The aim of this study was to understand the mechanism of potassium release from inert source of potassium (waste mica or vermiculite) inoculated with potassium solubilising bacteria (isolate-101). The isolate was examined for its K solubilising ability and pH change of broth at 5, 10, 15, 20, 25 and 30 days of incubation and found that solubilisation of K in the mica containing broth was at the rate of 31.6, 38.8, 42.45, 47.92 and 48.1 mg/ml at respective incubation periods. The corresponding pH change in broth was found to be 7.34, 6.44, 6.24, 6.16, 6.15 and 6.15 at respective periods of incubation. Similarly, bacterial inoculation resulted in release of significant amount of K ions in vermiculite amended broth over the uninoculated control. HPLC analysis of the bacterial culture showed the presence of lactic acid and oxalic acid at the rate of 1.89 µl and 3.5 µl per 100 ml of broth respectively. Interestingly, an inverse relationship was found between the pH change and K release from this study and found to be more significant.