Purification, characterization and antimicrobial activity of pediocin PA-1 from Pediococcus acidilactici LH31

Pediocin PA-1 is a Class IIa bacteriocin with potent activity against foodborne pathogens, but its application is limited by the lack of efficient purification methods. In this study, pediocin PA-1 was purified from Pediococcus acidilactici LH31 using a two-step procedure consisting of pH-mediated cell adsorption-desorption followed by semi-preparative reversed-phase high-performance liquid chromatography. The purified bacteriocin showed a single band at approximately 5.0 kDa on Tricine-SDS-PAGE. It exhibited optimal antimicrobial activity against Enterococcus faecalis at 25 °C and pH 6.0. The bacteriocin retained significant activity after boiling for 20 min and remained stable across pH 4.0-9.0. The minimum inhibitory concentration (MIC) was determined to be 50 μg/mL. Time-kill kinetics demonstrated concentration-dependent bactericidal activity, with >3 log₁₀ reduction in viable counts within 10 h at 2× MIC. All experiments were performed in triplicate using three independent bacterial culture batches. These findings provide an efficient purification protocol for pediocin PA-1 and comprehensively characterize its stability and antimicrobial kinetics, supporting its potential as a natural food preservative.