Toxin Production by Stachybotrys chartarum Genotype S on Different Culture Media

Abstract

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 °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.

Production of Satratoxin G and H Is Tightly Linked to Sporulation in Stachybotrys chartarum

“…Reliable protocols are needed to determine the ability of individual isolates to produce MT and thereby evaluate their hazard potential. Apart from cellulosecontaining media, potato dextrose agar (PDA) was shown to be an excellent medium for MT production [27], but the nutritional factors that govern MT production have not been identified yet. Temperature and humidity have been shown to influence MT production, but the underlying mechanisms and regulatory genes are still unknown [6,28,29].…”

Testing the Toxicity of Stachybotrys chartarum in Indoor Environments—A Case Study

“…Studies by other authors [63] have shown the effect of the culture medium on the production of Stachybotrys chartarum mycotoxins. The highest concentrations of macrocyclic trichothecenes were determined on the PDA medium; the MEA medium was the intermediate medium.…”

Biomonitoring of Indoor Air Fungal or Chemical Toxins with Caenorhabditis elegans nematodes

“…By contrast, Penicillium family members are fairly common in all types of buildings, and only some of them produce toxins [ 49 , 50 ], explaining the variable responses we observed. In addition, it should be noted that mycotoxin production depends on the metabolic activity and growth phase of fungi, so not even the pathogenic species produce toxins all the time, but only under certain conditions [ 51 ].…”