RESUMO
The search for novel antibiotics is of immense importance in research areas around the world for agricultural,pharmaceutical, and industrial applications. The Streptomyces species are widely used as an importantbiological tool for the production of a wide range of novel secondary metabolites. In the present study, isolatedstrain RSA-14 from rhizosphere soil of Alternanthera sessilis was subjected to morphological, physiological,biochemical and 16S rRNA gene sequence analysis. The isolated RSA-14 was analyzed for antimicrobialactivities by cross streak method and exhibited a broad spectrum of antimicrobial activity against test pathogens.The isolate was tested for the ability to grow in the presence of antibiotics, such as penicillin, streptomycin,chloramphenicol, gentamycin, and tetracycline and resistant to only two antibiotics, and sensitive to others. The16S ribosomal RNA gene sequencing and analysis of the phylogenetic tree showed 100% sequence similaritywith Streptomyces cinereoruber strain P.B.373.