Figure 6: Polar membrane lipids of P. furiosus. Abbreviations used in the present study (see Table 1) to indicate phospholipids and glycolipids present in the membrane of P. furiosus always refer to diphytanylglycerol derived lipids. Two caldarchaeol lipids are shown: the main caldarchaeol (named hexose 2-PG-T) found in previous literature studies [20] and the structure proposed by us for the lipid component (named N-acetyl-hexose-hexose-P-Tcyclic) giving raise to the peak at m/z 1741.5 in MALDI-TOF/MS analysis.