[The effect of dissolved oxygen tension on the energy metabolism of yeasts].

The specific ATP generation rate in yeasts was examined on the glycolytic pathway and on the respiratory chain as a function of the dissolved oxygen tension of the culture medium. Two different strains were used: Saccharomyces cerevisiae sensitive to the glucose effect and Kluyveromyces fragilis insensitive to the catabolite respression when growing on lactose. The oxidative ATP generation rate followed by these two strains a Michaelis Menten kinetics against the dissolved oxygen concentration. Dissolved oxygen tension only influenced the glycolytic ATP generation rate in Kluyveromyces fragilis. Thus glucose and Pasteur effects are two mutually exclusive regulatory mechanisms of the energy yielding metabolism of the yeasts.