RT Journal Article SR Electronic T1 Candidatus Nitrosopolaris, a genus of putative ammonia-oxidizing archaea with a polar/alpine distribution JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.12.10.472193 DO 10.1101/2021.12.10.472193 A1 Igor S. Pessi A1 Aino Rutanen A1 Jenni Hultman YR 2022 UL http://biorxiv.org/content/early/2022/05/16/2021.12.10.472193.abstract AB Ammonia-oxidizing archaea (AOA) are key players in the nitrogen cycle of polar soils. Here, we analysed metagenomic data from tundra soils in Rásttigáisá, Norway, and recovered four metagenome-assembled genomes (MAGs) assigned to the genus “UBA10452”, an uncultured lineage of putative AOA in the order Nitrososphaerales (“terrestrial group I.1b”), phylum Thaumarchaeota. Analysis of other eight previously reported MAGs and publicly available amplicon sequencing data revealed that the UBA10452 lineage is predominantly found in acidic polar and alpine soils. In particular, UBA10452 MAGs were more abundant in highly oligotrophic environments such as mineral permafrost than in more nutrient-rich, vegetated tundra soils. UBA10452 MAGs harbour multiple copies of genes related to cold tolerance, particularly genes involved in DNA replication and repair. Based on the phylogenetic, biogeographical, and ecological characteristics of 12 UBA10452 MAGs, which include a high-quality MAG (90.8% complete, 3.9% redundant) with a nearly complete 16S rRNA gene, we propose a novel Candidatus genus, Ca. Nitrosopolaris, with four species representing clear biogeographical/habitat clusters.Competing Interest StatementThe authors have declared no competing interest.