Abstract
The extracellular polymeric substance (EPS) produced by an epibiotic bacterium isolated from the surface of the polychaete worm Platynereis dumerilii was assessed for its inhibitory activity against two biofilm forming bacterial strains. The polychaete Platynereis dumerilii was collected from the coastal waters and the bacterial communities associated with the surface was isolated using traditional culture method. The EPS of the bacterial strain strongly inhibited the growth of target bacteria in disc diffusion assay. The adhesion assay showed that the number of cells adhered on the control slides were higher than that the number of cells found on the slides coated with EPS. The bacterial strain was identified as Exiguobacterium sp. by 16S rRNA gene sequencing. Thin layer chromatography analysis showed the presence of a single active compound in the EPS with the Rf value of 1.47 cm. The HPLC spectrum of the EPS showed two prominent peaks. Results indicate that epibiotic bacterial communities associated with polychaetes would serves as a potential source for the biofilm inhibitory compounds.