The fungal spores elimination in drinking water by UV radiation

Abstract

UV radiation is effective on all microbial forms in water but lethal doses for every particular taxonomic group may be considerably different. Three species of Penicillium, Aspergillus and Cladosporium genera, 2 species of Alternaria and Fusarium and 1 species of Rhizopus and Paecilomyces genera were tested. Model waters were inoculated with spores of the mentioned monocultures. Three heterocultures: Aspergillus niger, Fusarium aquaductum and Paecilomyces varioti; Penicillium notatum, Aspergillus flavus, and Alternaria tenuis, Alternaria tenuis, Cladosporium fulvum and Rhizopus stolonifer were tested as well. The final spore concentration in water before me irradiation was approximately 104.l-1. The effects of various doses of UV radiation on the spores' germination and on the character of growth of mycelium were evaluated using cultivation methods. Our results show those bactericidal doses of UV radiation often effect stimulatory on the germination, growth rate and fructification of tested soil microfungi in heterocultures. These microfungi were able to highten their growth and germination after very high doses of UV radiation. These experiments indicate the doses of UV radiation necessary for elimination of heterogenous fungal contamination may be different from lethal doses for monocultures of the same species. Our results confirm the necessity to determine the disinfection doses of UV radiation for every water experimentally, not only by theoretical calculation.