Thermosphaera

Thermosphaera
Scientific classification
Domain:	Archaea
Kingdom:	Crenarchaeota
Phylum:	Crenarchaeota
Class:	Thermoprotei
Order:	Desulfurococcales
Family:	Desulfurococcaceae
Genus:	Thermosphaera Huber, Dyba, Huber, Burggraf & Rachel, 1998
Species
T. aggregans

In taxonomy, Thermosphaera is a genus of the Desulfurococcaceae. They 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.

Cell structure and metabolism

Cells of Thermosphaera are cocci (spherical) and form grape-like aggregates during the exponential growth phase. In the late exponential 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.

Ecology

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.

Genome structure

Sequencing the 16S rRNA of Thermosphaera showed that this isolate was a member of the group Crenarchaeota and closely related to Staphylothermus and Desulfurococcus.

Further reading

Scientific journals

• Huber R; Dyba D; Huber H; Burggraf S; Rachel R (1998). "Sulfur-inhibited Thermosphaera aggregans sp. nov., a new genus of hyperthermophilic archaea isolated after its prediction from environmentally derived 16S rRNA sequences". Int. J. Syst. Bacteriol. 48: 31–38. doi:10.1099/00207713-48-1-31. PMID 9542073.
• Burggraf S; Huber H; Stetter KO (1997). "Reclassification of the crenarchael orders and families in accordance with 16S rRNA sequence data". Int. J. Syst. Bacteriol. 47 (3): 657–660. doi:10.1099/00207713-47-3-657. PMID 9226896.
• Huber R; Burggraf S; Mayer T; Barns SM; Rossnagel P; Stetter KO (1995). "Isolation of a hyperthermophilic archaeum predicted by in situ RNA analysis". Nature. 376 (6535): 57–58. doi:10.1038/376057a0. PMID 7541115.
• Zillig W; Stetter KO; Prangishvilli D; Schafer W; Wunderl S; Janekovic D; et al. (1982). "Desulfurococcaceae, the second family of the extremely thermophilic, anaerobic, sulfur-respiring Thermoproteales". Zentralbl. Bakteriol. Parasitenkd. Infektionskr. Hyg. Abt. 1 Orig. C3: 304–317.