Effects of temperature, pH and additives on the activity of tannase produced by a co-culture of Rhizopus oryzae and Aspergillus foetidus

Summary Tannase was produced by modified solid-state fermentation (MSSF) of tannin rich substrates by a co-culture of the two filamentous fungi, Rhizopus oryzae and Aspergillus foetidus. The enzyme thus produced was then partially purified by solvent precipitation and DEAE-Sephadex column chromatography. A study on the effects of temperature and pH was made on the activity of tannase so purified. The optimum values of incubation time, reaction temperature and pH for tannase activity were 5 min, 40 °C and 5.0 respectively. The half-life period thermal stability and kinetic constants (K _m 0.21 mM, V _max 4.9×10⁻² M min^-1 at 40 °C) of this tannase were determined and the effects of different metal ions, surfactants, chelators, denaturants and inhibitors on the enzyme activity were also studied.