Antimicrobial mechanism of Temporin L peptide against Bacillus cereus

Bacillus cereus ( B. cereus ) is a common foodborne pathogen causing emetic and diarrheal syndromes. This study investigates the antimicrobial mechanism of Temporin L, an antimicrobial peptide (AMP), against B. cereus . The minimum inhibitory concentration and minimum bactericidal concentration of Temporin L against B. cereus were determined to be 8 µM and 16 µM, respectively. The antimicrobial mechanisms of Temporin L were investigated, including cell wall disruption (extracellular AKP activity), changes in cell morphology, increase in membrane permeability (PI uptake and leakage of protein and nucleic acid), metabolic impacts (Na⁺K⁺-ATPase, SDH, and LDH enzyme activities), and oxidative stress induction (ROS content, T-AOC, MDA, and SOD levels). Temporin L exhibited pH-dependent inhibitory activity, maintained its inhibitory activity even after exposure to 100°C for extended periods of up to 60 min, and was stable under UV irradiation. The findings suggest that Temporin L antimicrobial activity involves multiple mechanisms, making it a promising candidate for food preservation and safety applications.