【摘要】 部分纯化的变异三角酵母D-氨基酸氧化酶(DAO)在碱性条件下变性过氧化氢酶,再与大孔聚甲基丙烯酸缩水甘油酯高聚物共价交联。与游离酶相比,固定化酶的最适反应温度升高,最适pH范围变宽,对温度和pH的稳定性都有明显的提高。固定化DAO在搅拌反应器中催化头孢霉素C(CPC)转化为戊二酰基-7-氨基头孢霉烷酸(Gl-7-ACA)。以0.03g/mL的CPC为底物,在温度25℃、pH7.2条件下,产物的得率>93%,副产物得率<5%。经过110批反应后,固定化酶保持64%的初始活力。更多还原

【Abstract】 Damino acid oxidase (DAO) from Trigonopsis variabilis was treated at pH 11.0 to deactivate catalyst presented in partially purified preparation, and then covalently immobilized to Epresin, a maroporous glycidal methacrylateN, N′methylenebis( arcylamide) copolymers. The immobilized enzyme exhibited a wider optimum pH and a much higher temperature compared to the native one, and showed a marked enhancement of stability against thermal and pH inactivation as well. The immobilized DAO was used for the production of glutaryl7aminocephalosporanic acid (Gl7ACA) from cephalosporin C (CPC) in a stirred tank reactor. A conversion of >93 %, with byproduct formation <5%, was achieved by using 0.03 g/mL solution of CPC at pH 7.2 and 25℃. The reaction was repeated for 110 cycles, and the enzyme preserved 64% of the initial activity.更多还原