Tetraether-linked membrane monolayers in Ferroplasma spp: a key to survival in acid

• Published in: Extremophiles : life under extreme conditions Vol. 8; no. 5; pp. 411 - 419
• Main Authors: MACALADY, Jennifer L, VESTLING, Martha M, BAUMLER, David, BOEKELHEIDE, Nick, KASPAR, Charles W, BANFIELD, Jillian F
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01-10-2004; Tokyo Springer Nature B.V
• Subjects: Acids - metabolism; Archaea; Archaea - metabolism; Bacteriology; Biological and medical sciences; Chromatography, Thin Layer; Cytoplasm - metabolism; Desorption; Ferroplasma; Ferroplasma acidarmanus; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Ionization; Ions; Lipid Metabolism; Lipids; Lipids - chemistry; Magnetic Resonance Spectroscopy; Mass spectrometry; Microbiology; Miscellaneous; Sodium Chloride - chemistry; Space life sciences; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Temperature; Thermoplasmales - genetics; Thin layer chromatography; Time Factors; Drug combination; Gradient; Membrane monolayer; Tetraether lipid; Microbiology; Archaeobacteria; Archaea; Thermophily; NMR spectrometry; Matrix assisted laser desorption ionization; Thin layer chromatography; Acidophile; Bacteria; Acid mine drainage; Extreme environment
• DOI: 10.1007/s00792-004-0404-5
• EISSN: 1433-4909
• ISSN: 1431-0651

Ferroplasma acidarmanus thrives in hot, extremely low pH, metal-rich solutions associated with dissolving metal sulfide ore deposits. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and thin layer chromatography analyses of F. acidarmanus membranes indicate that tetraether lipids predominate, with at least three core lipid structures. NMR measurements indicate that the cytoplasmic pH of F. acidarmanus is approximately 5.6. The optimal growth pH is approximately 1.2, and the lowest growth pH is approximately 0.0. Thus, these organisms maintain pH gradients across their membranes that approach 5 pH units. Tetraether lipids were originally thought to be specifically associated with thermophiles but are now known to be widely distributed within the archaeal domain. Our data, in combination with recently published results for thermophilic and mesothermophilic acidophilic archaea, indicate that there may be a stronger association between tetraether lipids and tolerance to acid and/or large metal ion gradients.