Pyrobaculum calidifontis JCM 11548

Pyrobaculum calidifontis (strain JCM 11548 / VA1) is a facultative anaerobic, hyperthermophilic archaeon phylogenetically associated with the kingdom Crenarchaeota. This strain was isolated from a water sample at the surface of a hot spring in the Philippines and grows under atmospheric air. Pyrobaculum calidifontis cannot use sulfur compounds for anaerobic growth. Oxygen serves as a final electron acceptor under aerobic culture conditions, whereas oxygen can be replaced by nitrate under anaerobic conditions. Therefore, studies on P. calidifontis should provide valuable information on how hyperthermophiles respond to, deal with, or utilize molecular oxygen. The sequencing of Pyrobaculum calidifontis will greatly assist in future microbiology investigations of the genus because it is able to grow both aerobically and anaerobically on simple organic media to high cell densities. Moreover, Pyrobaculum calidifontis can be plated under aerobic conditions. These characteristics will facilitate genetic, biochemical, and microbiological studies and encourage diverse investigators without requiring extensive experience with extremophiles. The comparative genomics of P. calidifontis and other Pyrobaculum species will be informative because some metabolic characteristics of P. calidifontis (ie growth under atmospheric O2 concentrations) are unique thus far among described members of the genus while other characteristics (ie sulfur toxicity) are shared with other species within the genus. (HAMAP: PYRCJ)