Lipid composition of Rhodothermus marinus

The newly described thermophilic eubacterium Rhodothermus marinus was examined with respect to its lipid composition. The major respiratory lipoquinones present were MK-7, rather than MK-8 as found in members of the genus Thermus. The polar lipid composition also showed distinct differences, since only phospholipids were present, rather than the phospholipids and glycolipids typical of members of the genus Thermus. The fatty acids comprised straight chain unbranched as well as iso- and anteiso-branched fatty acids. These results show that members of the genera Thermus and Rhodothermus are not closely related.