Actinomycetes are the most important sources of antibacterial compounds and they are the most important prokaryotic microorganisms in this regard. Marine Actinomycetes have been studied less than terrestrial actinomycetes. Although the number of new antibacterial compounds discovered from terrestrial actinomycetes has decreased, there is an increase in the re-isolation rate of known compounds and as a result, an increase in scientists’ attention towards aqua environments. To evaluate the antimicrobial compounds from Actinomycetes, water samples were obtained from the Gulf of Oman (Particularly, from Lipar area). Isolation of Actinomycetes was done by starch-casein agar, Starch Nitrate Agar and Glycerol Glycine Agar with different salt concentrations and heat treatment. Antibacterial production activity of the isolated Actinomycetes was assessed against pathogenic strains by cross streak method. In the total 177 isolated bacteria, 35 isolates belonged to Actinomycetes group, especially genus Streptomyces, based on morphological characteristics, pigment production and aerial mycelium. Among these, 33 isolates produce antibacterial compounds and their inhibition zone is varied between 1 to 25 mm in diameters. The highest recorded inhibition zone appears against Staphylococcus aureus and the lowest one, were against E.coli O157 H:7 and Pseudomonas aeruginosa. Preliminary results currently indicate that native Iranian Actinobacteria could be considered as new resources to screening the new antibacterial compounds. Molecular research is also being conducted.

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