Nutritional Effect on Acid Phosphatase Activity during the Solubilisation of Indian Rock Phosphate by Aspergillus niger

Aspergillus niger treated with ethyl methane sulfonate and gamma rays was incubated with samples of rock phosphate taken from Rajasthan, India for exploring its solubilisation capacity and phosphatase activity. 4 percent glucose and 0.4 percent sodium nitrate were the best carbon and nitrogen sources respectively. 0.1 percent KCl and 0.03 percent KH₂PO₄, stimulated the solubilisation process whereas CaCO₃ inhibited it. Phosphatase activity was found to vary directly with the solubilisation process indicating that the dephosphorylation of the rock was due to the production of acid phosphatase enzyme.