Deficient utilization of succinate in a sterol 14 alpha-demethylation mutant of Candida albicans.

Growth of a wild-type strain (KD14) started after a lag of approximately 15 h when glucose-grown cells of Candida albicans were incubated at 25 degrees C, with succinate as a sole energy/carbon source. No growth was observed, however, for a sterol 14 alpha-demethylation mutant (KD4900). During the lag period, the wild-type cells retained their respiratory activity, as measured with glucose as an added substrate, and developed the capacity to incorporate labelled succinate. In contrast, incubation with succinate for 15 h resulted in diminished respiratory activity and failed to induce the succinate uptake capacity of the mutant cells. These two differences from the wild-type seem to account for the inability of the mutant to grow in the presence of a non-fermentable substrate.