Nomuraibacteriota

"Candidatus Nomuraibacteriota"
Scientific classification Edit this classification
(Candidatus)
Domain: Bacteria
Kingdom: incertae sedis
Informal group: Candidate phyla radiation
Phylum: "Candidatus Nomuraibacteriota"
corrig. Brown et al. 2015
Synonyms

"Candidatus Nomurabacteria" Brown et al. 2015

"Candidatus Nomuraibacteriota" is a candidatus phylum of bacteria belonging to the CPR group. They are ultra-small bacteria that have been found in a wide variety of environments, mainly in sediments under anaerobic conditions.

Bacteria of this phylum share several of their characteristics with other ultra-small bacteria, nanometric size, small genomes, reduced metabolism, and low capacity to synthesize nucleotides and aminoacids. They also lack respiratory chains and the Krebs cycle. In addition, many can be endosymbionts of larger bacteria.

Phylogenetic analyzes have suggested that Nomuraibacteriota and the other ultra-small bacteria make up the most basal clade of all bacteria. The archaea of the Nanobdellati kingdom are ultra-small archaea that share the same characteristics with these bacteria and are the most basal group of the archaeo-eukaryotic clade, although it can also be paraphyletic of eukaryotes and the other archaea as will be seen below.

In some phylogenetic analyzes of the proteome, ultra-small bacteria emerge outside the traditional bacterial domain and instead emerge as a paraphyletic group of traditional Bacteria and the clade composed of archaea and eukaryotes. In these analyzes Nomuraibacteriota turns out to be the most basal clade of all cellular organisms.

Phylogeny

Proteome analyzes have shown that Nomuraibacteriota can be the most basal clade of cellular organisms and that the other CPR bacteria are a paraphyletic group as can be seen in the cladogram that shows the phylogenetic relationships between multiple bacterial, archaean and eukaryotes.

A 2016 metagenomic representation of the tree of life using ribosomal protein sequences

References

  1. ↑ "Candidatus Nomuraibacteriota" in LPSN; Freese, H. M.; Meier-Kolthoff, J. P.; Sardà Carbasse, J.; Afolayan, A. O.; Göker, M. (2026). "TYGS and LPSN in 2025: a Global Core Biodata Resource for genome-based classification and nomenclature of prokaryotes within DSMZ Digital Diversity". Nucleic Acids Research. 54 (D1): D884–D891. doi:10.1093/nar/gkaf1110.
  2. 1 2 Castelle, C., Brown, C., Thomas, B. et al. Unusual respiratory capacity and nitrogen metabolism in a Parcubacterium (OD1) of the Candidate Phyla Radiation. Sci Rep 7, 40101 (2017) doi:10.1038/srep40101
  3. 1 2 3 4 5 Hug, L. A. et al. 2016, A new view of the tree of life. Nature Microbiology, 1, 16048.
  4. 1 2 3 Rijja Hussain Bokhari, Nooreen Amirjan, Hyeonsoo Jeong, Kyung Mo Kim, Gustavo Caetano-Anollés, Arshan Nasir (2020). Bacterial Origin and Reductive Evolution of the CPR Group. Oxford Academic. https://doi.org/10.1093/gbe/evaa024