Abstract: Escherichia coli O157∶H7 is a common foodborne pathogen that severely threatens public health. Phage, endolysin and holin are new bacteriostatic agents. In this study, phage EC-p9 was identified by random primer for decammeric oligonucleotide, genes of endolysin Lys 9 and holin Hol 9 of the phage were obtained through PCR, properties of the two proteins were predicted through in-silico analysis, and the two proteins were expressed by E.coli. The results indicated that phage EC-p9 was dsDNA phage with a “holin-endolysin” lysis system. Endolysin Lys 9 was a peptidoglycan hydrolase without a transmembrane structure. Holin Hol 9 was a type III holin with only one transmembrane structure. Endolysin Lys 9 and holin Hol 9 were successfully expressed in E.coli BL21 (DE3), with yield of 2.49 and 0.95 g/L, respectively. Only limited amount of holin Hol 9 was obtained due to its toxic effect on E.coli. The results laid a foundation for research of the bacteriostatic ability of endolysin Lys 9 and holin Hol 9, and also for investigation of the lysis system of phage EC-p9.
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