Occurrence of microscopic fungi in the Slovak section of the Danube River

During 1994-1998 altogether 200 samples of Danube water were investigated a nd microscopic fungi were identified in all samples. Abundance and specific diversity of microscopic fungi can oscillate in surface water during seaso ns. This seasonal variability depends on availability and amount of substra te. In the Danube river fungi abundance ranged within 1 to 45 CFU mL(-1) wi th maximum in summer sampling time. Five genera of the subdivisio Zygomycot ina and 32 genera of the subdivisio Deuteromycotina were identified by rout ine isolation and cultivation methods with prolonged cultivation time to 7- 30 days at room temperature and day light. The most frequently isolated spe cies belong to the genera Penicillium, Acremonium, Alternaria, Cladosporium , Fusarium, Paecilomyces, Trichoderma and Mucor. In some cases the identifi ed species belong to the genera Mortierella, Rhizopus, Candida, Aspergillus , Beauveria, Geotrichum, Gliocladium, Phialophora, Stachybotrys, Stemphylli um, Trichophyton, Verticillium and other. Rarely the species as Absidia, Zy gorhynchus, Arthrinium were isolated. Species diversity dynamics in longitu dinal profiles in the Danube indicated more abundant diversity of the subdi visio Zygomycotina in profile Bratislava. Three species - Beauvaria bassian a (BALS.) VUILL., Verticillium malthousei WARE and Verticillium lecani (ZIM M.) VIEGAS were isolated in the Danube river water as new species identifie d in the Slovak Republic. The data reported here refer to importance of microscopic fungi monitoring in surface water. Knowledge about fungi occurrence in atypical environment contribute to extend information about the species diversity.