Isolation and Morphological Characterization of Barnacle-Derived Actinomycetes from Southern Regions with Potent Anti-MRSA Activity

Marine environments represent an underexplored reservoir of bioactive microorganisms with significant pharmaceutical potential. The present study aimed to isolate and characterize actinomycetes associated with marine barnacles collected from Chinnavilai Beach, Kannyakumari District, Tamil Nadu, India, and evaluate their antimicrobial activity against selected pathogens. A total of 17 actinomycetes strain were isolated using selective actinomycetes isolation medium, of which four morphologically distinct isolates (BAR1-BAR4) were selected for detailed investigation. The isolates were characterized based on macroscopic and micromorphological features, including aerial and substrate mycelium, pigmentation, and spore chain morphology. Antimicrobial screening using the agar plug. Revealed that the isolates exhibited varying degrees of inhibitory activity against clinical important pathogens, with isolate BAR2showing pronounced activity, particularly against Methicillin-resistant staphylococcus aureus (MRSA), along with notable inhibition of Actinetobacter baumannii and klesiella pneumonia. The findings demonstrate that marine barnacle associated actinomycetes are a promising source of potent antimicrobial agents and highlight their potential role in the discovery of novel secondary metabolites to combat multi drug resistant bacterial infections.