Identification of genotoxic potential of surface water and sediment samples of the Sava river by Ames biotest

Abstract

Primarni cilj NATO SfP projekta Assessment of Hazardous chemical contaminatin in the Sava River basin bio je razviti i primijeniti suvremeni, tzv. EDA (eng. effects-directed analysis) pristup u monitoringu i procjeni rizika od onečišćenja u području bazena rijeke Save. EDA pristup temelji se na kombinaciju bioloških analiza u obliku bioloških testova toksičnosti (biotestova), i analitičko kemijskih kromatografskih tehnika, kako bi se ciljano došlo do identifikacije kemikalija odgovorih za toksični učinak. U okviru serije biotestova korištenih u ovom projektu provodio se i Ames test, kao danas najprihvaćeniji test kojim se određuje ima li neka tvar genotoksični učinak. Test smo provodili uz pomoć posebno konstruiranih sojeva bakterije vrste Salmonella typhimurium, a za detekciju premutagena (tvari koje u procesu bioaktivacije stvaraju mutagene metabolite), prilikom izvođenja testa u pokusnu smjesu smo kao aktivacijski sustav dodavali postmitohondrijsku frakciju jetre štakora. Rezultati Ames testa jasno su pokazali da analizirani uzorci sedimenata ne posjeduju mutageni potencijal, dok pojedini uzorci površinskih i otpadnih voda pokazuju granične vrijednosti s obzirom na međunarodno prihvaćene kriterije za mutagenost.The main goal of the NATO SfP project entitled Assessment of Hazardous chemical contaminatin in the Sava River basin was to develop and implement a modern, EDA (Effects Directed Analysis) approach customed for monitoring and risk assessment of hazardous chemical contamination in the Sava River basin. EDA approach uses the combination of biological assays (biotests) and analytical chemical detection and separation technique to direct the identification of contaminants causing toxic effects. Within a series of biotests used in the project, the Ames bacterial test was applied as the most widely used assay for assessment of mutagenicity of tested compounds or complex environmental samples. Test was performed using genetically modified strains of Salmonella typhimurium, and for detection of premutagens (substances that express mutagenicity upon enzymatic bioactivation) the postmitochondrial fraction of rat liver was used as activation system. Our results clearly showed that the analyzed samples of sediments do not possess the mutagenic potential, while some surface and waste water samples showed threshold values in respect to internationally accepted criteria for mutagenicity