Novel support of MCM-48 molecular sieve for immobilization of penicillin G acylase

As a novel support of immobilizing penicillin G acylase (PGA), MCM-48 and Co-MCM-48 molecular sieves were synthesized and characterized by XRD, N-2 adsorption, NH3-TPD, FT-IR and so on. The studies show that MCM-48 and Co-MCM-48 has well ordered long-range structure, narrow pore size distribution, larger surface area and higher concentration of the weakly acidic silanol groups on their surface. Penicillin G acylase was immobilized on MCM-48 or Co-MCM-48 by interacting silanol groups on the surface. The presence of cobalt in the framework of MCM-48 increases the amount of the weak acid sites. For the hydrolysis of penicillin G catalyzed by PGA/Co-MCM-48 (Co/Si = 0.01), its specific activity reaches 1682 U/g. After used for six cycles, PGA/MCM-48(0.01) can keep 1375 U/g of the specific activity. If MCM-41 was used as the support, the activity of immobilized PGA is only 402 U/g. (C) 2004 Elsevier B.V. All rights reserved.