Exploring Marine Invertebrate-Associated Bacteria for Novel Antibiotics Discovery

Marine bacteria associated with marine invertebrates are interesting source to explore compounds with potential bioactivities. In this study we screened bacteria associated with various samples (n=16) from Pulau Pari, Kepulauan Seribu, Jakarta for their antibacterial activities. The aim of this study is to obtain potential bacterial strains that can produce novel antibiotics. Isolation of bacteria from the 14 marine invertebrates and 2 of other marine samples was performed in four media: Marine Agar, ISP2, YMA, and MS. A total of 97 bacterial strains were selected to test their antibacterial activity against Gram-positive (Mycobacterium smegmatis NCTC 8159, Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6051) and Gram-negative bacteria (Eschericia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853). The result showed a total of 19 bacterial strains were active. Furthermore, one strain (MS.P.013.2) exhibited potent antibacterial activity against M. smegmatis. Partial identification of the strain using 16S rRNA sequencing revealed 99.58 sequence similarity to Micrococcus luteus NCTC 2665^T. Chemical analysis of the MS.P.013.2 methanol extracts using GC-MS showed the majority of volatile compounds were 9,12-Octadecadienoic acid, methyl ester; 9,12-Octadecadienoic acid (Z,Z); Octadecanoic acid; 2-(Dimethylamino)ethyl vaccenoate; and Cyclopropane,1,1-dichloro-2,2,3,3-tetramethyl-. These compounds were previously reported to have putative antibacterial activity, emphasize the prospect of targeting this bacterial strain for further exploration, especially to isolate and to characterize novel antibiotics. © © 2025 by Indonesian Journal of Pharmacy (IJP).