The current study was conducted to explore the potential of potassium solubilizing for the plant fromGluconite Egyptian ore. Thiobacillus thiooxidans, Rhizobium leguminosarum, Rhizobium rhizogenes and
Bacillus megaterium were evaluated for their ability to potassium dissolution from Egyptian Gluconite 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 potassium reached to
30.66, 31,66, 34.44 and 28.87 for Thiobacillus thiooxidans, Rhizobium leguminosarum, Rhizobiumrhizogenes and Bacillus megaterium respectively. A model has been suggested which assumes that the
potassium was attacked by the reducing bacteria to produce potassium ions of produced organic acids.
Kinetically, the leaching process was a zeroorder reaction. In this work applied of microorganism in
industrial processes was practically feasible with low cost and friendly environmental process.