| My research provides this insight on the genus: Sulfolobus, a thermoacidophilic member of the kingdom, Crenarchaeota, within the domain of Archaea. Thermoacidophilic Sulfolobus acidocaldarius is an archaeon that can grow at pH 2–3 and high temperatures (65–85°C). Astoundingly, even under these extreme conditions, the intracellular pH of the thermoacidophilic archaea is neutral. In S. acidocaldarius membranes, 90% of the total lipids are bipolar tetraether lipids. The major component within the bipolar tetraether lipids is the polar lipid fraction E (PLFE). In order to study the properties of thermoacidophilic archaeal membranes, liposomes comprised of PLFE lipids were used to mimic intact in vivo membranes. My research focused on the water-membrane interfacial region, including the polar headgroup of PLFE. My overall dissertation research project goal was to investigate and elucidate the contributions of bipolar tetraether lipid membrane properties on thermoacidophilic archaea ability to thrive optimally in extreme acidic and high temperature habitats. The stability in corrosive environments has raised many questions as to which lipid properties (e.g. lipid headgroup interactions, lipid rigidity or lipid organization) confer this stability property. From my research, we know that there appears to be a conformational change within the water membrane interface of PLFE. This conformational change is dependent on temperature and may be influenced greatly by pH. Also, the high thermal stability and rigidity of PLFE were shown. (Abstract shortened by UMI.)... |
