Qualitative and Quantitative Distribution of Diether Lipids in Haloalkaliphilic Archaebacteria

Abstract

The distribution of diether lipids in haloalkaliphilic archaebacteria was investigated by thin layer and gas chromatography. Using double development of silica gel thin layers it was possible to detect differences in the relative amounts of the previously described 2,3-di- O -phytanyl- sn -glycerol and 2- O -sesterterpanyl-3- O -phytanyl- sn -glycerol diethers. However, resolution of the diethers was not clear by this method, and a new method was developed using reverse phase thin layer chromatography for the separation of these diethers according to isopranyl chain length. The results obtained by this method allowed clear resolution of these two lipids and a third, 2,3-di- O -sesterterpanyl- sn -glycerol diether, further elucidating the results obtained by chromatography on silica gel thin layers. Quantitative determination of the distribution of the three diethers by gas chromatography showed that there was a wide variation in the relative amounts of these lipids. All strains examined were shown to contain the 2,3-di- O -phytanyl- sn -glycerol and 2-di- O -sesterterpanyl-3- O -phytanyl- sn -glycerol diethers. In some strains only traces of the latter diether were present, while in others it appeared to account for approximately 90 % of the diethers. Selection of a wide number of strains indicated that there was a complete spectrum of diether lipid distirubtion between these two extremes.