Lipid component parts analysis of the hyperthermophilic sulfate-reducing archaeon Archaeoglobus fulgidus

Abstract

Archaeoglobus (A.) fulgidus is a hyperthermophilic, anaerobic, sulfate-reducing archaeon. Although the polar lipid composition of various archaea has been reported, no information has been available for A. fulgidus polar lipids. The present paper reports the results of lipid component parts analysis applied to the archaeon. Lipid component parts analysis is a simplified analytical method developed by the authors to obtain a rough outline of information about the polar lipid of a species of a microorganism. Unfractionated total lipid is subjected to several chemical degradation procedures to release lipid component parts (core lipids, glycolipid sugars and phospholipid polar head groups), which are identified by appropriate chromatography. Archaeol and caldarchaeol were found as core lipids along with an unknown core lipid. The major glycolipid sugars were galactose and mannose. A trace amount of glucose was also detected. The phosphodiester-linked polar head groups of phospholipids were inositol and ethanolamine. The presence of these lipid components is consistent with the occurrence of polar lipid-synthesizing enzymes detected by a BLAST search of the whole genome sequence of the organism. An amino group containing phospholipid was found for the first time in an archaeon other than methanogenic archaea.