Vol. 9, Issue 1, Part D (2025)

The increasing demand for sustainable agricultural practices has prompted the exploration of plant growth-promoting bacteria (PGPB) as eco-friendly alternatives to chemical fertilizers. This study aimed to isolate, characterize, and screen Azotobacter, Bacillus, and Pseudomonas species for their plant growth-promoting activities, including nitrogen fixation, phosphate solubilization, IAA production, and antifungal activity. Soil samples were collected from the rhizosphere of wheat, maize, and rice crops at SDMVMS College of Agricultural Biotechnology, Aurangabad. The isolates were characterized morphologically and biochemically, confirming their identity as Azotobacter, Bacillus, and Pseudomonas. Azotobacter demonstrated significant nitrogen fixation, as evidenced by ethylene production and ammonia detection. Bacillus and Pseudomonas exhibited phosphate solubilization, with Pseudomonas showing slightly higher solubilization indices. All isolates produced IAA, with Azotobacter showing the highest production. Antifungal activity was observed in all isolates, with Bacillus exhibiting the strongest inhibition against Fusarium oxysporum and Rhizoctonia solani. These findings highlight the potential of Azotobacter, Bacillus, and Pseudomonas species in enhancing crop growth and soil health, offering a sustainable approach to improving agricultural productivity.