Characterization of cerulenin-resistant mutants of Candida albicans

Cerulenin, an inhibitor of fatty acid biosynthesis, has been used to study the role of the plasma membrane in germination of Candida albicans. To further elucidate this association, spontaneous, cerulenin-resistant mutants of C. albicans were isolated. Two of the mutants, 4918-2 and 4918-10, were compared biochemically with wild-type cells (4918). All strains grew equally well at 37 degrees C and synthesized fatty acids at comparable rates in the absence of the drug. In the presence of cerulenin, wild-type cells did not proceed through a logarithmic growth stage and exhibited a significantly impaired ability to incorporate [3H]acetate into newly synthesized lipid material. All strains were examined ultrastructurally. Alterations were observed in the membranous structures of cerulenin-treated wild-type cells. Such changes were not observed in cerulenin-treated mutant strains. Further examination of mutant strains revealed differences in cell wall protein and polysaccharide compositions when compared with those of wild-type cells. These apparent alterations in cell surface components may be correlated with the reduced abilities of mutant strains to adhere, in vitro, to mammalian cells.