Abstract
Cells of Sulfolobus acidocaldarius contain about 2.5% total lipid on a dry-weight basis. Total lipid was found to contain 10.5% neutral lipid, 67.6% glycolipid, and 21.7% polar lipid. The lipids contained C(40)H(80) isopranol glycerol diethers. Almost no fatty acids were present. The glycolipids were composed of about equal amounts of the glycerol diether analogue of glucosyl galactosyl diglyceride and a glucosyl polyol glycerol diether. The latter compound contained an unidentified polyol attached by an ether bond to the glycerol diether. The polar lipids contained a small amount of sulfolipid, which appeared to be the monosulfate derivative of glucosyl polyol glycerol diether. About 40% of the lipid phosphorus was found in the diether analogue of phosphatidyl inositol. The remaining lipid phosphorus was accounted for by approximately equal amounts of two inositol monophosphate-containing phosphoglycolipids, inositolphosphoryl glucosyl galactosyl glycerol diether and inositolphosphoryl glucosyl polyol glycerol diether.