Caldifarciminota

It is widely distributed in various environments, including hot springs, marine ecosystems, and hydrothermal vents, yet its ecological roles and metabolic capabilities remain poorly understood.

Nomenclature

Three candidate phylum names have been proposed for the WOR-3 lineage: the phylum "Candidatus Pyropristinus" was proposed for the MAG sequence of "Candidatus Caldipriscus" sp. T1.2 from the Bechler Spring microbial filament in Yellowstone National Park in 2016, the phylum "Candidatus Hydrothermae" was named after the representative MAG sequence of "Candidatus Hydrothermae pacifica" JdFR-72 retrieved from a Juan de Fuca Ridge flank subsurface fluid in 2017, and the phylum "Candidatus Stahlbacteria" was proposed for several MAG sequences belonging to the WOR-3 lineage in the absence of representatives in 2017.

According to the International Code of Nomenclature of Prokaryotes these three candidate phylum names were later corrected to "Candidatus Caldipriscota", "Candidatus Hydrothermota", and "Candidatus Stahliibacteriota".

The validly published name Caldifarciminota is based on the name of the species Caldifarcimen microaerophilum, a facultatively anaerobic, thermophilic, Gram-negative bacterium isolated from a deep-sea hydrothermal field in 2026.

Etymology: The Latin adjective caldus means hot, the Latin neutrum farcimen means a sausage.