Bacteroidota
Gram-negative bacteria essential to gut health and global ecosystems.
Bacteroidota (synonym Bacteroidetes) is a phylum of Gram-negative, nonsporeforming, anaerobic or aerobic, rod-shaped bacteria widely distributed in the environment, including soil, sediments, sea water, and the guts and skin of animals. They are highly abundant in the gastrointestinal tract, performing essential metabolic conversions such as degradation of proteins and complex sugar polymers, and are among the most stable components of the gut microflora.
- phylum
- Bacteroidota
- type
- Gram-negative, nonsporeforming, rod-shaped bacteria
- habitat
- Soil, sediments, sea water, animal guts, skin
- first_isolated_species
- Bacteroides fragilis (1898)
- key_genera
- Bacteroides, Porphyromonas, Prevotella, Salinibacter
- metabolic_products
- Succinic acid, acetic acid, propionic acid
Quick Facts
- Taxon
- Bacteroidota
- Subdivision
- Bacteroidia / Krieg 2012 · Chitinophagia / Munoz et al. 2017 · Cytophagia / Nakagawa 2012 · Flavobacteriia / Bernardet 2012 · Saprospiria / Hahnke et al. 2018 · Sphingobacteriia / Kämpfer 2012
Facts from the source article.
Lore & Background
The phylum Bacteroidota comprises three large classes, with the class Bacteroidia being the most well-studied. Originally described as 'Bacillus fragilis' in 1898, the species later formally named Bacteroides fragilis was among the first Bacteroidota linked to human disease, notably appendicitis. For a long time, most Gram-negative gastrointestinal bacteria were thought to belong to the genus Bacteroides, but recent reclassification placed the majority of gastrointestinal Bacteroidota species into families Bacteroidaceae, Prevotellaceae, Rikenellaceae, and Porphyromonadaceae.
Reader's Guide
Bacteroidota are significant for their dual roles as both symbiotic gut bacteria and occasional opportunistic pathogens. In the gastrointestinal tract, they are essential for breaking down complex polysaccharides and proteins, producing short-chain fatty acids like succinic and acetic acid. Their abundance is linked to host health; reduced levels are associated with obesity, and they may be involved in type 1 and type 2 diabetes pathogenesis. Beyond the gut, Bacteroidota are abundant in soil, freshwater, and marine environments, including hypersaline lakes where the genus Salinibacter thrives. Comparative genomics has identified 27 proteins and a three-amino-acid deletion in the ClpB chaperone as molecular markers for the phylum. The phylum is closely related to Chlorobiota and Fibrobacterota, with evidence supporting a common ancestor exclusive of other bacteria, forming the FCB superphylum.
Did You Know?
- Originally described as 'Bacillus fragilis' in 1898, the species later formally named Bacteroides fragilis was among the first Bacteroidota linked to human disease, notably appendicitis.
- Bacteroidota can reach up to 10^11 cells per gram of intestinal material.
- The halophilic genus Salinibacter shares many properties with halophilic Archaea such as Halobacterium.
Frequently Asked Questions
Who is Bacteroidota?
Bacteroidota is a phylum of rod-shaped, Gram-negative bacteria that do not form spores and can grow either with or without oxygen. It is one of the most abundant bacterial lineages in animal intestines, though it is also widespread in soil, sediments, and seawater.
What are Bacteroidota's powers/role?
These bacteria specialize in degrading tough proteins and complex sugar polymers that many other organisms simply cannot break down. Their metabolic output includes succinic, acetic, and propionic acids, making them indispensable chemical workhorses in their ecosystems.
Where does Bacteroidota live?
Bacteroidota occupies a remarkably broad range of habitats, stretching from deep marine sediments and terrestrial soils to the gut tracts and skin surfaces of animals. Within the gastrointestinal tract it is among the most stable and persistent members of the microflora.
Why is Bacteroidota important?
Because it performs essential metabolic conversions in the gut, Bacteroidota is a cornerstone of digestive health and overall microbiome stability. Outside the body, members of this phylum also contribute to nutrient cycling in soil and marine environments, linking them to global biogeochemical processes.
What are Bacteroidota's key allies (genera)?
The most well-known genera within the phylum are Bacteroides, Porphyromonas, Prevotella, and Salinibacter. The very first species described from this group was Bacteroides fragilis, isolated in 1898.
More in Higher-Level Taxonomy & Evolution 1-24
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