Artificial vs natural Stachybotrys infestation-Comparison of mycotoxin production on various building materials.

The genus Stachybotrys belongs to filamentous fungi found in indoor environment, mostly on cellulose-rich substrates after water-damage. The major purpose of this study was to investigate the influence of different building materials in case of mold infestation on the mycotoxin production of Stachybotrys species. Fifteen Stachybotrys mycotoxins including satratoxins, phenylspirodrimanes, and recently discovered stachybotrychromenes were in the focus of the investigations. Artificial and natural infestations were compared to determine whether environmental factors, for example, time of growth, temperature, humidity, and material additives have an influence on the observed mycotoxin profiles. It turned out that mycotoxin profiles from Stachybotrys spp. on building materials can be influenced by cellulose, paints, and paste of the materials. The total toxin levels of artificially and naturally contaminated gypsum board samples ranged up to 30 µg/cm2 , whereas wallpaper samples showed total toxin levels in the range of 20-66 µg/cm2 . A naturally infested sample disclosed the conversion of the dialdehyde components to the corresponding lactone isomers under the influence of light.