Mycocenosis of Grape Berries Cultivated in the Central Slovak Wine Region

Abstract

Eleven samples of grapes from the Central Slovak wine-growing region were examined at the time of harvest in 2021 using the plating method and the plating method with surface disinfection. Plates were incubated aerobically at 25±1 °C in the dark for one week. Identification of fungi was based on morphological and microscopic characteristics. Of the 574 strains detected and identified in the exogenous mycobiota, the most common genus was Alternaria (90.9%), followed by Aspergillus (72.7%), Cladosporium, Penicillium, and Rhizopus (63.6%, each). The most abundant genera found by descending order were Alternaria (53.3%), Rhizopus (9.4%), Aspergillus (5.5%) and only in minor percentage by Penicillium (3%), among others. Of the 512 strains detected and identified in the endogenous mycobiota, the most common genus was Alternaria (100%), followed by Rhizopus (81.8%), Penicillium (72.7%), Aspergillus (63.6%), Cladosporium (45.5%), and Epicoccum (27.3%). The most abundant genera were Alternaria (61.1%), Cladosporium (13.1%), Aspergillus (11.7%), and Rhizopus (9%). The major fungal species isolated from the genera Aspergillus and Penicillium were Aspergillus section Nigri and Penicillium glabrum. Potentially toxigenic Aspergillus and Penicillium species were evaluated for toxinogenicity by thin-layer chromatography. Positive toxinogenity was found for all strains of Aspergillus clavatus tested and for almost all strains of Penicillium expansum and P. crustosum. Out of the two Aspergillus flavus isolates tested, none produced AFB1, AFG1, and CPA. Ochratoxigenic microfungi did not produce OTA.