Exploitation of Antibacterial Compound Producing Marine Actinobacteria against Fish Pathogens Isolated from Less Explored Environments

Totally, 82 actinobacteria were isolated from the marine sediment samples of Bay of Bengal, east coast of Tamilnadu, India. Of 82 isolates, 21 (26%) actinobacteria were possessed antibacterial activity against fish pathogenic bacteria namely Vibrio alginolyticus, V. parahaemolyticus, V. cholera, Aeromonas sp. and Pseudomonas sp. Among 21 antagonistic isolates, the isolate ECR77 and ECR 64 showed good inhibitory activity against test pathogens. The crude antibacterial compounds from the potential antagonistic isolates were extracted using different solvents after submerged fermentation. Of the various solvent extracts tested, ethyl acetate extract was showed good antibacterial activity against V. alginolyticus, V. cholera and Pseudomonas sp. The potential antibacterial compound producing isolates were characterized by using standard methods of ISP (International Streptomyces Project) and tentatively identified as Streptomyces sp.