Design, characterization, and application of novel antimicrobial peptides against Bacillus cereus

Foodborne pathogens such as Bacillus cereus threaten food safety, necessitating novel antimicrobial solutions. Antimicrobial peptides (AMPs) offer broad-spectrum activity and potential applications in food preservation. In this study, we designed a library of candidate AMPs by leveraging the sequence and structural conservation of the host defense peptides (HDPs). Specifically, we designed a virtual library of potential AMP sequences based on the amino acid consensus pattern of the γ-core sequence isoform, represented by the formula [KR]GG[KR]XC[FWY]C[KR]X[KR][FWY]C[LIAV]CXG[KR][KR]. By integrating a machine-learning-based recognition model with bioactivity assays, we screened and identified a group of AMPs effective against B. cereus. Among these, peptide XWC26 demonstrated the strongest inhibitory activity, with a minimum inhibitory concentration (MIC) of 2 μg/mL. XWC26 showed rapid, broad-spectrum bactericidal activity and excellent stability. It can effectively eliminate B. cereus within 10 min at its MIC and inhibits spore germination at 16 μg/mL. Mechanistic studies revealed that XWC26 disrupts the bacterial cell membrane, leading to rapid cell death. Furthermore, in B. cereus-contaminated rice, XWC26 eradicated B. cereus within 2 h at 16 μg/mL. These results underscore the potential of designed AMPs as powerful antimicrobial agents, with XWC26 standing out as a promising candidate for enhancing food safety.