Distribution pattern analysis of epiphytic bacteria on ethnomedicinal plant surfaces: A micrographical and molecular approach

The epiphytic bacterial community prevalent on ethnomedicinal plant surfaces were studied for their diversity, niche localization and colonization using the micrographical and molecular approaches. Scanning electron microscopy (SEM) revealed the presence of large aggregates of bacterial communities. The bacterial localization was observed in the grooves along the veins, stomata and near the trichomes of leaves and along the root hairs. A total of 20 cultivable epiphytes were characterized which were analyzed for richness, evenness and diversity indices. Species belonging to the genera Bacillus and Pseudomonas were the most abundant. Bacillus thuringiensis was the most prevalent epiphyte with the ability to form biofilm, as a mode of adaptation to environmental stresses. Biofilm formation explains the potential importance of cooperative interactions of epiphytes among both homogeneous and heterogeneous populations observed under SEM and influencing the development of microbial communities. The study has revealed a definite pattern in the diversity of culturable epiphytic bacteria, host-dependent colonization, microhabitat localization and biofilm formation which play a significant role in plant–microbe interaction.