Introduction to Fungi, Third Edition

EUROTIALES
311
Fig11.18 Conidiophores of the four anamorphic subgenera of Penicillium.(a)Penicillium spinulosum (subgenus Aspergilloides).
(b) Penicillium verruculosum (subgenus Biverticillium). (c) Penicillium citrinum (subgenus Furcatum), possibly ‘one of the most common
eukaryotic life forms on earth’ (Pitt,1979). (d) Penicillium expansum (subgenus Penicillium).
Aspergillus, there is evidence that the ability to
reproduce sexually has been lost on several independent
occasions in Penicillium (LoBuglio et al.,
1993).
Penicillium is one of the most ubiquitous
groups of fungi, occurring on all kinds of decaying
materials. The conidia are universally present
in air, so that Penicillium colonies are frequent
contaminants of cultures. It was such a chance
contaminant which led to the discovery of penicillin
(see p. 302). Penicillium italicum and
P. digitatum cause rotting of citrus fruits
(Plate 4e) whilst P. expansum causes a brown rot
of apples (see p. 304).
Fig11.19
plate.
Penicillium claviforme producing coremia on an agar
Eupenicillium
Members of the genus Eupenicillium produce
conidiophores which may be mono-, bi- or terverticillate.
The terverticillate species (subgenus
Penicillium) have been particularly well studied
because many of them are relevant to man as
producers of antibiotics (P. griseofulvum), in food
production (e.g. P. camemberti and P. roqueforti) or