The objective of this research was to screen, select and isolate actinomycetes from 10 salty soil samples. The ability of the isolated strains to produce antimicrobials metabolites was evaluated against pathogenic strains: Escherichia coli; Staphylococcus aerus and Candida albicans by using disc diffusion agar plate technique. Optimization of the production of bioactive metabolites from the most potent isolate was also demonstrated. The crude extract of the metabolites produced by the 41 actinomycetes isolates proved to have antimicrobial activity against one or all the tested pathogen. Among all the isolated strains, NRC-S4 isolate exhibited highest activity against all the tested pathogen and was selected for further studies. Out of 13 tested carbon sources, starch was the most suitable one. From 11 organic and inorganic tested nitrogen sources, ammonium nitrate was found to be the best source. The maximum antimicrobial bioactive metabolites produced by the optimized culture medium containing g/L sea water: soluble starch, 35; NH4NO3, 3.5; K2HPO4, 1; MgSO4.7H2O, 0.5; CaCO3, 3; with inoculums volume of 5% at pH7, 30°C and 170 rpm for 12 days.
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