Antibacterial activity of resin based coatings containing marine microbial extracts

Bioactive agents produced by marine surface‐associated bacteria have been incorporated into experimental antifouling coatings. It was found that coating formulation can affect the action spectra of bacterial extracts involved. Little work has been done on the effect of permeability on the leaching of bioactive compounds from antifouling coatings. The formulations with 1.5% and 1.0% alginate produced significantly larger zones (p < 0.05) than with 0.5% alginate. Test formulations continued to leach active compounds after continuous immersion in seawater for 120 h. The bacterial strains used to produce the active compounds were identified by biochemical tests and/or the analysis of the DNA from a 500 bp section of the gene coding for the 16S rRNA subunit. Strains used were tentatively identified as Planococcus citreus, seven Bacillus strains (including three Bacillus pumilus and three Bacillus lautus strains), Cytophaga fucicola, Cytophaga uliginosa and a Pseudoalteromonas spp.