Sulfurisphaera
In taxonomy, Sulfurisphaera is a genus of the Sulfolobaceae.
Sulfurisphaera is a facultatively anaerobic, thermophilic, Gram-negative archaeon that occurs in acidic solfataric fields. The organism grows under the temperature range of 63–92 °C with the optimum temperature at 84 °C, and under the pH range of 1.0–5.0, with an optimum of pH 2.0. It forms colonies that are smooth, roundly convex, and slightly yellow.