Colonies on 2% malt extract agar are spreading, woolly, whitish to pale greyish-brown, soon forming macroscopically visible fruiting bodies. Although some isolates may take up to 12 weeks to form fruiting bodies. Fruit bodies are sessile, kidney-shaped, lobed with split gills on the lower side. Hyphae are hyaline, wide and have clamp connections (although many primary clinical isolates are monokaryotic and will therefore not produce clamp connections). Basidia bear 4 basidiospores on erect sterigmata. Basidiospores hyaline, smooth-walled, elongate with lateral scar at lower end, 6-7 x 2-3 µm.
Note: many clinical isolates of S. commune are monokaryotic and therefore do not show clamp connections, therefore any white, rapidly growing, sterile isolate showing good growth at 37C with tolerance to benomyl, susceptibility to cycloheximide, and a pronounced odour should be suspected of being S. commune (Sigler et al., 1995).
Basidiocarps of Schizophyllum commune on malt extract agar.
Shizophyllum is a common bracket fungus on rotten wood, and is an occasional human pathogen, principally associated with sinusitis, allergic bronchopulmonary mycosis and as a contaminant from respiratory specimens. RG-1 organism.