The Effect of Growth Temperature on the Lipids in an Extremely Thermoacidophilic Bacterium, TA-1

Abstract

The extreme thermoacidophile TA-1, a Sulfolobus-like organism, was grown at temperatures ranging from 50 to 85°C (at 5°C intervals). The extracted cellular lipids were analysed qualitatively and quantitatively. At temperatures close to the optimum for growth, the levels of glycolipids in total lipid fractions increased. The phospholipid contents were constant except at extremely unfavorable tempertaures for the growth.

The alkyl-chains of the total lipid were analysed as alkyl-halide derivatives by gas-liquid chromatography. Usually seven to eight peaks were detected on the chromatogram. By increasing the growth temperature, the areas of peaks which had longer retention periods increased, but those of the shorter ones decreased. These results suggest that the extreme thermoacidophile TA-1 has some mechanisms which alter the membrane properties by changing lipid compositions and their alkyl-chains.