Plasma membrane composition of Debaryomyces hansenii adapts to changes in pH and external salinity.
Debaryomyces hansenii is a marine yeast that has to cope with different stress situations. Since changes in membrane properties can play an important function in adaptation, we have examined the fluidity and lipid composition of purified plasma membranes of D. hansenii grown at different external pH values and salt concentrations. Growth at low pH caused an increase in the sterol-to-phospholipid ratio and a decrease in fatty acid unsaturation which was reflected in decreased fluidity of the plasma membrane. High levels of NaCl increased the sterol-to-phospholipid ratio and fatty acid unsaturation, but did not significantly affect fluidity. The sterol-to-phospholipid ratios obtained in D. hansenii grown under any of these conditions were similar to the ratios that have been reported for halophilic/halotolerant black yeasts, but much smaller than those observed in the model yeast Saccharomyces cerevisiae.
Turk
Martina
M
Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, Ljubljana, Slovenia.
Montiel
Vera
V
Department of Microbiology, ETSIAM, Edificio Severo Ochoa, Campus de Rabanales, University of Cordoba, Spain.
Žigon
Dušan
D
J. Stefan Institute, Jamova 39, Ljubljana, Slovenia.
Plemenitaš
Ana
A
Institute of Biochemistry, Medical Faculty, University of Ljubljana, Vrazov trg 2, Ljubljana, Slovenia.
Ramos
José
J
Department of Microbiology, ETSIAM, Edificio Severo Ochoa, Campus de Rabanales, University of Cordoba, Spain.
D002462:Cell Membrane / Q000737:chemistry* / Q000502:physiology; D005227:Fatty Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008560:Membrane Fluidity / Q000502:physiology; D010743:Phospholipids / Q000032:analysis; D004718:Saccharomycetales / Q000737:chemistry* / Q000187:drug effects / Q000502:physiology*; D054712:Salinity; D012965:Sodium Chloride / Q000737:chemistry; D013261:Sterols / Q000032:analysis
D005227:Fatty Acids; D010743:Phospholipids; D013261:Sterols; D012965:Sodium Chloride