Magnetic nanocrystalline cellulose (MNCC) was prepared and used as an enzyme support for the immobilization of penicillin acylase (PA). A novel coupling agent, tri(hydroxymethyl)phosphine(THP) instead of the conventional glutaraldehyde(GA), was used as a crosslinker in this study. The obtained results showed that the immobilized PA with THP (PA-THP-MNCC) had high enzyme loading (172.3 mg/g) and activity recovery (77.6%) in the optimal preparation conditions, which were remarkably superior to those of the counterpart using GA (PA-GA-MNCC, 148.4 mg/g and 48.7%, respectively). Compared with free PA and PA-GA-MNCC, PA-THP-MNCC displayed a higher optimum pH and temperature, and manifested relatively higher enzyme-substrate affinity and catalytic efficiency. In addition, PA-THP-MNCC exhibited significantly enhanced stability. Furthermore, PA-THP-MNCC was successfully employed for synthesis of cefaclor, an important second-generation cephalosporin antibiotic, affording a significantly higher yield of 84% than that reported previously.

制备了磁性纳米晶体纤维素（MNCC），并用作固定青霉素酰基转移酶（PA）的酶载体。本研究使用新型偶联剂三（羟甲基）膦（THP）代替常规戊二醛（GA）作为交联剂。获得的结果表明，在最佳制备条件下，THP固定化的PA（PA-THP-MNCC）具有较高的酶载量（172.3 mg / g）和活性回收率（77.6％），明显优于使用GA（PA-GA-MNCC，分别为148.4 mg / g和48.7％）。与游离PA和PA-GA-MNCC相比，PA-THP-MNCC具有更高的最佳pH和温度，并表现出相对更高的酶-底物亲和力和催化效率。另外，PA-THP-MNCC表现出显着增强的稳定性。此外，