Investigating the Antimicrobial Activity of Bacteria associated with the Marine sponge Haliclona sp. collected from the Persian Gulf

To overcome the crisis of antibiotic resistance, the development of more effective antibiotics without side effects is an urgent need. Meanwhile, the bacteria associated with sea sponges have a good potential for discovering new antimicrobial compounds with a large variety of secondary metabolites. The present study was conducted with the aim of determining the antimicrobial activity of bacteria associated with the marine sponge Haliclona sp collected from the Persian Gulf.

In the present study, the antimicrobial effects of bacteria associated with the marine sponge Haliclona sp. collected from Lark and Kish islands in the Persian Gulf, were studied against Gram-positive bacterium Micrococcus luteus. After identifying and separating the samples, purification of sponge-related bacteria was done. Isolation and purification were done on culture media including Starch caseinnitrate agar, Marine zobell agar, Glycerol asparagine agar, Marinesponge agar. Then, in order to screen the biological activities of the purified bacteria, a nutrient broth culture medium was used. Finally, the antimicrobial activity of the isolated bacteria was measured using the well diffusion method against the gram-positive bacterium Micrococcus luteus.

The highest amount of bacteria associated with the sponge Haliclona sp. related to MSA, SCNA, MZA, and GAA culture media with the isolation of CFUg-1, were 5.88±0.05, 4.87±0.05, 4.20±0.03 and 2.75±0.23 related to sponges collected from Lark Island and 6.15±0.07, 5.08±0.05, 4.90±0.07 and 4.19±0.19 related to the sponges collected from the Kish island, respectively. As a result of purification, nearly 121 bacterial strains were purified, of which 12 purified bacterial strains had antibacterial activity.

The current findings demonstrated that the marine sponge Haliclona sp. has significant antibacterial effects; as a result, this marine sponge is a suitable candidate in future studies for the isolation of effective antibacterial compounds.