摘要
Objective:To isolate and screen actinomycetes for antimicrobial activity from mangroves and estuarine soil samples of Cochin.Methods:In the present study,sediment samples collected from mangroves and various stations of Cochin estuary were pretreated and actinomycetes were isolated on different selective media.The isolates were screened for antibiotic activity by following disc diffusion assay(Kirby-Bauer method)against human pathogens,fish pathogens and Gram-positive bacteria.The isolates were identified based on their morphology.Results:Only 2 actinomycete isolates(ER7 and ER10)of the 50 isolates screened had antimicrobial activities against one or more pathogens tested.ER7 isolate showed higher antimicrobial activity as compared to that of ER10 isolate.The maximum inhibition zone of crude extract from ER7 was 16.7 mm.The methanol extract of ER7 showed antimicrobial activity against all the pathogens tested with a maximum zone of 21.0 mm.The isolates with antimicrobial activity were found to belong to the genus Streptomyces.Conclusions:There is no significant report on bioactive actinomycetes from the present study areas.Potent antibiotics from the selected isolates could contribute to fight against several human and fish diseases.Further purification,structural elucidation and characterization are recommended to know the quality,novelty and commercial value of these antibiotics.Hence,the mangroves and estuary of Kochi show great promise for the discovery of bioactive actinomycetes.
