Abstract
Qualitative and quantitative profiles of phospholipids, neutral lipids, and fatty acid composition in Cr. neoformans during the growth phase were investigated in relation to pyrophosphatidic acid. A marked increase of the total lipid content, which depended on the accumulation of triglyceride in yeast cells with the growth, was observed. The total phospholipid contents in yeast cells remained almostly constant during the exponential phase and slightly decreased in the stationary phase. The major phospholipids of this yeast were phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, and cardiolipin, the next groups being pyrophosphatidic acid, phosphatidic acid, lysophosphatidylcholine, and unidentified components. The amounts of phosphatidylcholine, phosphatidylinositol, and cardiolipin were fairly constant throughout the growth phase, but the amount of phosphatidylethanolamine increased and that of phosphatidylserine decreased with progressive growth. The pyrophosphatidic acid contents were 0.9_??_0.7% for total phospholipid during the growth phase. The major fatty acids of pyrophosphatidic acid were C16:0, C18:1, and C18:2 acids. The changing patterns of fatty acid composition in pyrophosphatidic acid through the growth phase closely resembled that of phosphatidic acid, which contained larger amounts of C18:1 acid (35_??_45%) than C16:0 acid (30_??_25%) and C18:2 acid (30_??_25%). Phosphatidylserine and phosphatidylinositol contained considerable amounts of saturated fatty acid (C16:0 acid, more than 55%). On the other hand, phosphatidylcholine, phosphatidylethanolamine, and cardiolipin contained extremely large amounts of unsaturated fatty acid (C18:1 and C18:2 acid, 85_??_90%).
