Abstract
Bacillus cereus is an important food-borne pathogen for which effective biocontrol and rapid detection strategies are needed. In this study, a novel B. cereus-infecting bacteriophage, BCP01, was isolated from sewage and characterized together with its phage-derived endolysin and cell wall-binding domain (CBD). BCP01 exhibited myoviral morphology, strong lytic activity against B. cereus ATCC 14579, and stability over a broad range of pH and temperature conditions. Genome analysis showed that BCP01 possessed a 157,958-bp double-stranded DNA genome containing 225 predicted open reading frames and no toxin- or virulence-associated genes. A putative endolysin gene, LysBCP01, encoding a modular protein with an N-terminal amidase domain and a C-terminal SH3_5 domain, was identified and heterologously expressed. Recombinant LysBCP01 showed broader lytic activity than the parental phage against several Bacillus strains and retained activity over a broad range of pH and temperature conditions. In food matrix assays, BCP01 reduced B. cereus counts in sterile cabbage, whereas LysBCP01 reduced viable cells in both cabbage and milk. To evaluate detection applicability, the CBD of LysBCP01 was fused to enhanced green fluorescence protein (EGFP). The resulting EGFP-LysBCP01_CBD showed a host-binding range identical to the lytic spectrum of LysBCP01 and enabled fluorescence-based detection of B. cereus in milk within 5 min. These findings suggest that bacteriophage BCP01 provides multifunctional phage-derived components applicable to both biocontrol and rapid detection of food-borne B. cereus.