Isolation and Screening of Phosphate Solubilizing Bacteria from Paddy Rhizosphere Soil

Phosphorus is one of essential macro-minerals for the growth and development of plant. The main of this study to isolate the PSB and screened for its solubilization efficiency on Pikovskaya’s agar and broth at different incubation period. Totally 40 PSB were isolated from paddy rhizosphere soils of Raichur and Koppal districts. PSB isolates were studied for zone of solubilization, solubilization efficiency, solubilization index, ph change titrable acidity and phosphatase activity. The solubilization zone, efficiency and index were highest on 6th day of incubation period. From that 10 isolates were found to be good phosphate solubilizer. Among 10 isolates, isolate PPSB-21 showed highest zone of solubilization (18.4 mm) phosphate solubilization efficiency (253.84%) and solubilization index (3.53) on Pikovsakaya’s medium. These efficient isolates can be used as biofertilizer.