Considering the incidence of particular species of fungi, most frequently isolated on infected surfaces were: Aspergillus versicolor, Cladosporium cladosporioides, Penicillium chrysogenum, Ulocladium chartarum and Acremonium charticola.
While assessing the toxinogenicity of individual strains of Aspergillus versicolor cultured on the medium, the production of sterigmatocystin ranging 2.1-235.9 [micro]g/g was confirmed in conditions similar to the conditions prevailing in the tested flats for 8 of 13 isolated strains, while for Penicillium chrysogenum the production of roquefortine C ranging 12.9-27.6 [micro]g/g was confirmed for 4 of 10 isolated strains.
Piontek isolated from building materials and other moldy surfaces 22 strains of Aspergillus versicolor, of which 19 in laboratory conditions synthesized sterigmatocystin at 0.03-534.38 mg/kg .
Sterigmatocystin, produced by molds of Aspergillus genus (mainly Aspergillus versicolor species) is a toxic secondary metabolite whose structure resembles that of aflatoxin, a precursor of its biosynthesis [21,54].
This confirms that the strains of Aspergillus versicolor and Penicillium chrysogenum classified as toxinogenic exhibit this property in laboratory conditions when cultured on MEA medium.
The research confirmed the occurrence, on the tested surfaces, of strains of Aspergillus versicolor genus which can produce sterigmatocystin and strains of Penicillium chrysogenum genus capable of producing roquefortine C.
We selected Aspergillus versicolor and Stachybotrys chartarum because of their characteristic occurrence in moldy indoor environments and because of their importance as potential toxin producers.
In this study we used three fungal strains, Aspergillus versicolor, Penicillium spinulosum, and Stachybotrys chartarum, and three bacterial strains, Bacillus cereus, Pseudomonas fluorescens, and Streptomyces californicus.
The cytotoxicity of fungi decreased in the order Stachybotrys chartarum > Aspergillus versicolor > Penicillium spinulosum, but it did not differ notably from the cytotoxicity of bacteria.