A candidate division, candidate phylum or candidate division-level is a lineage of
prokaryotic
A prokaryote () is a single-celled organism that lacks a nucleus and other membrane-bound organelles. The word ''prokaryote'' comes from the Greek πρό (, 'before') and κάρυον (, 'nut' or 'kernel').Campbell, N. "Biology:Concepts & Connec ...
organisms for which until recently no
cultured representatives have been found, but evidence of the existence of the clade has been obtained by
16S rRNA 16S rRNA may refer to:
* 16S ribosomal RNA
16 S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome ( SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure.
The g ...
and
metagenomic analysis of environmental samples.
The term
candidatus
In prokaryote nomenclature, ''Candidatus'' (Latin for candidate of Roman office) is used to name prokaryotic phyla that are well characterized but yet-uncultured. Contemporary sequencing approaches, such as 16S sequencing or metagenomics, provide m ...
in fact means a species for which there is insufficient information to call it a new species according to the
International Code of Nomenclature of Bacteria
The International Code of Nomenclature of Prokaryotes (ICNP) formerly the International Code of Nomenclature of Bacteria (ICNB) or Bacteriological Code (BC) governs the scientific names for Bacteria and Archaea.P. H. A. Sneath, 2003. A short histor ...
Examples of Candidate division bacteria
*
Candidate division TM7
Saccharibacteria, formerly known as ''TM7'',
is a major bacterial lineage. It was discovered through 16S rRNA sequencing .
TM7x from the human oral cavity was cultivated and revealed that TM7x is an extremely small coccus (200-300 nm) a ...
(Saccharibacteria)
*
Poribacteria
Poribacteria are a candidate phylum of bacteria originally discovered in the microbiome of marine sponges (''Porifera''). Poribacteria are Gram-negative primarily aerobic mixotrophs with the ability for oxidative phosphorylation, glycolysis, ...
*
TG3 (candidate phylum) (Chitinivibrionia)
See also
*
Metagenomics
Metagenomics is the study of genetic material recovered directly from environmental or clinical samples by a method called sequencing. The broad field may also be referred to as environmental genomics, ecogenomics, community genomics or microb ...
*
Cloning
Cloning is the process of producing individual organisms with identical or virtually identical DNA, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction. In the field of biotechnology, c ...
*
DNA sequencing
References
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Candidatus taxa
Bacteria phyla
Archaea phyla