Endophytic actinomycetes from Azadirachta indica A. Juss.: Characterization and anti-microbial activity

A total of 35 isolates of endophytic actinomycetes were obtained from 20 trees of Azadirachta indica A. Juss. These were then screened and evaluated for their biocontrol potential against an array of pathogenic fungi and bacteria. The dominant genus identified was Streptomyces sp. (23) and rest was related to other genera, like Micromonospora sp. (5), Microbiospora sp. (5) and Nocardia sp. (2). The distribution of endophytic actinomycetes was 42.9, 37.1 and 20 % in roots, stems and leaves respectively. Eight of the isolates were showing inhibitory activity against different plant pathogenic fungi and also fifteen isolates were displaying antagonism against human pathogenic bacteria. These results not only further our understanding of plant–microbe interactions but also indicate that there is an untapped resource of endophytic microorganisms that could be exploited in the biotechnological, medicinal and agricultural industries.