OCCURRENCE OF PENICILLIUM SPECIES IN GRAPES FROM NITRA WINE REGION

Abstract

A study was carried out to investigate Penicillium species present on grapes grown in Slovakia. The survey involved Nitra wine region, located on southern Slovakia. In 2011 bunches of grapes (10) were collected from all 9 vineyards. A total of 50 berries (5 berries per bunch) from each sample were placed in Dichloran Rose Bengal Chloramphenicol agar medium. In this way was determined by using plate dilution method an exogenous mycobiota. The endogenous mycobiota was determined by the method of direct placing of superficially sterilized 50 wine grapes on the same medium. Cultivation lasted at 25 ± 1 °C in the dark from 5 to 7 days. During the survey, 170 isolates belonging to 6 Penicillium species were collected: P. citrinum, P. corylophilum, P. crustosum, P. decumbens, P. expansum and P. chrysogenum. The number of colonized samples was from 10 to 60 % and relative density from 0.6 to 28 %. P. chrysogenum was the most frequent, isolated in 40 % of the samples. The highest relative density belongs to P. crustosum (28 %) and P. chrysogenum (27 %). Toxinogenity of selected isolates was analysed by means of thin layer chromatography. Three potentially toxigenic species isolated from endogenous mycobiota were tested for their toxigenic ability. Out of 8 strains, 50 % produced at least one mycotoxin. Of all 15 potencially toxigenic strains from exogenous mycobiota all of them were positive on screening mycotoxins.