利用反相悬浮技术制备出平均孔径和比表面积分别为13.0 nm和123.6 m²/g的磁性聚合物微球，其具有超顺磁性，饱和磁化强度为6.04 emu/g。磁性微球固定化青霉素G酰化酶在乙二醇-磷酸盐缓冲溶液共溶剂体系中催化7-氨基-3-氯-3-头孢烯-4-酸（7-ACCA）与D-苯甘氨酸甲酯（D-PGM）合成头孢克洛，20℃反应2 h时，头孢克洛产率为33.0%，合成与水解比（S/H）为0.13；而在相同反应条件下使用游离青霉素G酰化酶，产率和合成与水解比分别为17.0%和0.08。同时考察了酶用量、反应温度以及溶剂对磁性固定化酶催化合成头孢克洛性能的影响规律。

The magnetic polymer microspheres,with an average pore diameter of 13.0 nm and a specific surface area of 123.6 m²·g^-1,are synthesized by inverse suspension polymerization method.The prepared microspheres exhibit super paramagnetism for the immobilization of penicillin G acylase (PGA),with saturation magnetization of 6.04 emu·g^-1.Cefaclor is synthesized by catalytic reaction between 7-amino-3-chloro-cephems-3-en-4-acid (7-ACCA) and D-phenyl glycine methyl ester (D-PGM) over the magnetic polymer microspheres-immobilized PGA in ethylene glycol-phosphate buffer solvent system.The yield of cefaclor reaches 33.0% after the reaction has performed for 2 h at 20℃,and the molar ratio of synthesis to hydrolysis (S/H) is 0.13 after reaction.The yield of cephalexin and the S/H value are 17.0% and 0.08 respectively while the free penicillin G acylase is used under the same reaction conditions.The effects of enzyme content,reaction temperature and solvent on cefaclor synthesis over the magnetic immobilized PGA are studied.

胡春苗(1995-),女,在读硕士研究生,研究方向为功能材料与生物催化,h13629512963@163.com