Distribution of Endophtyic Actinomycetes of Three Medicinal Plants and Evaluation of Their Antibacterial Potencies

Abstract

This study was under taken to find actinomycetes diversity within some medicinal plants and focused on their antibacterial potentials. Presently endophytic microorganisms are less explored microbial habitat and most interesting source of novel antimicrobial agent. Three medicinal plants; Vinca rosea, Cinnamomum sp. and Solanum sisymbrifolium were selected for actinomycetes isolation. Surface sterilized stems were subjected to various media for endophyte isolation. Total 14 actinomycetes were isolated in this study in which 57 % belonged to genera Streptomyces, 7 % each of Nocardia, Streptoverticillium and Micromonospora, 15 % Streptosporangium and 1 isolate remained unidentified. Isolates were identified by microscopic (SEM), morphological, physiological and molecular characterization. All isolates were evaluated for antibacterial property against 5 Gram negative and 2 Gram positive human pathogenic bacteria. Study showed that endophytic isolate Streptomyces thermovilaceus NT1, S. rochei CH1 and isolate Streptomyces sp. BT5 were active against most of the test pathogens where no isolate except NT1 was active against P. aeruginosa. Based on above results it can be concluded that endophytic actinomycetes are an advanced source of potential antimicrobial agent for future medicine.