Influence of pH drop on both nisin and pediocin production by Lactococcus lactis and Pediococcus acidilactici

To develop a kinetic model for describing the specific effect of pH drop on nisin and pediocin production in whey.

The effect of pH drop on both bacteriocin productions was tested in non-buffered whey and whey buffered at initial pH 6.3 with 0.03, 0.10 and 0.25 mol l-1 of potassium hydrogen phthalate-NaOH. An accurate description of the experimental data of nisin and pediocin obtained at different pH drops is obtained with the proposed model.

The proposed model was able to typify both bacteriocins as pH-dependent primary metabolites.

The decisive role of pH drop for bacteriocin production on whey was demonstrated and modelled. This study contributes to a better understanding of underlying metabolic regulatory mechanisms, which could facilitate the optimization of bacteriocin production for upscaling.