A growing interest in bacterial ether lipids

Fatty acyl ester lipids constitute major membrane components of eukaryotic and most prokaryotic cell membranes. In contrast, studies on the lipids of a variety of anaerobic eubacteria and of archaebacteria, many of which are extreme halophiles, thermoacidophiles, and methanogens, have lead to the realization that ether lipids are major components of most of these organsms 1–4. The presence of ether lipids in organisms which live in environments similar to the Earth's earlier biosphere suggests that they may represent ancient lines of descent and that they are evolutionary relics. Increasingly the evidence appears to point toward specific roles in membrane organization and stability.