Home • Monascus ruber NRRL 1597 v1.0
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Monascus ruber van Tiegh. (A) Colony surface on PDA showing characteristic pigmentation. (B) Colony reverse on PDA showing reddish to brownish pigment in medium. (C) Young cleistothecium. (D) Mature cleistothecium filled with ellipsoidal ascospores. (C and D credit R. A. Samson, CBS-KNAW Fungal Biodiversity Centre, Utrecht, the Netherlands)

Monascus ruber NRRL 1597 (Pezizomycotina, Eurotiomycetes) was selected as part of the 1000 Fungal Genomes CSP to represent a member of the ascomycete family Monascaceae. Monascus species are best known for their use in fermented Asian foods such as rice wine and red rice (also known as ang-kak and beni-koji) and as a food colorant (Pitt and Hocking, 2009). However, subsequent to the discovery that Monascus produces the nephrotoxic and hepatotoxic mycotoxin citrinin (Chen et al., 2008), its use as a food colorant within the US and Europe was discontinued. While it is still used to color traditional fermented foods with red yeast rice in Asia, citrinin levels are rigorously monitored. Monascus ruber produces lovastatin, but strains of Aspergillus terreus are typically used in the industrial production of this anticholesterolemic (Patakova, 2012).

Young colonies on potato dextrose agar (PDA) are floccose and white with pink tinges and they produce reddish to brown pigments that diffuse into the medium. With age the self-fertile colonies turn brown to orange brown as stalked, spherical ascomata (cleistothecia) 30 to 70 μm in diameter are produced from a stalked terminal vesicle. Hyphae that grow from the base of the ascomata eventually enclose the cleistothecia with a brown wall. Globose asci produced within each cleistothecium soon evanesce resulting in it becoming filled with ellipsoidal ascospores. Colonies also produce terminal chains of subglobose conidia aleuroconidia.


Chen, Y.-P., et al., 2008. Exploring the distribution of citrinin biosynthesis related genes among Monascus species. J. Agri. Food Chem. 56, 11767-11772.

Patakova, P., 2012. Monascus secondary metabolites: production and biological activity. J. Ind. Microbiol. Biotechnol. DOI 10.1007/s10295-012-1216-8.

Pitt, J.I., Hocking, A.A.D., 2009. Fungi and Food Spoilage (3rd edition). Springer, New York.