Phosphate Solubilizing Bacteria

Phosphate Solubilizing Bacteria (PSB) specifications include a minimum bacterial colony-forming unit (CFU) count of 10^7 to 10^8 per ml (liquid) or per gram (solid), and a minimum solubilization capacity, often measured as a halo zone of 5mm or a percentage increase in soluble phosphorus (P) of 30% in culture media. The bacterial strains themselves are characterized by their ability to produce organic acids and enzymes like acid phosphatase and pyrophosphatase, which convert insoluble phosphates (e.g., tricalcium phosphate, rock phosphate) into plant-available forms.