ACTIVITY OF CERTAIN ENZYMES OF THE OXIDATIVE-METABOLISM OF A HEMOSTATE CULTURE OF THE YEAST CANDIDA-UTILIS AT VARIOUS LEVELS OF DISSOLVED-OXYGEN

The activity of cytochrome c oxidase (CO), cytochrome c peroxidase (CP), and catalase, as well as the content of cytochromes aa3, b, and c in the cytosolic fraction of a chemostat culture of Candida utilis VKM Y-1668, grown at various levels of dissolved oxygen, were determined. It was established that in the zone of the beginning of growth limitation by oxygen there is a sharp increase in the CO activity. An increased content of lactate in the cells was also noted here; the amount of cytochrome c and the CP activity increased simultaneously, and maximum catalase activity is exhibited. It can be assumed that all the enumerated changes in the cell metabolism are directed toward partial compensation for the deficiency of the major electron acceptor of the respiratory chain - oxygen.