Isolation and Characterization of Bacteria Associated with Brown Algae Sargassum spp. from Panjang Island and their Antibacterial Activities

Bacteria associated with brown algae represent a rich source of bioactive metabolites. Twenty-three marine bacterial strains associated with three species of brown algae Sargassum (S. polycystum, S. duplicatum and S. echinocarphum) were isolated using ZoBell 2216E from Panjang island, Jepara, North Java. The overlay and disk-diffusion methods were used to screen for antibacterial activity against pathogenic bacteria MRSA (Methicillin Resistant Staphylococcus aureus) and Staphylococcus epidermidis. Molecular characterization was investigated using PCR amplification 16S rRNA gene sequence. Homology analysis was used by using BLAST to identify the similarity, while phylogenetic tree was constructed by using neighbour joining tree. The result showed that the active strains of bacteria IB.6a.1 (Acc. No. LC002977) belonging to Bacillus subtilis with 95% sequence similarities. These findings suggest that the identified strains may contribute to the search for new sources of antibacterial substances.