Extremophiles

, Volume 8, Issue 1, pp 53–61

Salt-induced changes in lipid composition and membrane fluidity of halophilic yeast-like melanized fungi

Authors

  • Martina Turk
    • Institute of Biochemistry, Medical FacultyUniversity of Ljubljana
    • Biology Department, Biotechnical FacultyUniversity of Ljubljana
  • Laurence Méjanelle
    • Department of Environmental ChemistryICER-CSIC
  • Marjeta Šentjurc
    • J. Stefan Institute
  • Joan O. Grimalt
    • Department of Environmental ChemistryICER-CSIC
  • Nina Gunde-Cimerman
    • Biology Department, Biotechnical FacultyUniversity of Ljubljana
    • Institute of Biochemistry, Medical FacultyUniversity of Ljubljana
Original Paper

DOI: 10.1007/s00792-003-0360-5

Cite this article as:
Turk, M., Méjanelle, L., Šentjurc, M. et al. Extremophiles (2004) 8: 53. doi:10.1007/s00792-003-0360-5

Abstract

The halophilic melanized yeast-like fungi Hortaea werneckii, Phaeotheca triangularis, and the halotolerant Aureobasidium pullulans, isolated from salterns as their natural environment, were grown at different NaCl concentrations and their membrane lipid composition and fluidity were examined. Among sterols, besides ergosterol, which was the predominant one, 23 additional sterols were identified. Their total content did not change consistently or significantly in response to raised NaCl concentrations in studied melanized fungi. The major phospholipid classes were phosphatidylcholine and phosphatidylethanolamine, followed by anionic phospholipids. The most abundant fatty acids in phospholipids contained C16 and C18 chain lengths with a high percentage of C18:2Δ9,12. Salt stress caused an increase in the fatty acid unsaturation in the halophilic H. werneckii and halotolerant A. pullulans but a slight decrease in halophilic P. triangularis. All the halophilic fungi maintained their sterol-to-phospholipid ratio at a significantly lower level than did the salt-sensitive Saccharomyces cerevisiae and halotolerant A. pullulans. Electron paramagnetic resonance (EPR) spectroscopy measurements showed that the membranes of all halophilic fungi were more fluid than those of the halotolerant A. pullulans and salt-sensitive S. cerevisiae, which is in good agreement with the lipid composition observed in this study.

Keywords

Aureobasidium pullulans Halophilic/halotolerant fungi Hortaea werneckii Lipid composition Membrane fluidity Phaeotheca triangularis Salt stress

Copyright information

© Springer-Verlag 2004