Characterization of an endolysin, LysBPS13, from a Bacillus cereus bacteriophage

Use of bacteriophages as biocontrol agents is a promising tool for controlling pathogenic bacteria including antibiotic-resistant bacteria. Not only bacteriophages but also endolysins, the peptidoglycan hydrolyzing enzymes encoded by bacteriophages, have high potential for applications as biocontrol agents against food-borne pathogens. In this study, a putative endolysin gene was identified in the genome of the bacteriophage BPS13, which infects Bacillus cereus. In silico analysis of this endolysin, designated LysBPS13, showed that it consists of an N-terminal catalytic domain (PGRP domain) and a C-terminal cell wall binding domain (SH3_5 domain). Further characterization of the purified LysBPS13 revealed that this endolysin is an N-acetylmuramyl-l-alanine amidase, the activity of which was not influenced by addition of EDTA. In addition, LysBPS13 demonstrated remarkable thermostability in the presence of glycerol, and it retained its lytic activity even after incubation at 100 °C for 30 min. Taken together, these results indicate that LysBPS13 can be considered a favorable candidate for a new antimicrobial agent to control B. cereus.