Lysis of yeast cells by Oenococcus oeni enzymes

Oenococcus oeni exhibited extracellular beta (1-->3) glucanase activity. Th is activity increased when cells were cultivated with glycosidic cell-wall macromolecules. In addition, the culture supernatant of the organism effect ively lysed viable or dead cells of Saccharomyces cerevisiae. This lytic ac tivity appeared in the early stationary phase of bacterial growth. Yeast ce lls at the end of the log phase of growth were the most sensitive. The opti mum temperature for lysis of viable yeast cells was 40 degreesC, which is v ery different from the temperatures observed in enological conditions (15-2 0 degreesC). Moreover, the rate of the lytic activity was significantly low er in comparison with yeast cell wall-degrading activities previously measu red in various other microorganisms. Therefore, yeast cell death that is so metimes observed during the alcoholic fermentation could hardly be attribut ed to the lytic activity of O. oeni.