Occurrence of fatty acids linked to non-phospholipid compounds in the polar fraction of a marine sedimentary extract from Carteau cove, France

A surface sediment from Carteau cove, located at the western part of the Gulf of Fos (France), was collected and analysed to determine the lipid composition of its most polar fraction. Analyses by high performance liquid chromatography (HPLC) and thin-layer chromatography (TLC) of the polar fraction of the sediment extract revealed the presence of phospholipids (PL), with mainly phosphatidylglycerol (PG), phosphatidylethanolamine (PE) and lysophosphatidylethanolamine (LPE), but also the presence of non-phospholipid polar compounds (NPC). Phospholipids and non-phospholipid polar compounds (NPC) were isolated by preparative thin-layer chromatography and trans-methylated. Phospholipid ester-linked fatty acids ranged from 12- to 20-carbon atoms and accounted for 34.8 mug(-1) of dry sediment whereas fatty acids derived from non-phospholipid polar compounds ranged from 12- to 28-carbon atoms and accounted for 39.1 mug g(-1) of dry sediment. The occurrence of significant amounts of fatty acids derived from non-phospholipid polar compounds of a sediment polar fraction illustrates the importance of the preliminary analysis and purification of phospholipids to avoid an overestimation of the microbial biomass when determined with a current phospholipid ester-linked fatty acids (PLFA) analysis. (C) 2001 Elsevier Science Ltd. All rights reserved.