Authors : Roshan N. Kamanwar, Ashok V. Gomashe
Page Nos : 8
An investigation was conducted on the immobilization of β-D-galactosidase onto chitosan and characterized based on its optimal operation pH and temperature, its thermal stability and its kinetic parameters (Km and Vmax) using onitrophenyl β-d-galactopyranoside as substrate. The optimal pH for free β-D-galactosidase activity and immobilized βD-galactosidase was found to be 7.3 but the immobilized enzyme worked at broader range of pH. Optimal operating temperatures of free β-D-galactosidase and immobilized β-D-galactosidase found to be 37 ◦C. At 55◦C, the immobilized enzyme showed an increased thermal stability, being more stable than the soluble enzyme retaining 60% of its initial activity. The immobilized enzyme was reused for 10 cycles, showing stability since it retained more than 70% of its initial activity. The immobilized enzyme retained approximately 100% of its initial activity when it was stored at 4°C and pH 7.0 for 30 days. The soluble β-gal lost more than 10 % of its initial activity when it was stored at the same conditions.