Biogenic amines occurrence in wine amino acid decarboxylase and proteolytic activities expression by Oenococcus oeni

This work deals with the study of the proteolytic and amino acid decarboxyl ase activities of selected Oenococcus oeni isolates and the effect of yeast autolysis on biogenic amines production in wine. A total of 220 isolates o f O. oeni were tested for decarboxylase and proteolytic activity. Only six isolates showed both activities, but only after a period of adaptation ina growth medium containing wine. The results reported on this paper show that proteolytic activity was dependent; on medium composition and bacterial gr owth phase. It can be assumed that the ability of O. oeni to use wine pepti des and to produce biogenic amines is not a constant characteristic of this species, and enzymatic system expression appears to be closely dependent o n nutritional and energetical composition of the medium. It also seems to b e strain dependent and not widespread among this bacterial community.