TAXONOMY: Bacteria -> Terrabacteria group -> Firmicutes -> Clostridia -> Clostridiales -> Lachnospiraceae -> Oribacterium
Elongated ovoid rods, about 1.7–2.2 µm × 0.8–1.0 µm, usually occurring singly or in pairs and occasionally in short chains. Motile with laterally inserted flagella. Gram-stain-positive but may stain Gram-negative. Strictly anaerobic. Does not form spores. Catalase is not produced. Weakly fermentative. Abundant gas is produced in glucose broth cultures; nitrate reduction is negative; indole production is positive. Major metabolic end products in trypticase-glucose-yeast extract (TGY, see below) broth are acetic and lactic acids. Habitat: mouth, upper respiratory tract.
DNA G + C content (mol%): 42.4.
Type species: Oribacterium sinus
This genus contains microbial species that can reside in the human gastrointestinal tract. [PMC 4262072]