Screening Of Antibiotic Producing Actinomycetes From The Sediments Of Undisturbed Forest Areas And Its Hyper Activity After Mutation

Wide and uncontrolled usage of antibiotics has made the pathogens to become resistant to currently used antibiotics. There is an urgent need for development of a new drug or a highly active molecule for controlling antibiotic resistant strains. In this study 32 strains of Actinomycetes were isolated and subjected to primary screening by giant colony method against Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Aeromonas hydrophilia. The secondary screening was carried out by fermentation process. Antibacterial activity was evaluated by well plate method. The extract of isolates was subjected to well plate method against pathogenic bacteria. B. subtilis and E. coli were highly inhibited by AK1 isolate. Other isolates showed limited inhibition of bacteria. The AK1 isolate was mutated by UV irradiation. The mutants differed from the wild parent in reduced growth rates, changes in the shape and size of the colony, sporulation level, antibiotic activity and variation in the color of the mycelium. The zone of inhibition was higher with Actinomycetes AK1 inoculated plates. The secondary metabolite production was enhanced by UV mutagenesis when compared to wild type. Actinomycetes may produce different molecule that can inhibit different types of pathogens, however efforts like strain development can be done to produce new bioactive components against multidrug resistant bacteria.