solfataricus

Sulfolobus solfataricus is a thermoacidophilic archaeal species in the family Sulfolobaceae, order Sulfolobales. It inhabits acidic, sulfur-rich volcanic hot springs and solfataric vents. The epithet solfataricus refers to Solfatara, a volcanic crater near Naples, Italy, where the organism was first isolated. It is widely studied as a model archaeon for understanding life in extreme environments.

Physiology and metabolism: S. solfataricus thrives at high temperatures and low pH, with an optimum growth temperature around 80–85°C and a pH of about 2–3. It is typically aerobic and chemolithoautotrophic, oxidizing reduced sulfur compounds for energy while fixing carbon dioxide. The organism uses the 3-hydroxypropionate/4-hydroxybutyrate cycle for CO2 fixation, a pathway characteristic of many thermoacidophilic archaea. It can also exploit organic substrates under certain conditions. Morphologically, cells are irregular cocci or lobed shapes, often organized in cell aggregates.

Genomics and research significance: The genome of S. solfataricus is approximately 2.9 Mbp with around 3,000 predicted genes. It has been developed as a model organism for archaeal molecular biology, contributing to understanding of archaeal transcription, replication, and DNA repair. The organism harbors robust CRISPR-Cas systems that have informed studies of adaptive immunity in archaea. Its thermostable enzymes have practical applications in biotechnology and industry, contributing to the study of protein stability and function under extreme conditions.

Taxonomy and etymology: Domain Archaea; phylum Crenarchaeota; class Thermoprotei; order Sulfolobales; family Sulfolobaceae; genus Sulfolobus; species solfataricus. The name reflects its origin from Solfatara and its solfatarian habitat.