Fibrobacterota is a smallbacterialphylum which includes many of the majorrumen bacteria, allowing for the degradation of plant-basedcellulose inruminant animals. Members of this phylum were categorized in other phyla. The genusFibrobacter was removed from the genusBacteroides in 1988.[2]
AlthoughFibrobacterota is currently recognized as a distinct phylum, phylogenetic studies based RpoC and Gyrase B protein sequences, indicate thatFibrobacter succinogenes is closely related to the species from the phylaBacteroidetes andChlorobi.[3] The species from these three phyla also branch in the same position based upon conserved signature indels in a number of important proteins.[4] 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 inserine hydroxymethyltransferase) and one signature protein (PG00081) that are uniquely shared by all of the species from these three phyla.[5] 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.[3][5]
The phylum Fibrobacterota is considered to be closely related to the CFB [Cytophaga-Flavibacterium-Bacteroidota].[5] It contains the genusFibrobacter, which has strains present in the guts of many mammals including cattle and pigs.[14] The two described species in this genus namely,Fibrobacter succinogenes andFibrobacter 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.[15][16] Most of the clones from mammalian environments group along with the known isolates in what has been called subphylum 1.[16] Members of subphylum 2 however, have so far been found only in the gut of termites.[16][17] and in some litter-feeding cockroaches.[18] The predominance of subphylum 2 in cellulolytic fibre-associated bacterial communities in hindguts of wood-feedingNasutitermes corniger suggests that they play an important role in the breakdown of plant material in higher termites.[19]
^abGupta, R. S. (2004). "The phylogeny and signature sequences characteristics of Fibrobacteres, Chlorobi, and Bacteroidetes".Critical Reviews in Microbiology.30 (2):123–140.doi:10.1080/10408410490435133.PMID15239383.S2CID24565648.
^McDonald, JE; Lockhart, RJ; Cox, MJ; Allison, HE; McCarthy, AJ (2008). "Detection of novelFibrobacter populations in landfill sites and determination of their relative abundance via quantitative PCR".Environmental Microbiology.10 (5):1310–1319.doi:10.1111/j.1462-2920.2007.01544.x.PMID18266756.
^Mikaelyan, A.; Dietrich, C.; Köhler, T.; Poulsen, M.; Sillam-Dussès, D.; Brune, A. (2015). "Diet is the primary determinant of bacterial community structure in the guts of higher termites".Molecular Ecology.24 (20):5824–5895.doi:10.1111/mec.13376.PMID26348261.S2CID206182668.
^Mikaelyan, A.; Köhler, T.; Lampert, N.; Rohland, J.; Boga, H.; Meuser, K.; Brune, A. (2015). "Classifying the bacterial gut microbiota of termites and cockroaches: A curated phylogenetic reference database (DictDb)".Systematic and Applied Microbiology.38 (7):472–482.doi:10.1016/j.syapm.2015.07.004.PMID26283320.
^Mikaelyan, A.; Strassert, J.; Tokuda, G.; Brune, A. (2014). "The fibre-associated cellulolytic bacterial community in the hindgut of wood-feeding higher termites (Nasutitermes spp.)".Environmental Microbiology.16 (9):2711–2722.doi:10.1111/1462-2920.12425.
Holt JG, ed. (1994).Bergey's Manual of Determinative Bacteriology (9th ed.). Williams & Wilkins.ISBN978-0-683-00603-2.
