Antimicrobial potential of Actinomycetes species isolated from marine environment

Objective:To evaluate the antimicrobial activity of Actinomycetes species isolated from marine environment.Methods:Twenty one strains of Actinomyceteswere isolated from samples of Royapuram, Muttukadu, Mahabalipuram sea shores and Adyar estuary. Preliminary screening was done using cross-streak method against two gram-positive and eight gram-negative bacteria.The most potent strains C11 and C12 were selected from which antibacterial substances were extracted. The antibacterial activities of the extracts were performed using Kirby-Bauer disc diffusion method. Molecular identification of those isolates was done.Results:All those twenty one isolates were active against at least one of the test organisms. Morphological characters were recorded. C11 showed activity againstStaphylococcusspecies(13.0暲0.5 mm),Vibrio harveyi(11.0暲0.2 mm),Pseudomonas species(12.0暲0.3 mm). C12 showed activity against Staphylococcus species(16.0暲0.4 mm),Bacillus subtilis(11.0暲0.2 mm),Vibrio harveyi(9.0暲0.1 mm),Pseudomonas species(10.0暲0.2 mm). 16S rRNA pattern strongly suggested that C11 and C12 strains were Streptomyces species.Conclusions:The results of the present investigation reveal that the marineActinomycetesfrom coastal environment are the potent source of novel antibiotics.Isolation, characterization and study of Actinom ycetescan be useful in discovery of novel species of Actinomy cetes.