Antimicrobial activity of some bacteria isolated from marine sponge in Neom region, Saudi Arabia

Antimicrobial resistance reduces the possibility of avoiding and curing infectious diseases triggered by bacteria, viruses, parasites, and fungi. Therefore, searching for new antimicrobials from prolific producers of novel natural products, including marine sponges, is necessary to address this resistance. Marine sponges are known to host diverse microbial communities, many of which are prolific producers of bioactive secondary metabolites. Several biological activities are exhibited by bioactive metabolites extracted from marine sponges. Mounting research demonstrates that these secondary metabolites arise from microorganisms rather than sponges. This paper aims to assess the in vitro antimicrobial activity of bacteria associated with the marine sponge sample collected from the NEOM region of Saudi Arabia. Based on the morphology of the bacterial colonies, 13 marine bacterial isolates were obtained from the Negombata magnifica sponge sample using a culture-dependent method. Results indicate that screening of isolated strains showed that only two (15.4%) bacteria possess antimicrobial activity against some human pathogens, as determined by an agar plug diffusion method with fungi and an agar well-diffusion method with bacteria. Potential marine bacterial strains MB3 and MB8 were selected to identify bioactive products using GC-MS analyses. Bioactive compounds include Phenol, 2,4-bis(1,1-dimethylethyl)-, Tryptophol, and Pyrrolo[1,2-α]pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl)- (PPDHMP) were detected from the culture extract of strain MB3 and PPDHMP from MB8. Overall, this study highlights the potential of marine bacteria, symbiotically associated with the NEOM sponge sample, to produce antimicrobial compounds effective against human pathogenic microorganisms, like Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis, Klebsiella pneumoniae, and the fungus Candida albicans.