Investigation on the bioactivity of culturable endophytic and epiphytic bacteria associated with ethnomedicinal plants

Abstract

Introduction: The growing need for the bioactive compounds of ethnomedicinal plants for the treatment of diseases has resulted in exploitation of medicinal plants. The present investigation aimed to study the diversity of endophytic and epiphytic bacteria associated with ethnomedicinal plants and to explore their potential as source of bioactive compounds. Methodology: Characterization of culturable endophytic and epiphytic bacteria associated with 11 ethnomedicinal plants and their potential as natural antioxidants was assessed through free radical scavenging activity, total phenolics, total flavonoids, metal ion chelation, and antagonistic activity. Genetic screening to assess the potential of endophytes and epiphytes to synthesize bioactive compounds was achieved by screening for the presence of the non-ribosomal peptide synthetase (NRPS) gene. Result: The frequently isolated endophytic bacterium recovered was Bacillus sp. Antioxidative property of the bacterial extracts revealed endophytes with potent antioxidant activity and better antagonistic activity as compared to epiphytes. Genetic screening revealed the presence of the NRPS gene in seven plant-associated bacteria, indicating the production of natural products. Conclusions: The study indicated the extracts of bacterial endophytes associated with ethnomedicinal plants as good sources of natural products with potential application in oxidative stress. The isolates could be used as new bioactive agents.