Mode of action of pentocin 31-1: An antilisteria bacteriocin produced by Lactobacillus pentosus from Chinese traditional ham

Lactobicillus pentosus 31-1, isolated from Chinese traditional ham, produced a bacteriocin active against Gram-positive bacteria including Listeria spp. The bacteriocin, named pentocin 31-1, has been purified by ammonium sulphate precipitation, SP-Sepharose Fast Flow and SDS–PAGE. Results from killing assays performed with pentocin 31-1 suggest that the action of the bacteriocin was enhanced when target cells were energized. The addition of 0.0625 mg ml−1 of pentocin 31-1 to energized cells of Listeria monocytogenes NICPBP 54002 lead to efflux of UV-absorbing materials, K+ ions, inorganic phosphate and ATP, resulting in a collapse of ΔΨ and ΔpH. These data indicated that the bacteriocin influences cells by making sensitive cell membranes permeable. Therefore, it may be useful to improve the safety of food products.