Species-specific profiles of mycotoxins produced in cultures and associated with conidia of airborne fungi derived from biowaste

The potential to produce mycotoxins and non-volatile secondary metabolites was investigated for approximately 250 freshly isolated fungal strains. Among the eleven most relevant species, viz. Aspergillus flavus, A. fumigatus, A. niger, A. parasiticus, A. versicolor, Emericella nidulans, Paecilomyces variotii, Penicillium brevicompactum, P. clavigerum, P. crustosum, and P. polonicum, a wide range of metabolites partly of toxicological relevance was identified. Several unknown metabolites were found for the less frequent species, which were primarily investigated for chemotaxonomic delimitation from closely related species. The spectra of metabolites in conidial extracts and culture extracts (containing also mycelium and medium) were compared for a limited number of relevant fungi. Some mycotoxins, such as sterigmatocystin in Emericella nidulans, were not present in the conidial extracts, though produced by most strains. Fumigaclavine C, tryptoquivaline, and trypacidin, characteristic for A. fumigatus, were found in conidial extracts, but highly toxic compounds such as gliotoxin and fumitremorgens were not present. Finally, compounds such as cyclopenol, cyclopenin, and penitrem A being characteristic for certain penicillia, were found in conidial extracts and are therefore assumed to occur in native bioaerosols.