Higher order taxa:
Archaea, Crenarchaeota, Thermoprotei, Desulfurococcales, Desulfurococcaceae
Description and Significance
The Thermosphaera are a group of prokaryotic organisms which have been discovered in extremely hot environments such as sulfur springs, volcanoes, and magma pools. Isolates of thermosphaera were first identified in 1998 from the Obsidian Pool in Yellowstone National Park.
Sequencing the 16S rRNA of Thermosphaera showed that this isolate was a member of the group Crenarchaeota and closely related to Staphylothermus and Desulfurococcus.
Cell Structure and Metabolism
Cells of Thermosphaera are cocci (spherical) and form grape-like aggregates during the exponential growth phase. In the late logarithmic and stationary growth phases, smaller groups, including some single cells, were visible. Aggregates were shown to have several flagella; single cells could have as many as eight. The cell envelope is an amorphous layer covering a cytoplasmic membrane. Temperatures exceeding 92 C inhibits growth, as does sulfur and hydrogen. Thermosphaera cells are heterotrophic, processing energy from yeast.
Thermosphaera are found mainly in sulfaric pools, where they thrive on the extreme temperatures. In terms of research and economic significance, learning more about these organisms and their properties may help advancements in biotechnology.
Huber, R. et al. Sulfur-inhibited Thermosphaera aggregans sp. nov., a new genus of hyperthermophilic archaea isolated after its prediction from environmentally derived 16S rRNA sequences. International Journal of Systematic Biology vol 48 1998. (31-38)