RESUMEN
In the present study, 191 isolates of Streptomyces sp. were isolated from soil samples of the rhizospheres of Olea europae and Juniper procera trees from forests in Al-Baha region, Saudi Arabia. The isolates were grown on solid starch-casein medium and tested for their antifungal activities against some fungi. 88% of the isolates showed antifungal activity against seven fungi, Aspergillus ochraceus, A. nidulans, Circinella mucoroides, A. awamorli, A. terreus, Pencillium griseofulvum and A. niger. All isolates were able to completely inhibit the growth of A. achraceus and A. niger. Starch -casein was the best medium for producing the highest antifungal activity against most of tested fungi. The inhibition of growth of the tested fungi was increased by increasing the concentration of Streptomyces filtrate [grown on broth starch-casein medium]