The Veillonellaceae are a family of the

Clostridia The Clostridia are a highly polyphyletic class of Bacillota, including ''Clostridium'' and other similar genera. They are distinguished from the Bacilli by lacking aerobic respiration. They are obligate anaerobes and oxygen is toxic to them. S ...

, formerly known as Acidaminococcaceae.

Bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

in this family are grouped together mainly based on genetic studies, which place them among the

Bacillota The Bacillota (synonym Firmicutes) are a phylum of bacteria, most of which have gram-positive cell wall structure. The renaming of phyla such as Firmicutes in 2021 remains controversial among microbiologists, many of whom continue to use the earl ...

. Supporting this placement, several species are capable of forming

endospore An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota. The name "endospore" is suggestive of a spore or seed-like form (''endo'' means 'within'), but it is not a true spore (i.e., no ...

s. However, they differ from most other Bacillota in having

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...

stains. The

cell wall A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mech ...

composition is peculiar. Members of this family are all obligate anaerobes, and occur in habitats such as rivers, lakes, and the intestines of vertebrates. They range from spherical forms, such as ''Megasphaera'' and ''

Veillonella ''Veillonella'' are Gram-negative bacteria (Gram stain pink) anaerobic cocci, unlike most Bacillota, which are Gram-positive bacteria. This bacterium is well known for its lactate fermenting abilities. It is a normal bacterium in the intestine ...

'', to curved rods, as typified by the

Selenomonad Members of the genus ''Selenomonas'' (motile crescent-shaped bacteria in general) are referred to trivially as selenomonads. The genus ''Selenomonas'' constitutes a group of motile crescent-shaped bacteria and includes species living in the gas ...

s. ''

Selenomonas Members of the genus ''Selenomonas'' (motile crescent-shaped bacteria in general) are referred to trivially as selenomonads. The genus ''Selenomonas'' constitutes a group of motile crescent-shaped bacteria and includes species living in the gast ...

'' has a characteristic crescent-shape, with flagella inserted on the concave side, while ''Sporomusa'' is similar but non-motile. Their names refer to this distinctive morphology: ''

selene In ancient Greek mythology and religion, Selene (; grc-gre, Σελήνη , meaning "Moon"''A Greek–English Lexicon's.v. σελήνη) is the goddess and the personification of the Moon. Also known as Mene, she is traditionally the daughter o ...

'' means moon, and ''musa'' means

banana A banana is an elongated, edible fruit – botanically a berry – produced by several kinds of large herbaceous flowering plants in the genus ''Musa''. In some countries, bananas used for cooking may be called "plantains", distinguis ...

. The name Selenobacteria also refers to some this group. The description of this family was emended in 2010 and, together with the ''

Acidaminococcaceae The Negativicutes are a class of bacteria in the phylum Bacillota, whose members have a peculiar cell wall with a lipopolysaccharide outer membrane which stains gram-negative, unlike most other members of the Bacillota. Although several neighbou ...

'' ( familia nova, which means a newly coined taxa), it was placed in the order ''

Selenomonadales The Selenomonadales are an order of bacteria within the class Negativicutes; unlike most other members of Bacillota, they are Gram-negative. The phylogeny of this order was initially determined by 16S rRNA comparisons. More recently, molecular ...

'' (ordo novus) in the class ''

Negativicutes The Negativicutes are a class of bacteria in the phylum Bacillota, whose members have a peculiar cell wall with a lipopolysaccharide outer membrane which stains gram-negative, unlike most other members of the Bacillota. Although several neighbour ...

'' (classis novus) of the phylum Bacillota.

Phylogeny

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 naming and taxonomy of prokaryotes, following the taxonomy requirements and rulings of the International Code of Nomenclature ...

(LPSN) and

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)

References

Clostridia Bacteria families {{bacteria-stub

Phylogeny

See also

References