The positive recombinant strains(Mut+) were obtained by MM and MD plate and PCR analysis.

• 获得的菌体经超声破壁、硫酸铵沉淀得粗酶，再利用金属Ni螯和型树脂经一步分离纯化得到可转化头孢菌素C制备GL-7-ACA的DAAO。