound pathogen grows in filaments and reproduces asexually through the production of conidiophores and conidia. However, P. digitatum can also be cultivated in the laboratory setting. Alongside its pathogenic life cycle, P. digitatum is also involved in other human, animal and plant interactions and is currently being used in the production of immunologically based mycological detection assays for the food industry.

<i>Trichothecium roseum</i> Species of fungus

Trichothecium roseum is a fungus in the division Ascomycota first reported in 1809. It is characterized by its flat and granular colonies which are initially white and develop to be light pink in color. This fungus reproduces asexually through the formation of conidia with no known sexual state. Trichothecium roseum is distinctive from other species of the genus Trichothecium in its characteristic zigzag patterned chained conidia. It is found in various countries worldwide and can grow in a variety of habitats ranging from leaf litter to fruit crops. Trichothecium roseum produces a wide variety of secondary metabolites including mycotoxins, such as roseotoxins and trichothecenes, which can infect and spoil a variety of fruit crops. It can act as both a secondary and opportunistic pathogen by causing pink rot on various fruits and vegetables and thus has an economical impact on the farming industry. Secondary metabolites of T. roseum, specifically Trichothecinol A, are being investigated as potential anti-metastatic drugs. Several agents including harpin, silicon oxide, and sodium silicate are potential inhibitors of T. roseum growth on fruit crops. Trichothecium roseum is mainly a plant pathogen and has yet to show a significant impact on human health.

Penicillium viridicatum is a psychrophilic species of fungus in the genus, penicillic acid and citrinin. Penicillium viridicatum can spoil grapes and melons.

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

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.

Penicillium commune is an indoor fungus belonging to the genus Penicillium. It is known as one of the most common fungi spoilage moulds on cheese. It also grows on and spoils other foods such as meat products and fat-containing products like nuts and margarine. Cyclopiazonic acid and regulovasine A and B are the most important mycotoxins produced by P. commune. The fungus is the only known species to be able to produce both penitrem A and roquefortine. Although this species does not produce penicillin, it has shown to have anti-pathogenic activity. There are no known plant, animal or human diseases caused by P. commune.

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

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.

<i>Penicillium spinulosum</i> Species of fungus

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.

References

  1. 1 2 3 4 "Penicillium verrucosum". MycoBank Database. Retrieved 7 October 2016.
  2. 1 2 Stoll, D.A.; Geisen, R.; Schmidt-Heydt, M. "Whole Genome Shotgun Sequencing of Penicillium verrucosum reveals about 42 secondary metabolite gene clusters".{{cite web}}: Missing or empty |url= (help)
  3. 1 2 "Penicillium verrucosum Dierckx". MycoBank Database. Retrieved 13 October 2016.
  4. 1 2 3 4 5 6 7 Cabanes, Francisco Javier; Bragulat, Maria Rosa; Castella, Gemma (2010). "Ochratoxin A producing species in the Genus Penicillium". Toxins. 2 (5): 1111–1120. doi: 10.3390/toxins2051111 . PMC   3153233 . PMID   22069629.
  5. ↑ Raper, K.B.; Thom, C. (1949). A manual of the penicillia. Baltimore: The Williams & Wilkins Co.
  6. 1 2 Pitt, John (1987). "Penicillium viridicatum, Penicillium verrucosum, and production of ochratoxin A". Applied and Environmental Microbiology. 53 (2): 266–269. Bibcode:1987ApEnM..53..266P. doi:10.1128/aem.53.2.266-269.1987. PMC   203649 . PMID   3566267.
  7. 1 2 3 4 5 6 7 8 International Society for Human and Animal Mycology (1994). Journal of Medical and Veterinary Mycology, Volume 32, Supplement 1. Oxford, UK: Blackwell Scientific Publications.
  8. 1 2 3 4 5 6 Domsch, K.H.; Gams, Walter; Andersen, Traute-Heidi (1980). Compendium of soil fungi (2nd ed.). London, UK: Academic Press. ISBN   9780122204029.
  9. 1 2 3 Kozakiewicz, Z. "Penicillium verrucosum". CABI Bioscience. Retrieved 13 October 2016.
  10. 1 2 3 4 5 Lawley, Richard. "Ochratoxins". Food Safety Watch. Retrieved 7 November 2016.
  11. 1 2 3 4 5 6 7 8 Pitt, J.I.; Hocking, A.D. (1999). Fungi and food spoilage (2nd ed.). Gaithersburg, Md.: Aspen Publications. ISBN   978-0834213067.
  12. 1 2 3 4 Samson, Robert A.; Hoekstra, Ellen S.; Frisvad, Jens C. (2004). Introduction to food- and airborne fungi (7th ed.). Washington, DC: ASM Press. ISBN   978-9070351526.
  13. ↑ Rippon, John Willard (1988). Medical mycology: the pathogenic fungi and the pathogenic actinomycetes (3rd ed.). Philadelphia, PA: Saunders. ISBN   978-0721624440.
  14. 1 2 3 4 Pfohl-Leszkowicz, Annie; Manderville, Richard (2007). "Ochratoxin A: An overview on toxicity and carcinogenicity in animals and humans". Molecular Nutrition & Food Research. 51 (1): 61–99. doi:10.1002/mnfr.200600137. PMID   17195275.
  15. 1 2 3 Czaban, Janusz; Wroblewska, Barbara; Stochmal, Anna; Janda, Bogdan (2006). "Growth of Penicillium verrucosum and production of ochratoxin A on nonsterilized wheat grain incubated at different temperatures and water content". Polish Journal of Microbiology. 55 (4): 321–31. PMID   17416069.
  16. ↑ Cairns-Fuller, V; Aldred, D; Magan, N (2005). "Water, temperature and gas composition interactions affect growth and ochratoxin A production by isolates of Penicillium verrucosum on wheat grain". Journal of Applied Microbiology. 99 (5): 1215–21. doi:10.1111/j.1365-2672.2005.02695.x. PMID   16238752. S2CID   5950806.
  17. 1 2 3 4 5 6 Abrunhosa, Luis; Paterson, Robert; Venancio, Armando (2010). "Biodegradation of Ochratoxin A for Food and Feed Decontamination". Toxins. 2 (5): 1078–1099. doi: 10.3390/toxins2051078 . PMC   3153227 . PMID   22069627.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.