Penicillium roqueforti | |
---|---|
Blue Stilton cheese, showing the blue-green mold veins produced by Penicillium roqueforti | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Eurotiomycetes |
Order: | Eurotiales |
Family: | Aspergillaceae |
Genus: | Penicillium |
Species: | P. roqueforti |
Binomial name | |
Penicillium roqueforti Thom (1906) | |
Synonyms [1] | |
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.
The major industrial use of this fungus is the production of blue cheeses, flavouring agents, antifungals, polysaccharides, proteases, and other enzymes. The fungus has been a constituent of Roquefort, Stilton, Danish blue, Cabrales, and other blue cheeses. Other blue cheeses, such as Gorgonzola, are made with Penicillium glaucum .
First described by American mycologist Charles Thom in 1906, [5] P. roqueforti was initially a heterogeneous species of blue-green, sporulating fungi. They were grouped into different species based on phenotypic differences, but later combined into one species by Kenneth B. Raper and Thom (1949). The P. roqueforti group got a reclassification in 1996 due to molecular analysis of ribosomal DNA sequences. Formerly divided into two varieties―cheese-making (P. roqueforti var. roqueforti) and patulin-making (P. roqueforti var. carneum)―P. roqueforti was reclassified into three species: P. roqueforti, P. carneum , and P. paneum . [6] The complete genome sequence of P. roqueforti was published in 2014. [7]
As this fungus does not form visible fruiting bodies, descriptions are based on macromorphological characteristics of fungal colonies growing on various standard agar media, and on microscopic characteristics. When grown on Czapek yeast autolysate agar or yeast-extract sucrose (YES) agar, P. roqueforti colonies are typically 40 mm in diameter, olive brown to dull green (dark green to black on the reverse side of the agar plate), with a velutinous texture. Grown on malt extract agar, colonies are 50 mm in diameter, dull green in color (beige to greyish green on the reverse side), with arachnoid (with many spider-web-like fibers) colony margins. [8] Another characteristic morphological feature of this species is its production of asexual spores in phialides with a distinctive brush-shaped configuration. [9] [10] [11]
Evidence for a sexual stage in P. roqueforti has been found, based in part on the presence of functional mating-type genes and most of the important genes known to be involved in meiosis. [12] In 2014, researchers reported inducing the growth of sexual structures in P. roqueforti, including ascogonia, cleistothecia, and ascospores. Genetic analysis and comparison of many different strains isolated from various environments around the world indicate that it is a genetically diverse species. [13]
P. roqueforti can tolerate cold temperatures, low oxygen levels, and both alkali and weaker acid preservatives which allows the fungi to thrive and be found in dairy environments, such as cheese. On the other hand, it also spoils refrigerated foods and meats, breads, and silage.
The chief industrial use of this species is the production of blue cheeses, such as its namesake Roquefort, [14] Bleu de Bresse, Bleu du Vercors-Sassenage, Brebiblu, Cabrales, Cambozola (Blue Brie), Cashel Blue, Danish blue, Swedish Ädelost, Polish Rokpol made from cow's milk, Fourme d'Ambert, Fourme de Montbrison, Lanark Blue, Shropshire Blue, and Stilton, and some varieties of Bleu d'Auvergne and Gorgonzola. (Other blue cheeses, including Bleu de Gex and Rochebaron, use Penicillium glaucum .)
When placed into cream and aerated, P. roqueforti produces concentrated blue cheese flavoring, a type of enzyme-modified cheese. [15] A similar flavoring can be produced using other sources of fatty acids such as coconut oil. [16]
Strains of the microorganism are also used to produce compounds that can be employed as antibiotics, flavours, and fragrances, [17] uses not regulated under the U.S. Toxic Substances Control Act. Its texture is chitinous.
Considerable evidence indicates that most strains are capable of producing harmful secondary metabolites (alkaloids and other mycotoxins) under certain growth conditions. [18] [19] [20] [21] Aristolochene is a sesquiterpenoid compound produced by P. roqueforti, and is likely a precursor to the toxin known as PR toxin, made in large amounts by the fungus. [22] PR-toxin has been implicated in incidents of mycotoxicoses resulting from eating contaminated grains. [20] [23] However, PR toxin is not stable in cheese and breaks down to the less toxic PR imine. [24]
Secondary metabolites of P. roqueforti, named andrastins A–D, are found in blue cheese. The andrastins inhibit proteins involved in the efflux of anticancer drugs from multidrug-resistant cancer cells. [25]
P. roqueforti also produces the neurotoxin roquefortine C. [26] [27] However, the levels of roquefortine C in cheese made from it is usually too low to produce toxic effects. The organism can also be used for the production of proteases and specialty chemicals, such as methyl ketones, including 2-heptanone. [28]
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.
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.
