Thermosphaera aggregans DSM 11486

Thermosphaera aggregans (strain DSM 11486 / M11TL) is a strictly anaerobic, hyperthermophile archaeum isolated from water and sediment samples of a terrestrial circumneutral hot solfataric spring ("Obsidian Pool") located in the Mud Volcano area of the Yellowstone National Park, Wyoming. It is restricted to hot, pH neutral, terrestrial springs. T. aggregans is a regular coccus that preferentially grows in grape-like aggregates consisting of five to several hundred individuals. It grows optimally at 85 degrees Celsius, and the temperature range for growth is 67 to 90 degrees Celsius. The pH range for growth is 5.0-7.0 with an optimum at pH 6.5. T. aggregans grows optimally in the absence of exogenous NaCl, but can be adapted to salt concentrations of up to 0.7%. Upon growth on yeast extract and peptone, the fermentation products acetate, isovalerate, CO(2) and H(2) are identified, but no growth on meat extract, amylose, glycogen, cellulose, cellobiose, maltose, raffinose, pyruvate and acetate is observed. Growth is inhibited by sulfur and H(2). Interestingly, an inhibiting effect in cultures of T. aggregans is not observed, if growth media are supplemented with the sulfur compounds sulfide, sulfite or thiosulfate, so that this effect seems to be restricted to elemental sulfur. The inhibiting effect of H(2) on growth is reversible and can be explained by a product inhibition of sensitive hydrogenases, which may be required for the disposal of reducing equivalents as hydrogen during fermentation. (Adapted from : http://standardsingenomics.org/index.php/sigen/article/view/sigs.821804/204). (HAMAP: THEAM)