RESUMEN
Urease enzyme was isolated from Proteus mirabilis and immobilized in alginate beads. Various parameters such as optimum pH, optimum temperature, pH stability, thermal stability, reusability, storage stability and substrate concentration were investigated and the findings were compared with free urease enzyme. İmmobilization yield was calculated as 85 %. Optimum temperature was found to be 40°C for free and immobilized urease. Thermal stability of the immobilized urease enzyme was significantly better than the free enzyme. Optimum pH for free and immobilized urease was be 7.0. Immobilized and free urease enzymes protected their stability at pH 7.0 and 8.0 in a similar way. Immobilized enzyme maintained 55% of their initial activity after 12 repeated use of enzyme. It was found that storage stability of immobilized enzyme was better than that of free enzyme. Km and Vmax values from the Lineweaver-Burk plots were calculated.