engleski

Investigation of Cytotoxic and Mutagenic Effects of the Plomin Bay Sediments

Disposal of the dredged material from the harbor to the sea bottom represents a route through which many contaminants could be transported towards open sea and enter the food chain. In this study, five sediment samples were taken from different depths and locations within the Plomin bay (Istria Peninsula, Northern Adriatic Sea, Croatia). Water sediment extracts were prepared, analyzed for chemicals and physical properties and subject to cytotoxic and mutagenic investigation. We used two strains of Salmonella typhimurium, TA98 (determination of frameshift mutations) and TA100 (detection of base pair substitutions) as a test system. The insensitivity of bacteria to heavy metals cytotoxicity and mutagenicity was avoided by changing the classical Ames assay with amodified preincubation. Cytotoxicity screening was made by spot test and by determination of frequency of the cell survival. For the mutagenic assay, sediment extracts and bacterial strains were preincubated for 24 hours at 370C (with and without metabolic activation) and incoporated on the minimal medium. After 72 hours the number of revertant colonies was counted. Concentrations of heavy metals measured in extracts represent exchangeable fraction and are 500-1000 times smaller thann the content of the same elements in the solid mud. None of the sediment sample extracts was cytotoxic or mutagenic for Salmonella typhimurium TA98 or TA100 in the presence/absence of metabolic activation.

Heavy metals; Marine sediments; genotoxicity; Ames assay

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