Role of metal ions, EDT A and phosphatase enzyme during the solubilisation of Indian rock phosphate by Aspergillus niger

Department of Chemical Engineering, Biochemical Engineering Division, University of Calcutta,

92, Acharya Prafulla Chandra Road, Kolkata-700 009, India

E-mail : subhadeepgangulyphysiol@rediffmail.com

Manuscript received 11 November 2011, accepted 31 January 2012

The process of solubilisation of rock phosphate by a mutant strain of Aspergillus niger AB₁₀₀ was stimulated by adding FeSO₄. 7H₂O to the incubation medium. EDTA at a concentration of 30 mg/ml greatly enhanced the solubilisation process whereas CaCO₃ (0.5-2.0%) and znso4. 7H₂O inhibited the process. Phosphatase activity and acid production was found to vary directly with the solubilisation process.