Structural and functional role of lipids in yeast and mycelial forms of Candida albicans.

The levels of total lipids, sterols and phospholipids were found to be significantly higher in the mycelial form (log phase) of Candida albicans than in the yeast form. Increased phospholipid levels in the mycelial form were due to higher levels of phosphatidylcholine, phosphatidylserine and phosphatidylinositol. Analyses of fatty acid composition also revealed higher levels of myristic acid (40%) in the yeast form, resulting in higher levels of saturated lipids than in the mycelial form. The changes in the lipid composition were also manifested in altered thermotropic phase behavior as gel-to-liquid crystalline phase transitions were observed at 36 and 27 degrees C for the lipids of the yeast and mycelial forms, respectively. These changes coincided with higher uptake rate, i.e., Km and Vmax values, for the transport of L-proline and with a higher sensitivity of the mycelial form against antifungal drugs.