Streptomycetes consider as an important source of bioactive natural compounds. They are play an
important role with tremendous applications in biological and biotechnological fields. Marine streptomycetes are particularly important microorganisms. Seven streptomycetes isolates were obtained from a marine source and tested for their ability to produce bioactive secondary metabolites. Their Antibacterial activity against were tested against a variety of potato pathogenic bacteria, including those that cause potato brown rot and soft rot illnesses. Using semi-selective media, Ralstonia solanacearum (a soil-borne pathogen) that cause potato brown rot was previously isolated from illnesses of potatoes with typical brown rot symptoms (SMSA). While the bacterium that causes potato soft rot (Pectobacterium atrosepticum) was isolated from infected potatoes and showed soft rot symptoms on logan's medium.