Antimicrobial activity of pediocin PA-1 against Oenococcus oeni and other wine bacteria

Pediocin PA-1 is an antimicrobial peptide produced by lactic acid bacteria (LAB) that has been sufficiently well characterised to be used in food industry as a biopreservative. Sulphur dioxide is the traditional antimicrobial agent used during the winemaking process to control bacterial growth and wine spoilage. In this study, we describe the effect of pediocin PA-1 alone and in combination with sulphur dioxide and ethanol on the growth of a collection of 53 oenological LAB, 18 acetic acid bacteria and 16 yeast strains; in addition, production of pediocin PA-1 by Pediococcus acidilactici J347-29 in presence of ethanol and grape must is also reported. Inhibitory concentrations (IC) and minimal bactericide concentrations of pediocin PA-1 were determined against LAB, and revealed a bacteriostatic effect. Oenococcus oeni resulted more sensitive to pediocin PA-1 (IC₅₀ = 19 ng/ml) than the other LAB species (IC₅₀ = 312 ng/ml). Cooperative inhibitory effects of pediocin PA-1 and either sulphur dioxide or ethanol were observed on LAB growth. Moreover, the pediocin PA-1 producing P. acidilactici strain J347-29 was able to grow and produce the bacteriocin in presence of ethanol (up to 4% ethanol in the fermentation broth) and grape must (up to 80%), which indicated that pediocin PA-1 can be considered as a potential biopreservative in winemaking.