Improving enzyme immobilization in mesocellular siliceous foams by microwave irradiation

Microwave irradiation was used to immobilize papain and penicillin acylase in mesocellular siliceous foams (MCFs) at low temperature. The maximum loading of papain reached 984.1 mg/g, 1.26 times that obtained using the conventional, non-microwave-assisted method. The half-life (t0.5) of papain immobilized in MCFs by microwave irradiation at 80°C was 17 h, 5.21 times that of papain immobilized by conventional means. The activities of papain and penicillin acylase immobilized with the microwave-assisted method were 779.6 U/mg and 141.8 U/mg respectively, 1.86 and 1.39 times of those obtained without microwave immobilization. Using microwave irradiation it only took 140 s for penicillin acylase, an enzyme of large dimensions, to be immobilized in MCFs. In contrast, it took 15 h to do the same using the conventional method. The results showed that microwave irradiation improved the adsorption and immobilization of enzymes in mesocellular siliceous foams.