Plant Growth Promoting Properties of Endophytes from Azadirachta Indica

Present study was undertaken to evaluate plant growth-promoting and enzymatic traits of six endophytic bacterial isolates (Bacillus subtilis, Bacillus subtilis, Paenibacillus amylolyticus, Pseudomonas aeruginosa, Bacillus zhangzhouensis and Bacillus cereus) from Azadirachta indica. All isolates showed ability to synthesize indole-3-acetic acid (IAA), solubilize phosphate to a limited extent, fix atmospheric nitrogen, produce ammonia, and generate low levels of hydrogen cyanide. Zinc solubilisation and ACC deaminase activity was also observed in three isolates. Siderophore production was confirmed in two isolates while all isolates exhibited biofilm formation, indicating their adaptability and colonization capacity. Four isolates showed amylase activity, while cellulose, esterase and lipase activities were detected in all the six isolates, four isolates also showed protease. The findings established multifunctional capabilities of the isolates, indicating their potential applications in sustainable agriculture through nutrient mobilization, stress tolerance, and plant growth promotion.