[Effect of endogenous respiration of Candida mycoderma on the operation of the cytochrome system and the oxidation of glucose, ethanol and acids of the Krebs cycle]

Abstract

The kinetics of oxidation of glucose, ethanol, and acids of the Krebs cycle was studied in resting cells of Candida mycoderma which differed by the level of endogenous respiration (ER). The cells with ER close to zero oxidized glucose and ethanol almost at once and at a high rate. During oxidation of succinic or other acids of the Krebs cycle, QO2 was maximal only after a long period of adaptation (tad); a latent period (tlat) was observed sometimes during which assimilation of oxygen was either insignificant or not detected at all. The values of tad and tlat were much lower in the cells with high ER or upon preliminary introduction of small amounts of easily oxidized substrates (e. g. glucose or ethanol). During oxidation of succinate (citrate, malate or alpha-ketoglutarate) by the cells with ER close to zero, reduction of cytochrome c takes place only some time after the beginning of oxygen uptake. Such a delay suggests that oxidation of aforementioned substrates is initiated by some other electron carriers rather than by the cytochrome system.