|Blue Stilton cheese, showing the blue-green mold veins produced by Penicillium roqueforti|
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, Gorgonzola, and other blue cheeses that humans are known to have eaten since around AD 50; blue cheese is mentioned in literature as far back as AD 79, when Pliny the Elder remarked upon its rich flavour.
First described by American mycologist Charles Thom in 1906, 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. The complete genome sequence of P. roqueforti was published in 2014.
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. Another characteristic morphological feature of this species is its production of asexual spores in phialides with a distinctive brush-shaped configuration.
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. 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.
The chief industrial use of this species is the production of blue cheeses, such as its namesake Roquefort, Bleu de Bresse, Bleu du Vercors-Sassenage, Brebiblu, Cabrales, Cambozola (Blue Brie), Cashel Blue, Danish blue, 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.)
Strains of the microorganism are also used to produce compounds that can be employed as antibiotics, flavours, and fragrances, 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. 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. PR-toxin has been implicated in incidents of mycotoxicoses resulting from eating contaminated grains. However, PR toxin is not stable in cheese and breaks down to the less toxic PR imine.
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.
P. roqueforti also produces the neurotoxin roquefortine C. 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.
- Westling R. (1911). "Über die grünen Spezies der Gattung Penicillium". Arkiv før Botanik (in German) (1): 71.
- Biourge P. (1923). "Les moissisures du groupe Penicillium Link". La Cellule (in French). 33: 7–331 (see pp. , 203–4).
- 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.
- "GSD Species Synonymy: Penicillium roqueforti Thom". Species Fungorum. CAB International. Retrieved 2015-05-27.
- Judy Ridgway (12 October 2004). The Cheese Companion. Running Press. p. 10. ISBN 978-0-7624-1956-2. Retrieved 2 February 2013.
- 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).
- 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.
- 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. doi:10.1038/ncomms3876. PMC 3896755. PMID 24407037.
- 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.
- 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. PMC 374019. PMID 16560880.
- Raper KB (1957). "Nomenclature in Aspergillus and Penicillium". Mycologia. 49 (5): 644–662. doi:10.2307/3755984. JSTOR 3755984.
- 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.
- 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. doi:10.1371/journal.pone.0049665. PMC 3504111. PMID 23185400.
- 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. doi:10.1111/eva.12140.
- Skaar I. (1996). Mycological survey and characterisation of the mycobiota of big bale grass silage in Norway. PhD thesis, Norwegian College of Veterinary Medicine, Oslo.
- Auerbach H, Oldenburg W, Weissbach F (2008). "Incidence of Penicillium roqueforti and roquefortine C in silages". Journal of the Science of Food and Agriculture. 76 (4): 565–572. doi:10.1002/(SICI)1097-0010(199804)76:4<565::AID-JSFA990>3.0.CO;2-6.
- Nielsen KF; M.W. Sumarah; Frisvad JC; Miller JD (2006). "Production of metabolites from the Penicillium roqueforti complex". Journal of Agricultural and Food Chemistry. 54 (10): 3756–3763. doi:10.1021/jf060114f. PMID 19127756.
- Mansfield MA, Kuldau GA (2007). "Microbiological and molecular determination of mycobiota in fresh and ensiled maize silage". Mycologia. 99 (2): 269–78. doi:10.3852/mycologia.99.2.269. PMID 17682779.
- Boysen ME, Jacobsson KG, Schnürer J (April 2000). "Molecular Identification of Species from the Penicillium roqueforti Group Associated with Spoiled Animal Feed". Appl. Environ. Microbiol. 66 (4): 1523–6. doi:10.1128/AEM.66.4.1523-1526.2000. PMC 92017. PMID 10742236.
- 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.
- (Sharpell, 1985)
- Möller, T.; Akerstrand, K.; Massoud, T. (1997). "Toxin-producing species ofPenicillium 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.
- Finoli C, Vecchio A, Galli A, Dragoni I (February 2001). "Roquefortine C occurrence in blue cheese". J. Food Prot. 64 (2): 246–51. doi:10.4315/0362-028x-64.2.246. PMID 11271775.
- Erdogan A, Sert S (March 2004). "Mycotoxin-forming ability of two Penicillium roqueforti strains in blue moldy tulum cheese ripened at various temperatures". J. Food Prot. 67 (3): 533–5. PMID 15035369.
- O'Brien M, Nielsen KF, O'Kiely P, Forristal PD, Fuller HT, Frisvad JC (November 2006). "Mycotoxins and other secondary metabolites produced in vitro byPenicillium paneum Frisvad and Penicillium roqueforti Thom isolated from baled grass silage in Ireland". J. Agric. Food Chem. 54 (24): 9268–76. doi:10.1021/jf0621018. PMID 17117820.
- Proctor RH, Hohn TM (February 1993). "Aristolochene synthase. Isolation, characterization, and bacterial expression of a sesquiterpenoid biosynthetic gene (Ari1) from Penicillium roqueforti". J. Biol. Chem. 268 (6): 4543–8. PMID 8440737. Retrieved 2008-12-03.
- Chen FC, Chen CF, Wei RD (1982). "Acute toxicity of PR toxin, a mycotoxin from Penicillium roqueforti". Toxicon. 20 (2): 433–41. doi:10.1016/0041-0101(82)90006-X. PMID 7080052. Retrieved 2008-12-03.
- Siemens , Zawitowski J (1993). "Occurrence of PR imine, a metabolite of Penicillium roqueforti, in blue cheese". Journal of Food Protection. 56 (4): 317–319.
- Nielsen KF, Dalsgaard PW, Smedsgaard J, Larsen TO (April 2005). "Andrastins A-D, Penicillium roqueforti Metabolites consistently produced in blue-mold-ripened cheese". J. Agric. Food Chem. 53 (8): 2908–13. doi:10.1021/jf047983u. PMID 15826038.
- SCBT. "Roquefortine - A potent neurotoxin produced most notably by Penicillium species".
- EPA. "Penicillium roqueforti Final Risk Assessment".
- 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.