Membrane fluidity in Bacillus subtilis. Validity of homeoviscous adaptation.
The validity of the principle of homeoviscous adaptation for Bacillus subtilis was tested by comparing fluorescence anisotropy (1,6-diphenyl-1,3,5-hexatriene) and electron-spin resonance (16-doxylstearate) measurements carried out in isolated plasma membranes and in phospholipid fractions. The physical measurements were supplemented by fatty-acid analysis. The results support our previous findings on intact cells. The thermoadaptive mechanism of B. subtilis manifested as an increase in relative proportion of branched anteiso-C15 and anteiso-C17 fatty acids, are not strong enough to compensate for the marked physical change of membrane fluidity induced by temperature decrease.
Svobodová
J
J
Department of Microbiology, Faculty of Science, Charles University, Prague.
Julák
J
J
Pilar
J
J
Svoboda
P
P
D000222:Adaptation, Physiological; D001412:Bacillus subtilis / Q000032:analysis / Q000502:physiology*; D004578:Electron Spin Resonance Spectroscopy; D005227:Fatty Acids / Q000032:analysis; D005454:Fluorescence Polarization; D008560:Membrane Fluidity; D010743:Phospholipids / Q000032:analysis
D005227:Fatty Acids; D010743:Phospholipids