title: Effect of temperature on the fatty acid composition of Thermus aquaticus.
abstract: Thermus aquaticus contains four major fatty acids, iso-C(15) (28%), iso-C(16) (9%), normal-C(16) (13%), and iso-C(17) (48%), when grown at 70 C, as determined by gas chromatography and mass spectrometry. Small amounts of iso-C(12), normal-C(12:1), iso-C(13), normal-C(14), iso-C(14), and normal-C(15:1) were also detected. A change in growth temperature (50 to 75 C at 5-C intervals) affects a shift in the proportions of some of the fatty acids. The proportions of the monoenoic and branched-C(17) fatty acids decreased and the proportions of the higher-melting iso-C(16) and normal-C(16) fatty acids increased. Cells grown at 75 C contained 70% more total fatty acids than cells grown at 50 C. The largest increases, in absolute amounts, were in the content of iso-C(16) and normal-C(16) fatty acids, with only a 1.6-fold increase in the major iso-C(15) and iso-C(17) fatty acids. There was a 2.5-fold decrease in normal-C(15:1) and at least a 24-fold decrease in anteiso-C(17), which is present at 50 and 55 C but not at higher temperatures. There was no difference in proportion or amount of fatty acids between exponential and stationary-phase cells grown at 70 C. When cells were grown on glutamate instead of yeast-extract and tryptone at 70 C, the total fatty acid content remained constant, but there was an increase in the proportions of iso-C(16) and normal-C(16) fatty acids concomitant with a decrease in the proportions of the iso-C(15) and iso-C(17) fatty acids.
mesh_terms: D001419:Bacteria / Q000032:analysis* / Q000254:growth & development / Q000378:metabolism; D002462:Cell Membrane / Q000032:analysis; D002849:Chromatography, Gas; D003124:Colorimetry; D003720:Densitometry; D005227:Fatty Acids / Q000032:analysis* / Q000378:metabolism; D005947:Glucose / Q000032:analysis; D008055:Lipids / Q000032:analysis; D010710:Phosphates / Q000032:analysis; D013053:Spectrophotometry; D013057:Spectrum Analysis; D013696:Temperature
chemical_list: D005227:Fatty Acids; D008055:Lipids; D010710:Phosphates; D005947:Glucose