Abstract: The aim of this study is to find a virulent Listeria phage that can inactivate Listeria monocytogenes (Lm) and achieve biological control of Lm in ready-to-eat foods using the phase. The phage was isolated from sewage by double layer plate assay with agar medium. The PEG/NaCl purified phage was analyzed by electron microscope after negative staining. Host range and biological characteristics of the phage were detected. In addition, the genomic DNA was analyzed by restriction enzyme digestion. Finally, the inactivation effect of the phage on Lm in ready-to-eat foods was evaluated. The isolated phage, named as LipG2-5, was a lytic member of the Siphoviridae family, which could effectively lyse its hosts. LipG2-5 had a wide range of hosts and revealed excellent tolerance to temperature and pH. According to genomic analysis by restriction enzyme digestion, LipG2-5 was double strand DNA phage. Lm in ready-to-eat foods could be inactivated within 24 h after LipG2-5 had been added into the foods.

Key words: Listeria monocytogenes, phage, biocontrol