title: Uncultivated thermophiles: current status and spotlight on 'Aigarchaeota'.
abstract: Meta-analysis of cultivation-independent sequence data shows that geothermal systems host an abundance of novel organisms, representing a vast unexplored phylogenetic and functional diversity among yet-uncultivated thermophiles. A number of thermophiles have recently been interrogated using metagenomic and/or single-cell genomic approaches, including members of taxonomic groups that inhabit both thermal and non-thermal environments, such as 'Acetothermia' (OP1) and 'Atribacteria' (OP9/JS1), as well as the exclusively thermophilic lineages 'Korarchaeota', 'Calescamantes' (EM19), 'Fervidibacteria' (OctSpA1-106), and 'Aigarchaeota' (HWCG-I). The 'Aigarchaeota', a sister lineage to the Thaumarchaeota, likely includes both hyperthermophiles and moderate thermophiles. They inhabit terrestrial, marine, and subsurface thermal environments and comprise at least nine genus-level lineages, several of which are globally distributed.
authors.affiliation: School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA; Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV 89154, USA. Electronic address: brian.hedlund@unlv.edu.
authors.forename: Brian P
authors.initials: BP
authors.lastname: Hedlund
authors.affiliation: School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA.
authors.forename: Senthil K
authors.initials: SK
authors.lastname: Murugapiran
authors.affiliation: School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA.
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Alba
authors.affiliation: DOE Joint Genome Institute, Walnut Creek, CA 94598, USA.
authors.forename: Asaf
authors.initials: A
authors.lastname: Levy
authors.affiliation: Department of Biology, California State University, San Bernardino, CA 92407, USA.
authors.forename: Jeremy A
authors.initials: JA
authors.lastname: Dodsworth
authors.affiliation: School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA.
authors.forename: Gisele B
authors.initials: GB
authors.lastname: Goertz
authors.affiliation: DOE Joint Genome Institute, Walnut Creek, CA 94598, USA.
authors.forename: Natalia
authors.initials: N
authors.lastname: Ivanova
authors.affiliation: DOE Joint Genome Institute, Walnut Creek, CA 94598, USA.
authors.forename: Tanja
authors.initials: T
authors.lastname: Woyke
mesh_terms: D001105:Archaea / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development; D044822:Biodiversity; D045482:Hot Springs / Q000382:microbiology*; D006358:Hot Temperature; D056186:Metagenomics; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S; D014871:Water Microbiology
chemical_list: D012336:RNA, Ribosomal, 16S