The polar lipid and fatty acid composition of Rhodothermus strains

The type strain of Rhodothermus marinus and five closely isolates from the Is. of S. Miguel, Azores, two halotolerant Thermus strains and one strain of Bacillus stearothermophilus were examined with respect to polar lipid and fatty acid composition. The polar lipids of all Rhodothermus strains were composed of five to seven phospholipids, three of which were identified as phosphatydilethanolamine, diphosphatydilglycerol and phosphatydilglycerol. One major phospholipid was not identified. Glycolipids were minor components. B. stearothemophilus also contained PE, PG and DPG, but the polar lipids of the Thermus strains were completely different. The fatty acid profiles of the Rhodothermus, Thermus and Bacillus strains were, on the other hand, very similar; branched-chain iso- and anteiso-fatty acids were the predominant acyl components of these organisms.