Der Einfluss minimaler Mengen Sauerstoff auf die Vergärung der Glukose durch die Kulturweinhefe «Fendant»

Summary

This study deals with the effect of minute amounts of oxygen upon the fermentation of glucose by resting cells of the tame wine yeast Fendant grown for 17 and 66 h, respectively, in a synthetic substrate containing glucose, vitamin-free casein hydrolysate, citrate buffer and mineral salts. The results prove conclusively the dependence of the metabolic activity of the yeast cells from young cultures on the duration of flushing with oxygen-free nitrogen or argon before the addition of glucose, the rate of carbon dioxide production in the approximately linear phase of fermentation decreasing considerably with increasing flushing times. This inactivation of the cells is removed, as a whole or partly, at oxygen tensions greater than 0.01–0.05% by volume. Resting cells from old Fendant cultures show the effects mentioned only to a very small extent. It is assumed that in resting cells from young Fendant yeast cultures one or more components of the zymase system are inactivated on flushing with nitrogen or argon. The activity is restored, quantitatively or partly, by minute amounts of oxygen introduced prior to the addition of glucose.