A probiotic bacterium, Pediococcus pentosaceus OZF, isolated from human breast milk produces pediocin AcH/PA-1

Pediococcus pentosaceus OZF, originally isolated from healthy human breast milk, produces antimicrobial activities against many gram-positive bacterial species, including the food borne pathogen, Listeria monocytogenes. A bacteriocin was purified to homogeneity from the supernatant of exponentially growing cells using ion-exchange and reversed-phase chromatography. The purification resulted in a high recovery and an approximately 224.000 fold increase in specific activity. The molecular mass of the bacteriocin was 4,623 Da as determined by electrospray ionization mass spectrometry. Based on the DNA sequences of the pediocin AcH/PA-1 operon, specific primers were synthesized and used to determine whether the purified pediocin was identical to another previously reported bacteriocin. Results show that the bacteriocin produced by P. pentosaceus OZF was identical to pediocin AcH/PA-1. We thus refer to the identified bacteriocin as pediocin AcH/PA-1 in order to avoid confusion. The value of this report is that the producer strain is shown to be distinct from the pediocin PA-1 producer (P. pentosaceus PA-1) based on a sugar fermentation profile.Key words: Pediococcus pentosaceus, pediocin, purification, characterization