Stachybotrys (S.) chartarum had been linked to severe health problems in humans and
animals, which occur after exposure to the toxic secondary metabolites of this mold.
S. chartarum had been isolated from different environmental sources, ranging from
culinary herbs and improperly stored fodder to damp building materials. To access
the pathogenic potential of isolates, it is essential to analyze them under defined
conditions that allow for the production of their toxic metabolites. All Stachybotrys
species are assumed to produce the immunosuppressive phenylspirodrimanes, but the
highly cytotoxic macrocyclic trichothecenes are exclusively generated by the genotype
S of S. chartarum. In this study, we have analyzed four genotype S strains initially
isolated from three different habitats. We grew them on five commonly used media (malt-extract-agar,
glucose-yeast-peptone-agar, potato-dextrose-agar, cellulose-agar, Sabouraud-dextrose-agar)
to identify conditions that promote mycotoxin production. Using LC-MS/MS, we have
quantified stachybotrylactam and all S-type specific macrocyclic trichothecenes (satratoxin
G, H, F, roridin E, L-2, verrucarin J). All five media supported a comparable fungal
growth and sporulation at 25 degrees C in the dark. The highest concentrations of
macrocyclic trichothecenes were detected on potato-dextrose-agar or cellulose-agar.
Malt-extract-agar let to an intermediate and glucose-yeast-peptone-agar and Sabouraud-dextrose-agar
to a poor mycotoxin production. These data demonstrate that the mycotoxin production
clearly depends on the composition of the respective medium. Our findings provide
a starting point for further studies in order to identify individual components that
either support or repress the production of mycotoxins in S. chartarum.