The development of biofilm bacteria on panels coated by different antifouling paints in the marinas

The goal of the research was to isolate and identify biofilm bacteria on static panels, and to determine the minimum inhibitory concentrations (MICs) of the antifoul-ing agents preventing the growth of biofilm bacteria. The effectiveness of four types of antifouling paints containing additives based on zinc oxide, copper oxide, tributyltin, fluorine and triazine diamine as well as one type of rustproof paint against biofilm formation on static panels was determined. Bacterial strains were isolated from biofilms formed on test panels embedded in the two marinas located at Izmir region. Bacterial growth was found on all test panels and counts of them on the surfaces of the panels rapidly increased in the period of 7-15 days. Twenty-six strains were cultured, and a total of 13 unique strains were identified. Phylogenetic analysis using 16S rDNA sequences indicated that all of the strains belonged to the ?-Proteo-bacteria and Firmicutes subclasses {Pseudoalteromonas agarovorans, P. haloplanktis, P. marina (3 strains), P. elyakovii (2 strains), P. porphyrae (2 strains), Alteromonas genoviensis, A. alvinella, Vibrio lentus and Exiguobacte-rium homiense). The paint, which contains triazine diamine and copper oxide, showed strong antibacterial activity against each individual strain. None of the isolates grew in all concentrations (1/2 to 1/1024) of this paint. Physico-chemical parameters of seawater and viable bacteria counts displayed relations during the study period. However, it was not found any strong correlation between viable bacteria density and nutrient concentrations.