MICROFUNGI AND MYCOTOXINS OF GRAPES FROM TOKAJ WINE REGION

Abstract

The aim of this study was to investigate a surface mycobiota of grapes and detection a potentially pathogenic isolates to produce selected mycotoxins. Three samples of wine grapes Furmint, Lipovina and Yellow muscat were collected in the Tokaj wine region in ViniÄky during the November harvest in 2012. Seven/eight berries from each sample were placed on a Dichloran Rose Bengal Chloramphenicol agar in a total of 50 and incubated at 25 °C for 5 - 7 days. After incubation from the samples were isolated following filamentous fungi: Alternaria, Aspergillus, Botrytis, Cladosporium, Mucor, Penicillium, Phoma, Rhizopus, Trichoderma and Mycelium sterillium. The most frequent were genera Aspergillus, Botrytis and Penicillium with 100 % frequention. The largest number of isolates belonged to Penicillium (368 isolates) and Botrytis (334 isolates). For that reason the relative density of both genera were the highest 47 % and 43 %, respectively. The selected isolates - Aspergillus section Nigri, Penicillium crustosum, Penicillium expansum and Penicillium chrysogenum were tested for patulin, citrinin, penitrem A, roquefortin C and ochratoxin A producing ability. A higher percentage of Penicillium crustosum isolates (79 %) were positive for penitrem A and all were positive for roquefortin C. A higher percentage of Penicillium expansum (83 %) were positive for patulin, 72 % for citrinin and they were all positive for roquefortin C. All isolates of Penicillium chrysogenum produced roquefortin C. As would be expected, ochratoxin A was not detected from Aspergillus section Nigri.