Penicillium roqueforti

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.

Penicillium roqueforti
Blue Stilton cheese, showing the blue-green mold veins produced by Penicillium roqueforti
Scientific classification Edit this 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[4]
  • Penicillium roqueforti var. weidemannii Westling (1911)[1]
  • Penicillium weidemannii (Westling) Biourge (1923)[2]
  • Penicillium gorgonzolae Weid. (1923)
  • Penicillium roqueforti var. viride Datt.-Rubbo (1938)[3]
  • Penicillium roqueforti var. punctatum S.Abe (1956)
  • Penicillium conservandi Novobr. (1974)

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.

Classification

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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]

Description

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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.

Uses

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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.

Secondary metabolites

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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]

See also

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References

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  1. ^ Westling R. (1911). "Über die grünen Spezies der Gattung Penicillium". Arkiv før Botanik (in German) (1): 71.
  2. ^ Biourge P. (1923). "Les moissisures du groupe Penicillium Link". La Cellule (in French). 33: 7–331 (see pp. 203–4).
  3. ^ Dattilo-Rubbo S. (1938). "The taxonomy of fungi of blue-veined cheese". Transactions of the British Mycological Society. 22 (1–2): 174–81. doi:10.1016/s0007-1536(38)80015-2.
  4. ^ "GSD Species Synonymy: Penicillium roqueforti Thom". Species Fungorum. CAB International. Archived from the original on 10 March 2021. Retrieved 27 May 2015.
  5. ^ Thom C. (1909). "Fungi in cheese ripening; Camembert and Roquefort". U.S.D.A. Bureau of Animal Industry Bulletin. 82: 1–39 (see p. 36).
  6. ^ Boysen M, Skouboe P, Frisvad J, Rossen L (1996). "Reclassification of the Penicillium roqueforti group into three species on the basis of molecular genetic and biochemical profiles". Microbiology. 142 (3): 541–9. doi:10.1099/13500872-142-3-541. PMID 8868429.
  7. ^ Cheeseman K, Ropars J, Renault P, et al. (2014). "Multiple recent horizontal transfers of a large genomic region in cheese making fungi". Nature Communications. 5: 2876. Bibcode:2014NatCo...5.2876C. doi:10.1038/ncomms3876. PMC 3896755. PMID 24407037.
  8. ^ O'brien M, Egan D, O'kiely P, Forristal PD, Doohan FM, Fuller HT (August 2008). "Morphological and molecular characterisation of Penicillium roqueforti and P. paneum isolated from baled grass silage". Mycol. Res. 112 (Pt 8): 921–32. doi:10.1016/j.mycres.2008.01.023. PMID 18554890.
  9. ^ Raper KB, Alexander DF, Coghill RD (December 1944). "Penicillin: II. Natural Variation and Penicillin Production in Penicillium notatum and Allied Species". J. Bacteriol. 48 (6): 639–59. doi:10.1128/JB.48.6.639-659.1944. PMC 374019. PMID 16560880.
  10. ^ Raper KB (1957). "Nomenclature in Aspergillus and Penicillium". Mycologia. 49 (5): 644–662. doi:10.2307/3755984. JSTOR 3755984.
  11. ^ Samson RA, Gams W (1984). "The taxonomic situation in the hyphomycete genera Penicillium, Aspergillus and Fusarium". Antonie van Leeuwenhoek. 50 (5–6): 815–24. doi:10.1007/BF02386244. PMID 6397143. S2CID 7084024.
  12. ^ Ropars J, Dupont J, Fontanillas E, Rodríguez de la Vega RC, Malagnac F, Coton M, Giraud T, López-Villavicencio M (2012). "Sex in cheese: evidence for sexuality in the fungus Penicillium roqueforti". PLOS ONE. 7 (11): e49665. Bibcode:2012PLoSO...749665R. doi:10.1371/journal.pone.0049665. PMC 3504111. PMID 23185400.
