PHYSICAL AND CHEMICAL FACTORS AFFECTING THE RELEASE OF SILICA FROM MAGNESITE ORE BY A BACILLUS SP.

Abstract

The present investigations were undertaken to determine the effect of many physical and chemical factors on the silica solubilizing activity of a species of Bacillus. The bacteria, previously reported to release silica from magnesite ore, was found to do so at an optimum temperature of 37°C. Changing the temperature inhibited the silica release. An optimum shaking condition of 50-100 r.p.m. was suitable for maximum silica release. The best results were obtained with a medium containing ammonium sulfate, yeast extract among the nitrogen sources, disodium hydrogen phosphate and potassium dihydrogen phosphate as phosphate sources, magnesium sulfate and manganese sulfate as divalent cations. An incubation period of 8 days was favourable for maximum silica release by the microorganism.