Antibacterial Activity of Methanolic Extracts of Amphibalanus amphitrite

Abstract

The emergence of antibiotic resistance has intensified the need for novel antimicrobial agents from marine sources. Barnacles (Balanus spp.), being sessile organisms, develop potent chemical defences against microbial colonization, making them promising candidates for marine bioprospecting. In this study, crude methanolic extracts of Amphibalanus amphitrite (BME), collected from the intertidal zone of Mumbai, were screened for zoochemical composition and antibacterial potential. Zoochemical analysis revealed the presence of alkaloids, phenolic compounds, terpenoids, saponins, carbohydrates, and proteins. Antibacterial activity, evaluated through the disc diffusion method, demonstrated significant inhibition against Streptococcus spp. (24 mm at 160 mg/mL) and Salmonella typhi (13 mm at 160 mg/mL), along with moderate effects against Corynebacterium diphtheriae and Staphylococcus epidermidis. These bioactivities are likely mediated by the synergistic actions of alkaloids, phenolics, terpenoids, and saponins, which disrupt microbial integrity and metabolism. The findings suggest that BME holds potential as a source of novel antimicrobial agents.