title: Cultivation of a thermophilic ammonia oxidizing archaeon synthesizing crenarchaeol.
abstract: The widespread occurrence and diversity of ammonia oxidizing Archaea suggests their contribution to the nitrogen cycle is of global significance. Their distribution appeared limited to low- and moderate-temperature environments until the recent finding of a diagnostic membrane lipid, crenarchaeol, in terrestrial hot springs. We report here the cultivation of a thermophilic nitrifier ('Candidatus Nitrosocaldus yellowstonii'), an autotrophic crenarchaeote growing up to 74 degrees C by aerobic ammonia oxidation. The major core lipid of this archaeon growing at 72 degrees C is crenarchaeol, providing the first direct evidence for its synthesis by a thermophile. These findings greatly extend the upper temperature limit of nitrification and document that the capacity for ammonia oxidation is broadly distributed among the Crenarchaeota.
authors.affiliation: Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98195-2700, USA.
authors.forename: José R
authors.initials: JR
authors.lastname: de la Torre
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Walker
authors.forename: Anitra E
authors.initials: AE
authors.lastname: Ingalls
authors.forename: Martin
authors.initials: M
authors.lastname: Könneke
authors.forename: David A
authors.initials: DA
authors.lastname: Stahl
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D001105:Archaea / Q000378:metabolism*; D019615:Crenarchaeota / Q000235:genetics / Q000378:metabolism*; D005995:Glyceryl Ethers / Q000302:isolation & purification / Q000378:metabolism*; D045482:Hot Springs; D006358:Hot Temperature; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D013696:Temperature
chemical_list: D005995:Glyceryl Ethers; C493345:crenarchaeol; D000641:Ammonia