  13. ^ Ropars J, López-Villavicencio M, Dupont J, Snirc A, Gillot G, Coton M, Jany JL, Coton E, Giraud T (2014). "Induction of sexual reproduction and genetic diversity in the cheese fungus Penicillium roqueforti ". Evolutionary Applications. 7 (4): 433–41. Bibcode:2014EvApp...7..433R. doi:10.1111/eva.12140. PMC 4001442. PMID 24822078.  
  14. ^ Kinsella JE, Hwang DH (November 1976). "Enzymes of Penicillium roqueforti involved in the biosynthesis of cheese flavour". Crit Rev Food Sci Nutr. 8 (2): 191–228. doi:10.1080/10408397609527222. PMID 21770.
  15. ^ Zafer Erbay; Pelin Salum; Kieran N. Kilcawley (2021). "Enzyme Modified Cheese". Agents of Change: Enzymes in Milk and Dairy Products. Food Engineering Series. doi:10.1007/978-3-030-55482-8. ISBN 978-3-030-55481-1. S2CID 231671267.
  16. ^ Raines, Jason (1 August 2012). Factors Affecting the Production of Concentrated Blue Cheese Flavorings (MSc). Clemson University.
  17. ^ (Sharpell, 1985)
  18. ^ Möller, T.; Akerstrand, K.; Massoud, T. (1997). "Toxin-producin species of Penicillium and the development of mycotoxins in must and homemade wine". Nat. Toxins. 5 (2): 86–9. doi:10.1002/(SICI)(1997)5:2<86::AID-NT6>3.0.CO;2-7. PMID 9131595.
  19. ^ Finoli C, Vecchio A, Galli A, Dragoni I (February 2001). "Roquefortine C occurrence in blue cheese". Journal of Food Protection. 64 (2): 246–51. doi:10.4315/0362-028x-64.2.246. PMID 11271775.
  20. ^ a b Erdogan A, Sert S (March 2004). "Mycotoxin-forming ability of two Penicillium roqueforti strains in blue moldy tulum cheese ripened at various temperatures". Journal of Food Protection. 67 (3): 533–5. doi:10.4315/0362-028X-67.3.533. PMID 15035369.
  21. ^ O'Brien M, Nielsen KF, O'Kiely P, Forristal PD, Fuller HT, Frisvad JC (November 2006). "Mycotoxins and other secondary metabolites produced in vitro by Penicillium paneum Frisvad and Penicillium roqueforti Thom isolated from baled grass silage in Ireland" (PDF). Journal of Agricultural and Food Chemistry. 54 (24): 9268–76. doi:10.1021/jf0621018. PMID 17117820. S2CID 8916694.
  22. ^ Proctor RH, Hohn TM (February 1993). "Aristolochene synthase. Isolation, characterization, and bacterial expression of a sesquiterpenoid biosynthetic gene (Ari1) from Penicillium roqueforti". Journal of Biological Chemistry. 268 (6): 4543–8. doi:10.1016/S0021-9258(18)53644-9. PMID 8440737. Archived from the original on 25 September 2019. Retrieved 3 December 2008.
  23. ^ Chen FC, Chen CF, Wei RD (1982). "Acute toxicity of PR toxin, a mycotoxin from Penicillium roqueforti". Toxicon. 20 (2): 433–41. Bibcode:1982Txcn...20..433C. doi:10.1016/0041-0101(82)90006-X. PMID 7080052.
  24. ^ Siemens, Zawitowski J (1993). "Occurrence of PR imine, a metabolite of Penicillium roqueforti, in blue cheese". Journal of Food Protection. 56 (4): 317–319. doi:10.4315/0362-028X-56.4.317. PMID 31091623.
  25. ^ Nielsen KF, Dalsgaard PW, Smedsgaard J, Larsen TO (April 2005). "Andrastins A-D, Penicillium roqueforti Metabolites consistently produced in blue-mold-ripened cheese". Journal of Agricultural and Food Chemistry. 53 (8): 2908–13. doi:10.1021/jf047983u. PMID 15826038.
  26. ^ SCBT. "Roquefortine - A potent neurotoxin produced most notably by Penicillium species". Archived from the original on 16 March 2016. Retrieved 17 May 2013. {{cite journal}}: Cite journal requires |journal= (help)
  27. ^ "Penicillium roqueforti Final Risk Assessment". United States Environmental Protection Agency. 29 April 2015. Archived from the original on 24 September 2015. Retrieved 17 May 2013.
  28. ^ Larroche C, Arpah M, Gros JB (1989). "Methyl-ketone production by Ca-alginate/Eudragit RL entrapped spores of Penicillium roqueforti". Enzyme and Microbial Technology. 11 (2): 106–112. doi:10.1016/0141-0229(89)90068-9.
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This article is based on text originally from a report of the United States Environmental Protection Agency.