TY - JOUR JF - انستیتو-پاستور-ایران JO - IBJ VL - 26 IS - 2 PY - 2022 Y1 - 2022/3/01 TI - Immobilization of Urease onto Modified Egg Shell Membrane through Cross Linking TT - N2 - Background: Immobilization is an approach in industry to improve stability and reusability of urease. The efficiency of this technique depends on the type of membrane and the method of stabilization. Methods: The PEI-modified egg shell membrane was used to immobilize urease by absorption and glutaraldehyde cross-linking methods. The membranes were characterized by Fourier-transform infrared spectroscopy (FTIR) and AFM, and Nessler method was applied to measure the kinetic of the immobilized enzymes. Finally, the storage stability (6 °C for 21 days) and reusability (until enzyme activity reached to zero) of the immobilized enzymes were investigated. Results: Based on FTIR, three new peaks were observed in both the absorption- (at 1389.7, 1230.8, and 1074.2 cm-1) and the cross-linking (at 1615-1690, 1392.7, 1450 cm-1) immobilized enzymes. The surface roughness of the native membrane was altered after PEI treatment and enzyme immobilization. The optimal pH of cross-linking immobilized enzymes was shifted to a more neutral pH, while it was alkaline in adsorption-immobilized and free enzymes. The reaction time decreased in all immobilized enzymes (100 min for free enzyme vs. 60 and 30 min after immobilizing by adsorption and cross-linking methods, respectively). The optimal temperature for all enzymes was 70 °C and they had a higher Km and a lower Vmax than free enzyme. The stability and reusability of urease were improved by both methods. Conclusion: Our findings propose these approaches as promising ways to enhance the urease efficiency for its applications in industries and medicines. SP - 132 EP - 141 AU - Morovvat, Fatemeh AU - Samsam Shariat*, Seyed Ziaeddin AU - Davoudi, Maryam AU - Norouzian, Dariush AD - Pilot Nano- Biotechnology Department- Pasteur Institute of Iran KW - Egg shell KW - Immobilization KW - Polyethylenimine KW - Urease UR - http://ibj.pasteur.ac.ir/article-1-2869-en.html DO - 10.52547/ibj.26.2.132 ER -