Belahbib H. auteur aut IRD Summers Z. M. auteur aut IRD Fardeau Marie-Laure auteur aut IRD Joseph Manon auteur aut IRD Tamburini C. auteur aut IRD Dolla A. auteur aut IRD Ollivier Bernard auteur aut IRD Armougom Fabrice auteur aut IRD text journalArticle eng text/pdf reformatted digital access The phylum Thermotogae gathers thermophilic, hyperthermophic, mesophilic, and thermo-acidophilic anaerobic bacteria that are mostly originated from geothermally heated environments. The metabolic and phenotypic properties harbored by the Thermotogae species questions the evolutionary events driving the emergence of this early branch of the universal tree of life. Recent reshaping of the Thermotogae taxonomy has led to the description of a new genus, Pseudothermotoga, a sister group of the genus Thermotoga within the order Thermotogales. Comparative genomics of both Pseudothermotoga and Thermotoga spp., including 16S-rRNA-based phylogenetic, pan-genomic analysis as well as signature indel conservation, provided evidence that Thermotoga caldifontis and Thermotoga profunda species should be reclassified within the genus Pseudothermotoga and renamed as Pseudothermotoga caldifontis comb. nov. (type strain = AZM44c09(T)) and Pseudothermotogaprofunda comb. nov. (type strain =AZM34c06(T)), respectively. In addition, based upon whole-genome relatedness indices and DNA-DNA Hybridization results, the reclassification of Pseudothermotoga lettingae and Pseudothermotoga subterranea as latter heterotypic synonyms of Pseudothermotoga elfii is proposed. Finally, potential genetic elements resulting from the distinct evolutionary story of the Thermotoga and Pseudothermotoga clades are discussed. specialized Thermotogae Pseudothermotoga Taxonomy Classification 084 41 6 555-563 2018 0723-2020 https://www.documentation.ird.fr/hor/fdi:010074781 10.1016/j.syapm.2018.04.007 0723-2020 [F B010074781] https://www.documentation.ird.fr/hor/fdi:010074781 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers18-12/010074781.pdf IRD - Base Horizon / Pleins textes 2019-01-10 2023-07-11 fdi:010074781 fre