Lactococcus lactis is a bacteria with a high potential of bioactive peptide production. One of the most important activities of these peptides is metal chelating activity especially of calcium, iron and zinc. The aim of this work was evaluated the effect of pH on calcium and iron chelating peptides production in fermentations by Lactoccocus lactis subsp. cremoris NCFB 712. It was observed that during fermentation with pH control, the production of calcium binding peptides (0.28 mmol Ca² mg^-1 protein) was improved, with respect to fermentation without pH control (0.23 mmol Ca²⁺ mg^-1 protein). There is a correlation between proteolytic activity and calcium-binding activity by the supernatants of fermentations with or without pH control. As for the iron-binding activity was observed an increase in the fermentation with pH control with respect to fermentation without control, which was maintained as the initial binding activity characteristic of the milk proteins. It was found that the molecular weights of some of the peptides generated match with the sequence reported molecular weights and calcium and iron binding.