OPTIMIZATION OF EXTRACELLULAR TANNASE PRODUCTION BY ASPERGILLUS NIGER VAN TIEGHEM USING RESPONSE SURFACE METHODOLOGY

Abstract

Response surface methodology (RSM) was used to optimize the production of tannase by a newly isolate of Aspergillus niger Van Tieghem using rotatable central composite design (RCCD). This statistical optimization process was carried out involving four of quantitative growth parameters (variables), namely tannic acid concentration, nitrogen source concentration, initial pH of the medium and inoculum size. A mathematical model expressing the production process of tannase by submerged fermentation (SmF) technique was generated statistically in the form of a second order polynomial equation. The model indicated the presence of significant linear, quadratic and interaction effects of the studied variables on tannase production by the fungal isolate. The results showed maximum tannase production (580 U/50 ml medium) at 2% tannic acid, 4 g/l sodium nitrate, pH 4 and inoculum size of 5×107 spores/50 ml medium, which was also verified by experimental data.