[Effect of quinocitrinines from the fungus Penicillium citrinum on the respiration of yeasts and bacteria].

We studied the effect of quinocitrinines on the respiratory activity of yeasts (Yarrowia lipolytica) and bacteria (Arthrobacter globiformis). Quinocitrinines were shown to activate respiration of native cells in both types of organisms. Studies of yeast mitochondria showed that quinocitrinine exerts an uncoupling effect on oxidative phosphorylation, which activates the respiration, reduces the respiratory control, and decreases the ADP/O ratio. Experiments with intact mitochondria and native cells of Arthrobacter globiformis revealed that quinocitrinine decreases the membrane potential. The uncoupling effect likely constitutes a mechanism of the antibiotic activity of quinocitrinines.