The current study was conducted to explore the potential of a phosphate solubilizing for the preparation of high quality
phosphate fertilizer by bioleaching from low grade Egyptian ore. Bacillus megaterium, Rhizobium rhizogenes and
Thiobacillus thiooxidans were evaluated for their ability to phosphate dissolution from Egyptian Sebaiya west low-grade
phosphate ore by studying optimization conditions of incubation temperature, incubation time and inoculum size, pH and
different carbon and nitrogen as energy sources. Results revealed that dissolution of P2O5 reached to 19.9, 68.4 and 32.2
for B. megaterium, R. rhizogenes and T. thiooxidans respectively. A model has been suggested which assumes that the
phosphate radical was attacked by the reducing bacteria to produce unstable soluble phosphorus ions that readily
oxidized to P2O5 with water oxygen. Kinetically, the leaching process was a zero-order reaction. In this work applied of
microorganism in industrial processes was practically feasible with low cost and friendly environmental process.