Diversity and antibacterial potential of endophytic actinomycetes isolated from medicinal plants of Rajkot, India

Abstract

Endophytic actinomycetes from medicinal plants of Rajkot district were isolated and screened for their antibacterial activity against several pathogenic bacteria. A total of 36 separate endophytic isolates were obtained from 7 medicinal plants and 22.22% of these showed antagonistic activity against pathogens. Most of the endophytic actinomycetes were recovered from roots (55.56% of all isolates) followed by leaves (44.44%). No epiphytes were grown during isolation which shows the effectiveness of surface sterilization technique. Six (16.67%) endophytic actinomycetes showed broad spectrum antibacterial activity inhibited both Gram-positive and Gram-negative bacteria including multi drug resistant S. aureus, where as two (5.56%) actinomycetes was effective against only gram negative bacteria. One of the potential endophytic actinomycetes EA7 was chosen for further study on the basis of zone of inhibition and broad spectrum activity. Antibacterial compound from EA7 was efficiently separated by analytical TLC using Chloroform-Methanol, 24:1 solvent system and further UV absorption spectrum maxima recorded at 223 nm. These results indicate that endophytic actinomycetes from medicinal plants have potential antibacterial activity that could be further exploited for industrial applications.