FATTY-ACID COMPOSITION OF THE SPECIES OF THE GENERA THERMUS AND MEIOTHERMUS

In this study we examined the fatty acid composition of 63 strains of the genus Thermus and 25 strains of the genus Meiothermus. The major f atty acids of all of the organisms were iso- and anteiso-branched. Str aight chain fatty acids were, with some exceptions, present in small t o moderate amounts; monounsaturated fatty acids were only detected in M. ruber grown at low temperatures. All of the strains assigned to the species T. aquaticus and the type strain of T. filiformis contained m oderate proportions of 3-hydroxy fatty acids, but none of the other Th ermus strains contained these fatty acids. On the other hand, all of t he: strains of M. ruber, M. silvanus and M. chliarophilus contained mo derate amounts of 2-hydroxy fatty acids, although some strains also co ntained trace levels of 3-hydroxy fatty acids.