The membrane lipids of the marine ciliated protozoan Parauronema acutum

The membrane lipid composition of the marine ciliated protozoan Parauronema acutum was characterized. Phospholipids of P. acurum comprised 75% of the total lipids and consisted of phosphatidyl ethanolamine (33%), phosphatidyl choline and its phosphono analog (24%), phosphatidyl inositol (12%), phosphatidyl serine (8R), an unidentified phosphonolipid (18%) and small amounts of sphingomyelin, phosphatidic acid and lysophospholipid. Neutral sphingolipids comprised 15% of the total ciliate lipids and consisted of two major glycosphingolipids and six minor glycosphingolipids. These contained two kinds of long chain bases, one of which was sphingosine and either glucose or galactose or mixtures of both. The fatty acids of the total lipids of P. acutum consisted primarily of palmitic acid (13%), oleic acid (6%), linoleic acid (25%), α-linolenic aid (12%) plus highly unsaturated fatty acids of the ω-3 family including all-cis 6,9,12,15-octatetraenoic acid (9%), all-cis 5,8,11,14,17-eicosapentaenoic acid (10%) and all-cis 4,7,10,13,16,19,22-docosa-hexaenoic acid (9%). Individual lipids had their own specific fatty acid patterns.