Some characteristics of nystatin-resistant sterol mutants of Candida albicans.

Various stable, auxotrophic and nystatin-resistant sterol mutants of Candida albicans were isolated after nitrosoguanidine treatment. Sterol mutants were divided into groups on the basis of the ultraviolet spectra and thin-layer chromatographic patterns of their nonsaponifiable sterol extracts. They were further characterized by their conductometrically measured nystatin-induced ion release. These sterol mutants displayed a decreased growth yield and an increased cell volume. On media containing 0.01% of the carbon sources, most of them could assimilate glycerol, alpha-methyl-D-glucoside, DL-lactic acid, L-sorbose, L-arabinose and ribitol only to a significantly reduced extent, or not at all. It is presumed that these properties result from the altered sterol composition of the plasma membrane.