About Penicillium sclerotiorum
Penicillium sclerotiorum is a pigmented Penicillium producing the orange-yellow azaphilone sclerotiorin. Most isolations are from soil and decaying plant material; indoor occurrences are uncommon. The species is offered on extended panels for taxonomic completeness within the genus.
Taxonomy
Penicillium subgenus Furcatum
Ecology and habitat
P. sclerotiorum is globally distributed in soil and on decaying plant matter. The species is distinguished by sclerotiorin production, which gives colonies their characteristic colored appearance. Indoor isolations are uncommon.
Indoor relevance
P. sclerotiorum is rarely the dominant species in indoor dust panels. The species's mycotoxin signal is dominated by sclerotiorin and related azaphilones, which are bioactive but not major commercial-panel mycotoxin targets. On extended panels it is mainly of interest for taxonomic completeness rather than as a specific damp-building-material marker.
Cardinal physiology
Minimum water activity for growth: Aw 0.81[2]. Growth across 5–37 °C with optimum 25 °C. The species is broadly similar to other Penicillia in cardinal physiology.
Secondary metabolites
The principal metabolite is sclerotiorin, an azaphilone with documented bioactivity (cholesterol-related enzyme inhibition, anti-inflammatory effects in research contexts). Sclerotiorin is not a standard commercial mycotoxin assay target.
Compounds documented as produced by Penicillium sclerotiorum (presence and quantity vary by chemotype, strain, and substrate):
DNA-based detection of a mycotoxin-producing species in household dust does not directly establish exposure to that mycotoxin at any specific concentration.
Lab availability
Some commercial dust testing labs offer this species as an extended-panel option. Specific lab coverage changes over time: check with your laboratory for current panel options.