Wirthbacteria

{{Short description|Proposed bacterial phylum}}

{{One source|date=April 2025}}

{{Use dmy dates|date=April 2025}}

{{Taxobox

|name = Wirthbacteria

|image =

|image_caption =

|domain = Bacteria

|unranked_phylum = CPR group

|phylum = "Wirthbacteria"

|phylum_authority = Hug et al. 2016

|genus = "Ca. Wirthibacter"

|genus_authority = Probst et al. 2017

|type_species = "Ca. Wirthibacter wanneri"

|type_species_authority = Probst et al. 2017

| subdivision_ranks = Species

| subdivision =

• "Ca. W. wanneri"

}}

Candidatus Wirthbacteria is a proposed bacterial phylum containing only one known sample from the Crystal Geyser aquifer, Ca. Wirthibacter wanneri. This bacterium stands out in a basal position in some trees of life as it is closely related to Candidate phyla radiation but is not considered part of that clade.{{cite journal |last1=Probst |first1=AJ |last2=Castelle |first2=CJ |last3=Singh |first3=A |last4=Brown |first4=CT |last5=Anantharaman |first5=K |last6=Sharon |first6=I |last7=Hug |first7=LA |last8=Burstein |first8=D |last9=Emerson |first9=JB |last10=Thomas |first10=BC |last11=Banfield |first11=JF |title=Genomic resolution of a cold subsurface aquifer community provides metabolic insights for novel microbes adapted to high CO₂ concentrations. |journal=Environmental Microbiology |date=February 2017 |volume=19 |issue=2 |pages=459–474 |doi=10.1111/1462-2920.13362 |pmid=27112493|osti=1567074 |s2cid=21126011 |url=https://escholarship.org/uc/item/400782gj }}