Bovine liver catalase was covalently immobilized onto controlled pore glass (CPG) beads modified with 3-aminopropyltriethoxysilane (3-APTES) followed by treatment with glutaraldehyde. Coupling of catalase onto CPG was optimized to improve the efficiency of the overall immobilization procedure. The optimum coupling conditions: pore diameter of CPG, pH. buffer concentration, temperature, coupling time and initial catalase amount per grams of carrier were determined as 70 nm, 6.0, 75 mM, 5 degrees C, 7 h and 6mg catalase, respectively. Catalytic efficiencies (k(cat)/K-m) and thermal inactivation rate constants (k(i)) of ICPG1 were determined and compared with that of free catalase. Suitability of ICPG1 was also investigated by using it in batch and plug-flow type reactors. When the remaining activity of ICPG1 retained was about 50% of its initial activity the highest total productivity of ICPG1 was determined as 7.6 x 10(6) U g immobilized catalase(-1) in plug-flow type reactor. However, the highest total productivity of ICPG1 was 6.2 x 10(5) U g immobilized catalase-1 in batch type reactor. ICPG1 may have great potentials as biocatalyst for the application in decomposition of hydrogen peroxide in plug-flow type reactor. (C) 2008 Elsevier B.V. All rights reserved.