Production of Satratoxin G and H Is Tightly Linked to Sporulation in <i>Stachybotrys chartarum</i>
Katharina Tribelhorn,
Magdalena Twarużek,
Ewelina Soszczyńska,
Jörg Rau,
Christiane Baschien,
Reinhard K. Straubinger,
Frank Ebel,
Sebastian Ulrich
Affiliations
Katharina Tribelhorn
Chair of Bacteriology and Mycology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Institute for Infectious Diseases and Zoonosis, LMU Munich, 80539 Munich, Germany
Magdalena Twarużek
Department of Physiology and Toxicology, Faculty of Biological Sciences, Kazimierz Wielki University, 85–064 Bydgoszcz, Poland
Ewelina Soszczyńska
Department of Physiology and Toxicology, Faculty of Biological Sciences, Kazimierz Wielki University, 85–064 Bydgoszcz, Poland
Jörg Rau
Chemical and Veterinary Analysis Agency Stuttgart, 70736 Fellbach, Germany
Christiane Baschien
Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, 38124 Braunschweig, Germany
Reinhard K. Straubinger
Chair of Bacteriology and Mycology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Institute for Infectious Diseases and Zoonosis, LMU Munich, 80539 Munich, Germany
Frank Ebel
Chair of Bacteriology and Mycology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Institute for Infectious Diseases and Zoonosis, LMU Munich, 80539 Munich, Germany
Sebastian Ulrich
Chair of Bacteriology and Mycology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Institute for Infectious Diseases and Zoonosis, LMU Munich, 80539 Munich, Germany
Stachybotrys chartarum is a toxigenic fungus that is frequently isolated from damp building materials or improperly stored forage. Macrocyclic trichothecenes and in particular satratoxins are the most potent mycotoxins known to be produced by this fungus. Exposure of humans or animals to these secondary metabolites can be associated with severe health problems. To assess the pathogenic potential of S. chartarum isolates, it is essential to cultivate them under conditions that reliably promote toxin production. Potato dextrose agar (PDA) was reported to be the optimal nutrition medium for satratoxin production. In this study, the growth of S. chartarum genotype S strains on PDA from two manufacturers led to divergent results, namely, well-grown and sporulating cultures with high satratoxin concentrations (20.8 ± 0.4 µg/cm2) versus cultures with sparse sporulation and low satratoxin production (0.3 ± 0.1 µg/cm2). This finding is important for any attempt to identify toxigenic S. chartarum isolates. Further experiments performed with the two media provided strong evidence for a link between satratoxin production and sporulation. A comparison of three-point and one-point cultures grown on the two types of PDA, furthermore, demonstrated an inter-colony communication that influences both sporulation and mycotoxin production of S. chartarum genotype S strains.
