Abstract
Biosilica from rice husk ash can be used to immobilize enzyme by sol-gel entrapment method. Cellulase was chosen as the probe enzyme to test the feasibility of this material for such purpose. This research aimed to know the optimum condition of cellulase immobilization process by sol-gel entrapment, the optimum pH and temperature for immobilized enzyme, and the reusability of the immobilized enzyme, as concluded from its activity. The research was divided into 3 steps (1) sol-gel immobilization of cellulase, (2) protein and activity experiments to test immobilized enzyme by varying pH and temperature, and (3) reusability test. The result showed optimum condition gave 38.48 % recovery of enzyme activity with protein content of 0.42 mg·mL-1, the best pH and temperature were 7 and 55 0C respectively. The system could be reused for three times.