Veillonellaceae

The Veillonellaceae are a family of the Clostridia, formerly known as Acidaminococcaceae. Bacteria in this family are grouped together mainly based on genetic studies, which place them among the Bacillota. Supporting this placement, several species are capable of forming endospores. However, they differ from most other Bacillota in having Gram-negative stains. The cell wall 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, to curved rods, as typified by the Selenomonads. Selenomonas 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 means moon, and musa means banana.