Guttation droplets of Penicillium nordicum and Penicillium verrucosum contain high concentrations of the mycotoxins ochratoxin A and B
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Eight of eleven ochratoxigenic isolates of Penicillium nordicum and Penicillium verrucosum produced guttation droplets when grown on Czapek yeast extract (CYA) agar for 10–14 days at 25°C. Parallel cultivation of one strain each of P. nordicum and P. verrucosum on malt extract agar demonstrated that higher volumes of exudate are produced on this agar. However, HPLC analyses revealed higher concentrations of ochratoxin A (OTA) and B (OTB) in droplets originating from cultures on CYA. For quantitative determination of the mycotoxin contents, triplicates of three isolates each of P. nordicum and P. verrucosum were grown as single spot cultures on CYA for up to 14 days at 25°C. Guttation droplets were carefully collected between day 11 and 14 with a microliter syringe from each culture. Extracts from exudates and corresponding mycelia as well as fungal free agar were analyzed by HPLC for the occurrence of ochratoxin A (OTA) and B (OTB). Mean concentrations ranging between 92.7–8667.0 ng OTA and 159.7–2943.3 ng OTB per ml were detected in the guttation fluids. Considerably lower toxin levels were found in corresponding samples of the underlying mycelia (9.0–819.3 ng OTA and 4.5–409.7 ng OTB/g) and fungal free agar (15.3–417.0 ng OTA and 12.7–151.3 ng OTB/g). This is the first report which shows that high amounts of mycotoxins could be excreted from toxigenic Penicillium isolates into guttation droplets.
KeywordsExudate Fungal droplets Guttation Mycotoxin Ochratoxin A Ochratoxin B Penicillium spp. Secondary metabolites
Czapek yeast extract agar
High performance liquid chromatography
Malt extract agar
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We are grateful to Ms. Petra Peetz and Ms. Georgine Krappmann for the excellent technical assistance and to Dr. Thomas Ostenfeld-Larsen and colleagues from the BioCentrum, Denmark for supplying the IBT strains.
- 1.Ivanoff SS. Guttation injuries of plants. Bot Rev 1963;29:202–8Google Scholar
- 2.Raper KB, Thom Ch. A Manual of the Penicillia. New York, London:Hafner Publishing Company; 1968Google Scholar
- 3.Thom Ch. The Penicillia. Baltimore:The Williams &Williams Company; 1930Google Scholar
- 4.Samson RA, Hoekstra ES, Frisvad JC, Filtenborg O. Introduction to food- and airborne fungi. 6th ed. Utrecht:Centraalbureau voor Schimmecultures; 2000Google Scholar
- 6.McPhee WJ, Colotelo N. Fungal exudates I. Characteristics of hyphla exudates in Fusarium culmorum. Can J Bot 1976;55 Suppl 358:65Google Scholar
- 8.Pitt JI, Hocking AD. Fungi and Food Spoilage. 2 ed. London:Blackie Academic Professional; 1997Google Scholar
- 13.McPhee WJ, Colotelo N. Fungal exudates. I. Characteristics of hyphal exudates in Fusarium culmorum. Can J Bot 1977;55 Suppl 358:65Google Scholar
- 17.Frisvad JC, Smedsgaard J, Larsen TO, Samson RA. Mycotoxins, drugs and other extrolites produced by species in Penicillium subgenus Penicillium. Stud Mycol 2005;49:201–41Google Scholar
- 19.Pittet A. Natural occurrence of mycotoxins in foods and feeds-an updated review. Rev Med Vet 1998;149:479–92Google Scholar
- 23.Krogh P. Ochratoxins: Occurrence, biological effects and causal role in diseases. Toxicon, Supplement 1980;2:673–80Google Scholar
- 26.Cayrol JC. Nematicidal toxins of fungi. Rev Horticole 1989;293:53–7Google Scholar
- 27.Gareis M, Göbel E. Aufnahme und Verbreitung von Ochratoxin A durch Milben (Tyrophagus casei). In: Wolff J, Betsche T, editors. Proceedings 20.Mykotoxin-Workshop. 1998. 29–31; Detmold; Institut für Biochemie von Getreide und Kartoffeln,Bundesanstalt für Getreide-,Kartoffel- und Fettforschung, Detmold; 3-921875-00-9Google Scholar