Antibacterial activity of marine bacteria isolated from sponge Xestospongia testudinaria from Sorong, Papua

Objective: To explore secondary metabolite of bacteria-associated Xestospongia testudinaria from Tanjung Kasuari, Sorong, Papua. Methods: The antimicrobial activities of extracts against two Gram-positive bacteria (Staphylococcus aureus) and three Gram-negative bacteria (Pseudomonas aeruginosa, Eschericia coli and Salmonella typhi) were determined by disk diffusion dilution method. Results: The test showed that of 15 isolates of symbiont bacteria, 6 isolates were successfully isolated and coded, namely, Xp 4.1, Xp 4.2, Xp 4.3, Xp 4.4, Xp 4.5 and Xp 4.6. Of the six bacterial isolates, isolated Xp 4.2 was found to have more powerful antibacterial activity than any other isolates of symbiont bacteria. Antibacterial activity assay for the n-hexane soluble fractions, ethyl-acetate soluble fractions, and n-buthanol soluble fractions revealed more powerful anti-bacterial activity than any other soluble fractions. Phytochemical screening showed alkaloid and steroid/triterpenoid, while identification for isolate of Xp 4.2 bacterial showed bacteria. Conclusions: Metabolites of bacterial associated with marine sponge Xestospongia testudinaria promise to be developed into antibacterial agents.