penicillium

American  

[pen-uh-sil-ee-uhm] / ˌpɛn əˈsɪl i əm /

noun

plural

penicilliums, penicillia

1. any fungus of the genus Penicillium, certain species of which are used in cheesemaking and as the source of penicillin.

---

penicillium British  

/ ˌpɛnɪˈsɪlɪəm /

noun

1. any ascomycetous saprotrophic fungus of the genus Penicillium, which commonly grow as a green or blue mould on stale food: some species are used in cheese-making and others as a source of penicillin

---

penicillium Scientific  

/ pĕn′ĭ-sĭl′ē-əm /

plural

penicilliums

1. Any of various bluish-green fungi of the genus Penicillium, that grow as molds on decaying fruits, ripening cheeses, and bread, and are used to produce penicillin and certain other antibiotics.

---

Etymology

Origin of penicillium

1925–30; < New Latin, equivalent to Latin pēnicill ( us ) brush ( pencil ) + -ium -ium

Example Sentences

Testing revealed the most common species was penicillium chrysogenum, famous because it is used to produce the penicillin antibiotic but it can cause allergic reactions or infections in people with compromised immune systems.

From BBC • Mar. 19, 2026

He eventually found what he was looking for: a strain of penicillium, or blue mold, that, in chickens, reduced levels of an enzyme that cells need to make LDL cholesterol.

From New York Times • Jun. 12, 2024

But the partnership also found new strains of the penicillium mold, and new methods of culturing it that vastly increased the yield of penicillin.

From Slate • Jul. 20, 2020

A canonical example is the discovery by Alexander Fleming, in 1928, that penicillium mold produces an antibiotic.

From Scientific American • Jul. 22, 2014

Contrary to this perfectly gratuitous assertion of M. Trecul's we do not keep our yeast in media which are calculated to prevent its transformation into penicillium.

From The Harvard Classics Volume 38 Scientific Papers (Physiology, Medicine, Surgery, Geology) by Various