Insights into extreme thermoacidophily based on genome analysis of Picrophilus torridus and other thermoacidophilic archaea

Thermoacidophiles are prokaryotic microorganisms with the stunning capability to survive and multiply at extremely low pH and simultaneously at high temperatures. The mechanisms by which these organisms, exclusively members of the Archaea, cope with their harsh surroundings are poorly understood. The genome sequences of several representatives of the thermoacidophilic genera Picrophilus, Thermoplasma and Sulfolobus have recently become available. Genome-wide comparison has revealed a number of features as possible facets of the overall acidophilic survival strategy of the most thermoacidophilic organisms known, such as a high ratio of secondary over primary transport systems, the composition of the respiratory chain, and the frequent genetic input via lateral gene transfer (LGT) during evolution.