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(71-07) Effects of Zinc - and Copper pyrithione on natural occurring microbial sediment communities. Groth Petersen, Dorthe*,1, Dahllöf, Ingela1, 1 NERI, Fredriksborgvej 399, Roskilde, Denmark ABSTRACT- Zinc pyrithione (ZPT) and Copper pyrithione (CPT) are biocides used in marine antifouling paints. Their modes of action include disruption of the proton gradient, thereby disturbing the intracellular ATP levels, as well as transportation of metals across cell membranes. The aim of this study was to examine the effects of ZPT and CPT on naturally occurring microbial sediment communities using end-points such as nutrient turnover (fluxes), protein synthesis (growth) and bacterial diversity. Fluxes of nutrients (nitrat, ammonium, phosphate and silicate) integrate the total microbial community function and describe the degradation of organic matter in the sediment, which is an essential part of the circulation of nutrients. Effects of ZPT and CPT on protein synthesis were measured by incorporation of 14C-leucine into bacterial cells. Additionally, molecular methods (Polymerase Chain Reaction, PCR and Denaturing Gradient Gel Electroforesis, DGGE) were used to describe possible changes in bacterial diversity. The connection between functional measurements (fluxes and 14C-leucine incorporation) and molecular community analysis in ecotoxicological studies is relatively new, but it has interesting perspectives in future analysis on effects of various toxic compounds. Preliminary results show that ZPT and CPT affect nutrient fluxes, especially nitrate fluxes, starting at nominal concentrations of 0.1 nmol/g dry sediment. Furthermore, the protein synthesis was affected by addition of ZPT and CPT, but at higher concentrations. Analysis of effects on bacterial diversity will also be presented. Key words: ecotoxicology, bacteria, diversity, biocides |
