Characterization of immobilized glucose oxidase, immobilized catalase and CO-immobilized glucose oxidase-catalase

ABSTRACT PhD THESIS CHARACTERIZATION OF IMMOBILIZED GLUCOSE OXIDASE, IMMOBILIZED CATALASE AND CO-IMMOBILIZED GLUCOSE OXIDASE-CATALASE Gül OZYILMAZ University Of Çukurova Institute of Natural and Applied Sciences DEPARTMENT OF CHEMISTRY Supervisor: Prof.Dr. S.Seyhan TUKEL Year: 2005 Pages: 158 Jury : Prof. Dr. S.Seyhan TÜKEL Prof. Dr. Levent KAYRIN Assoc. Prof. Dr. Güzide YÜCEBİLGİÇ Assoc. Prof. Dr. Mahmut ÇALIŞKAN Assist. Prof. Dr. Ramazan BİLGİN Glucose oxidase (GOD), catalase (CAT) and glucose oxidase-catalase (GOD-CAT) were covalently immobilized onto florisil activated with glutaraldehyde at predetermined optimal immobilization conditions. GOD and CAT were co- immobilized either sequentially or simultaneously. Maximum catalytic efficiencies of the immobilized GOD, immobilized CAT and co-immobilized GOD-CAT were determined as 2.2x 103, 4.8xl04 ve 2.8xl03 s^.M"1, respectively. The higher catalytic efficiency observed with the dual enzyme system shows the advantage and efficiency of the GOD-CAT co-immobilization indicating the protective role of CAT on GOD against H2O2 inhibition. Thermal stabilities, storage stabilities at different conditions and reusability of preparations were also investigated. The catalytical efficiencies and costs of sequentially or simultaneously co-immobilized GOD-CAT systems were compared, and sequential co-immobilization was found to be more effective and cheap. Immobilized GOD, the mixture of immobilized GOD + immobilized CAT and co-immobilized GOD-CAT enzyme samples were used at batch, recycled and continuous packed bed column reactors. It was determined that co-immobilized GOD-CAT had the highest catalytic efficiency at all reactors and recycled packed bed reactor was better then the others with the highest productivities obtained for the three enzyme systems. Keywords: Glucose oxidase, catalase, florisil, covalent immobilization, co- Immobilization II