Peptidases specific for proline-containing peptides and their unusual peptide-dependent regulation in Oenococcus oeni

International audience; Growth of the lactic acid bacterium (LAB) Oenococcus oeni, which is involved in malolactic fermentation during the winemaking process, is stimulated by peptides originating from yeast. In this study, we investigated the impact of peptides on O. oeni growth, peptidase activity and the expression of genes encoding the studied peptidases. Low levels of PepN activity and very high levels of PepI activity were observed in O. oeni, whereas levels of PepX activity were intermediate. The level of biosynthesis of these O. oeni peptidases was shown to depend on peptides present in the culture medium. These results were confirmed by transcriptional analyses of putative pep gene…