Blue cheese is any of a wide range of cheeses made with the addition of cultures of edible molds, which create blue-green spots or veins through the cheese. Blue cheeses vary in taste from very mild to strong, and from slightly sweet to salty or sharp; in colour from pale to dark; and in consistency from liquid or very soft to firm or hard. They may have a distinctive smell, either from the mold or from various specially cultivated bacteria such as Brevibacterium linens.
Penicillium camemberti is a species of fungus in the genus Penicillium. It is used in the production of Camembert, Brie, Langres, Coulommiers, and Cambozola cheeses, on which colonies of P. camemberti form a hard, white crust. It is responsible for giving these cheeses their distinctive flavors. An allergy to the antibiotic penicillin does not necessarily imply an allergy to cheeses made using P. camemberti.
Penicillium crustosum is a blue-green or blue-grey mold that can cause food spoilage, particularly of protein-rich foods such as meats and cheeses. It is identified by its complex biseriate conidiophores on which phialides produce asexual spores. It can grow at fairly low temperatures, and in low water activity environments.
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.
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.
Aristolochene is a bicyclic sesquiterpene produced by certain fungi including the cheese mold Penicillium roqueforti. It is biosynthesized from farnesyl pyrophosphate by aristolochene synthase and is the parent hydrocarbon of a large variety of fungal toxins.
Roquefortine C is a mycotoxin that belongs to a class of naturally occurring 2,5-diketopiperazines produced by various fungi, particularly species from the genus Penicillium. It was first isolated from a strain of Penicillium roqueforti, a species commercially used as a source of proteolytic and lipolytic enzymes during maturation of the blue-veined cheeses, Roquefort, Danish Blue, Stilton and Gorgonzola.
Penicillium chrysogenum is a species of fungus in the genus Penicillium. It is common in temperate and subtropical regions and can be found on salted food products, but it is mostly found in indoor environments, especially in damp or water-damaged buildings. It has been recognised as a species complex that includes P. notatum, P. meleagrinum, and P. cyaneofulvum. Molecular phylogeny has established that Alexander Fleming's first discovered penicillin producing strain is of a distinct species, P. rubens, and not of P. notatum. It has rarely been reported as a cause of human disease. It is the source of several β-lactam antibiotics, most significantly penicillin. Other secondary metabolites of P. chrysogenum include roquefortine C, meleagrin, chrysogine, 6-MSA YWA1/melanin, andrastatin A, fungisporin, secalonic acids, sorbicillin, and PR-toxin.
Penicillium carneum is a fungus species of the genus of Penicillium.Penicillium roqueforti var. carneum was reclassified to Penicillium carneum.P. carneum was isolated from spoiled meat products, silage, rye bread, water, beer, cheese, mouldy barkers yeast and cork. P. carneum produces patulin, penicillic acid, penitrem A, mycophenolic acid roquefortines.
Penicillium psychrosexualis is a filamentous fungus in the genus Penicillium. Described as new to science in 2010, the species was found growing on refrigerated moldy apples in the Netherlands. It is closely related to the blue cheese fungus P. roqueforti.
Penicillium paneum is a species of fungus in the genus Penicillium which can spoil cereal grains. Penicillium paneum produces 1-Octen-3-ol and penipanoid A, penipanoid B, penipanoid C, patulin and roquefortine C
Penicillium polonicum is a species of fungus in the genus Penicillium which produces penicillic acid, verucosidin, patulin, anacine, 3-methoxyviridicatin and glycopeptides. Penicillium polonicum can spoil cereals, peanuts, onions, dried meats, citrus fruits
Penicillium solitum is an anamorphic, mesophilic, salinity-tolerant, and psychrotolerant species of fungus in the genus Penicillium. It is known to produce various compounds including polygalacturonase, compactin, cyclopenin, cyclopenol, cyclopeptin, dehydrocompactin, dihydrocyclopeptin, palitantin, solistatin, solistatinol, viridicatin, viridicatol.
Penicillium tulipae is a species of fungus in the genus Penicillium which produces penicillic acid, roquefortine C, roquefortine D, terrestric acid, glandicoline A, glandicoline B, meleagrin, oxaline, penitrem A and epineoxaline.
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.
Aspergillus brevipes is an anamorph species of fungus in the genus Aspergillus. It is from the Fumigati section. It was first described in 1952. It has been isolated from soil in Australia. Aspergillus brevipes produces roquefortine C, meleagrin and viriditoxin.
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.
Penicillin Roquefort toxin is a mycotoxin produced by the fungi Penicillium roqueforti. In 1973, PR toxin was first partially characterized by isolating moldy corn on which the fungi had grown. Although its lethal dose was determined shortly after the isolation of the chemical, details of its toxic effects were not fully clarified until 1982 in a study with mice, rats, anesthetized cats and preparations of isolated rat auricles.
{{cite journal}}
: Cite journal requires |journal=
(help)