%0 Journal Article %A Lee, Jerry Y. %A Iglesias, Brenda %A Chu, Caleb E. %A Lawrence, Daniel J. P. %A Crane III, Edward Jerome %T Pyrobaculum igneiluti sp. nov., a novel anaerobic hyperthermophilic archaeon that reduces thiosulfate and ferric iron %D 2017 %J International Journal of Systematic and Evolutionary Microbiology, %V 67 %N 6 %P 1714-1719 %@ 1466-5034 %R https://doi.org/10.1099/ijsem.0.001850 %K mud volcano %K Pyrobaculum %K hyperthermophile %K Fe(III) respiration %K thiosulfate %I Microbiology Society, %X A novel anaerobic, hyperthermophilic archaeon was isolated from a mud volcano in the Salton Sea geothermal system in southern California, USA. The isolate, named strain 521T, grew optimally at 90 °C, at pH 5.5–7.3 and with 0–2.0 % (w/v) NaCl, with a generation time of 10 h under optimal conditions. Cells were rod-shaped and non-motile, ranging from 2 to 7 µm in length. Strain 521T grew only in the presence of thiosulfate and/or Fe(III) (ferrihydrite) as terminal electron acceptors under strictly anaerobic conditions, and preferred protein-rich compounds as energy sources, although the isolate was capable of chemolithoautotrophic growth. 16S rRNA gene sequence analysis places this isolate within the crenarchaeal genus Pyrobaculum . To our knowledge, this is the first Pyrobaculum strain to be isolated from an anaerobic mud volcano and to reduce only either thiosulfate or ferric iron. An in silico genome-to-genome distance calculator reported <25 % DNA–DNA hybridization between strain 521T and eight other Pyrobaculum species. Due to its genotypic and phenotypic differences, we conclude that strain 521T represents a novel species, for which the name Pyrobaculum igneiluti sp. nov. is proposed. The type strain is 521T (=DSM 103086T=ATCC TSD-56T). %U https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.001850