Objective    To construct

express and purify recombinant endolysin of Pseudomonas aeruginosa (P. aeruginosa) bacteriophage PaP1

and detect its enzymatic activity and antibacterial activity.     Methods    The objective endolysin fragment of bacteriophage PaP1 was amplified from the genome

and then cloned into the expression vector pQE31. Then the fusion protein expressed in E.coli M15(pREP4) and purified under native conditions. The enzymatic activity was detected by zymography assay and its biological activity was detected by antibacterial activity assay.     Results    Enzymatic assay showed that the recombinant protein could cause the lysis of the purified P. aeruginosa peptidoglycan. Antibacterial activity assay showed that the recombinant protein inhibited the growth of Staphylococcus aureus.     Conclusion    The obtained phage endolysin exerts antibacterial activity to P. aeruginosa.