Thermosphaera

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A Microbial Biorealm page on the genus Thermosphaera

Thermosphaera aggregans. Image from International Journal of Systematic Bacteriology (1998).

Classification

Higher order taxa:

Archaea, Crenarchaeota, Thermoprotei, Desulfurococcales, Desulfurococcaceae

Species:

Thermosphaera aggregans

NCBI: Taxonomy Genome

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.

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.

Cell Structure and Metabolism

Cell surface and cytoplasm of a Thermosphaera cell. International Journal of Systematic Bacteriology (1998).

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.

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.

Obsidian's Pool in Yellowstone National Park, a habitat typical of Thermosphaera. Image from James W. Brown, North Carolina State University.

References

Huber, Harold et al. Hyperthermophiles and their possible potential in biotechnology. Review Article. Journal of Biotechnology vol 64 1998. (39-52)

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)

Marteinsson, Viggo Thor et al. Phylogenetic Diversity Analysis of Subterranean Hot Springs in Iceland. Applied and Enviornmental Microbiology vol 67(9) September 2001. (4242-4248)

Stetter, Karl O. Hyperthermophilic Microorganisms. Institute of Aerospace Medicine, Köln-Porz, Germany.

Vieille, Claire et al. Hyperthermophilic Enzymes: Sources, Uses, and Molecular Mechanisms for Thermostability. Microbiology and Molecular Biology Reviews vol 65(1) March 2001. (1-43)