Protease activity of Oenococcus oeni viable cells on red wine nitrogenous macromolecular fraction in presence of SO2 and ethanol

The protease activity of Oenococcus oeni X2L viable cells on red wine nitrogenous macromolecular fraction (NMF) as sole nitrogen source was determined. The enzyme releases growth factors for Oenococcus oeni. In presence of SO2 and ethanol the rate of amino acids liberation was twofold higher. A peptide peak analyzed by HPLC with a retention time of 47 min diminishes markedly during the first 2 h incubation. O. oeni X2L living cells are able to produce the exoprotease and to act on the red wine NMF in the presence of SO2 and ethanol releasing essential amino acids for its survival.