Universiti Teknologi Mara carbon dioxide sequestration via immobilized carbonic anhydrase

Carbonic Anhydrase (CA) was immobilized within amberlite XAD 7 and characterized for carbon dioxide sequestration purposes. The catalytic activities for free and immobilized CA were estimated by using para-Nitrophenyl Acetate (p-NPA) as the substrate. The activities were estimated by using tris-buffer containing 10% of Acetonitrile. Lineweaver-Burk plot was employed to estimate the Michaelis-Menten kinetic parameters for both free and immobilized enzyme. The value of kinetic constants (Km and Vmax) of free and immobilized CA were 2.92 mM and 5.7 mM respectively. Meanwhile the value of Vmax and Km of free and immobilized CA were 5.95 μmoles/min/ml and 2.67 μmoles/min/ml respectively. The optimum pH for free enzyme was found to be at pH 9 while immobilized CA found to be at pH 10. The optimum temperature on the other hand, for free was at 25°C while immobilized work effectively at temperature 50°C. Then, both free and immobilized CA was employed in CaCO3 precipitation reaction in a different temperature. It was observed that carbonation reaction for free enzyme work optimum at 50°C, 70°C and 85°C. For immobilized CA, the carbonation reaction work optimum at temperature 70°C and 85°C. It was concluded that immobilized CA can be used in carbon dioxide sequestration for the purpose of converting the CO2 into valuable calcium carbonate that can be used in many processes industries.