Fibrobacterota is a small
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...
l
phylum which includes many of the major
rumen
The rumen, also known as a paunch, is the largest stomach compartment in ruminants and the larger part of the reticulorumen, which is the first chamber in the alimentary canal of ruminant animals. The rumen's microbial favoring environment al ...
bacteria, allowing for the degradation of plant-based
cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell w ...
in
ruminant
Ruminants (suborder Ruminantia) are hoofed herbivorous grazing or browsing mammals that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microbial actions. The ...
animals. Members of this phylum were categorized in other phyla. The genus ''
Fibrobacter
Fibrobacterota is a small bacterial phylum which includes many of the major rumen bacteria, allowing for the degradation of plant-based cellulose in ruminant animals. Members of this phylum were categorized in other phyla. The genus '' Fibrobac ...
'' (the only genus of Fibrobacterota) was removed from the genus ''
Bacteroides
''Bacteroides'' is a genus of Gram-negative, obligate anaerobic bacteria. ''Bacteroides'' species are non endospore-forming bacilli, and may be either motile or nonmotile, depending on the species. The DNA base composition is 40–48% GC. Unus ...
'' in 1988.
Phylogeny and Comparative Genomic Studies
Although ''Fibrobacterota'', which consists of a single genus ''
Fibrobacter
Fibrobacterota is a small bacterial phylum which includes many of the major rumen bacteria, allowing for the degradation of plant-based cellulose in ruminant animals. Members of this phylum were categorized in other phyla. The genus '' Fibrobac ...
'' containing two species, is currently recognized as a distinct phylum, phylogenetic studies based RpoC and Gyrase B protein sequences, indicate that ''Fibrobacter succinogenes'' is closely related to the species from the phyla ''Bacteroidetes'' and ''Chlorobi''.
The species from these three phyla also branch in the same position based upon conserved signature indels in a number of important proteins. Lastly and most importantly, comparative genomic studies have identified two conserved signature indels (a 5-7 amino acid insert in the RpoC protein and a 13-16 amino acid insertion in
serine hydroxymethyltransferase
Serine hydroxymethyltransferase (SHMT) is a pyridoxal phosphate (PLP) (Vitamin B6) dependent enzyme () which plays an important role in cellular one-carbon pathways by catalyzing the reversible, simultaneous conversions of L-serine to glycine ...
) and one signature protein (PG00081) that are uniquely shared by all of the species from these three phyla.
All of these results provide compelling evidence that the species from these three phyla shared a common ancestor exclusive of all other bacteria and it has been proposed that they should all recognized as part of a single “FCB”superphylum.
Phylogeny
Phylogeny of Fibrobacterota.
Taxonomy
The currently accepted taxonomy is based on the
List of Prokaryotic names with Standing in Nomenclature
List of Prokaryotic names with Standing in Nomenclature (LPSN) is an online database that maintains information on the nomenclature, naming and Taxonomy (biology), taxonomy of prokaryotes, following the taxonomy requirements and rulings of the In ...
(LSPN) and the
National Center for Biotechnology Information
The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The ...
(NCBI).
* Class
Chitinispirillia Sorokin et al. 2016
** Order
Chitinispirillales Sorokin et al. 2016]
*** Family
Chitinispirillaceae Sorokin et al. 2016
**** Genus ''
Chitinispirillum''
Sorokin et al. 2016
***** Species ''
C. alkaliphilum''
Sorokin et al. 2016
* Class
Chitinivibrionia Sorokin et al. 2014
** Order
Chitinivibrionales Sorokin et al. 2014
*** Family
Chitinivibrionaceae Sorokin et al. 2014
**** Genus ''
Chitinivibrio''
Sorokin et al. 2014
***** Species ''
C. alkaliphilus''
Sorokin et al. 2014
* Class Fibrobacteria
Spain et al. 2012
** Order
Fibrobacterales Spain et al. 2012 Abdul_Rahman_et_al._2016.html" ;"title="Fibromonadales" Abdul Rahman et al. 2016">Fibromonadales" Abdul Rahman et al. 2016*** Family
Fibrobacteraceae Spain et al. 2012 Abdul_Rahman_et_al._2016.html" ;"title="ibromonadaceae" Abdul Rahman et al. 2016">ibromonadaceae" Abdul Rahman et al. 2016**** Genus "''
Hallerella''"
Wylensek et al. 2020
***** Species "''
H. porci''"
Wylensek et al. 2021
***** Species "''
H. succinigenes''"
Wylensek et al. 2020
**** Genus "''Candidatus''
Fibromonas"
Abdul Rahman et al. 2016
***** Species "''Ca.''
F. termitidis"
Abdul Rahman et al. 2016
**** Genus ''
Fibrobacter
Fibrobacterota is a small bacterial phylum which includes many of the major rumen bacteria, allowing for the degradation of plant-based cellulose in ruminant animals. Members of this phylum were categorized in other phyla. The genus '' Fibrobac ...
''
Montgomery et al. 1988
***** Species ''
F. intestinalis''
Montgomery et al. 1988
***** Species ''
F. succinogenes''
(Hungate 1950) Montgomery et al. 1988
****** Subspecies ''
F. s. elongatus''
Montgomery et al. 1988
****** Subspecies ''
F. s. succinogenes''
(Hungate 1950) Montgomery et al. 1988
Distribution
The phylum Fibrobacterota is considered to be closely related to the CFB
ytophaga-Flavibacterium-Bacteroidota The only genus in this phylum is ''Fibrobacter'' that contains strains from the guts of many mammals including cattle and pigs. The two described species in this genus namely, ''
Fibrobacter succinogenes'' and ''
Fibrobacter intestinalis'' are important members of fibrolytic communities in mammalian guts and have received a lot of attention in recent decades due to the long-standing interest microbes capable of degrading plant fiber.
Molecular evidence based on the amplification of 16rRNA genes from various environments suggest that the phylum is much more widespread than previously thought.
[
] Most of the clones from mammalian environments group along with the known isolates in what has been called subphylum 1.
Members of subphylum 2 however, have so far been found only in the gut of termites.
and in some litter-feeding cockroaches. The predominance of subphylum 2 in cellulolytic fibre-associated bacterial communities in hindguts of wood-feeding
Nasutitermes corniger
''Nasutitermes corniger'' is a species of arboreal termite that is endemic to the neotropics. It is very closely related to '' Nasutitermes ephratae''.
The species has been studied relatively intensively, particularly on Barro Colorado Island, Pa ...
suggests that they play an important role in the breakdown of plant material in higher termites.
See also
* ''
Fibrobacter succinogenes''
*
Candidate phylum TG3
*
List of bacterial orders
This article lists the orders of the Bacteria. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI)
and the phylogeny is based on 16S ...
*
List of bacteria genera This article lists the genera of the bacteria. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI). However many taxonomic names are ...
References
*
External links
* ''List of Prokaryotic Names with Standing in Nomenclature''
Genus ''Fibrobacter''* Systema Naturae 2000 Classification: Phylu
{{Taxonbar, from=Q1200941
Bacteria phyla