ABSTRACTObjectives: The present investigation is undertaken with an aim to check the antimicrobial potential of marine Actinobacteria isolated from marinesediment samples collected from Pulicat Lake, Tamil Nadu.Methods: In this study, various physical and chemical pretreatment methods were used for selective isolation of Actinobacteria including air drying,incubation of soil samples with calcium carbonate, incorporation of antibacterial, antifungal antibiotics in the media and plating on Actinobacteriaspecificmedia.Acombinationof suchmethodsfacilitatedisolationof slowgrowingActinobacteriawith a simultaneous reductionof otherfree-livingbacterialand fungalcontaminants. The primary and secondary screeningwasdone toascertain the antimicrobialpotentialof these isolates.Results: The results obtained from primary screening was about 110 isolates, were tested against Pseudomonas aeruginosa, Staphylococcus aureus,Candida albicans, and Aspergillus niger, out of these, 31 isolates showed remarkable antimicrobial activity. Based on the results of primary screening,31 isolates were subjected to secondary screening from which two isolates with a strong and broad spectrum of antimicrobial activity were selectedfor further studies.Conclusion: The present study is useful as the isolation of most of the antimicrobial compounds from different Actinobacteria species showed partialresemblance to earlier reported antibiotic chemical structures. Further, chemical characterization of the isolated compound from producer isolatesmay yield more effective analogs or hybrid bioactive molecules.Keywords: Actinobacteria, Antimicrobial activity, Pulicat lake
