A Rapid Method for Isolation and Screening of Phosphate Solubilizing Bacteria

摘要

Phosphorus is the second major plant-nutrient limiting the plant productivity. Phosphorus isrnpresent in unusable form and P solubilizing microorganisms play an important role in solubilizingrnthe insoluble P and thereby enhancing the plant growth and productivity. In the presentrninvestigation a modified method for rapid and accurate isolation and screening of phosphaternsolubilizing bacteria (PSB) was developed. Thirty four isolates of PSB, from rhizosphere of chickpearnand wheat were isolated based on size halo zone formed (P solubilization efficiency) on Rikivskayasrnmedium . Out of the various media reported for such studied NBRIP medium was found to bernslightly better than others. Among the various constituents tested, Glucose (NH4)2 SO4 showed highrnrate of P-solubilization at neutral pH and 30℃ ±2℃ incubation temperature. Increase inrnconcentration of bacterial cell enormously decreased the time taken for P-solubilization. Addition ofrnbromothymol blue further improved the early detection of PSB activity under laboratory conditions.