Journal of Advances in Biology & Biotechnology

This study investigated the potential of indigenous phosphate-solubilizing bacteria (PSB) to address phosphorus limitation in the semi-arid tropical soils of Sangareddy district of Telangana state. By isolating microbial strains from diverse rhizospheric environments and employing both qualitative and quantitative characterization—including the molybdenum blue method and multi-phasic biochemical analysis—we identified ten high-performing isolates from the Pseudomonas, Bacillus, and Micrococcus genera. A notable discrepancy was observed between solid-media halo zones and liquid-broth efficiency, confirming the "Nautiyal effect" and highlighting that acid diffusion rates in solid media may underestimate true phosphate solubilizing metabolic potential. Specifically, Isolate I₄₇ (Pseudomonas strain) demonstrated an exceptional quantitative solubilization capacity, marking it as a superior candidate for agricultural application. These resilient, locally adapted bacteria represent a promising biological toolkit for developing cost-effective bio-fertilizers. By enhancing the bioavailability of mineral-locked phosphorus, these isolates offer a sustainable strategy to improve soil fertility and increase crop productivity in phosphorus-fixing tropical ecosystems.