A.ly.si.el' la. Gr. fem. n. alysion small chain; M.L. -ella dim. ending; M.L. fem. n. Alysiella small chain.

Proteobacteria / Betaproteobacteria / Neisseriales / Neisseriaceae / Alysiella

Organisms that exist in characteristic flat, ribbon-like multicellular filaments. The long axis of the individual cells is perpendicular to the long axis of the filament. The cells within the filament are paired, and in axenic culture the filament often breaks up into groups of two or four cells. The width of an individual cell (the width of a filament) is about 2.0–3.0 µm, and the length of a cell is about 0.6 µm. The length of the filament is quite variable. The filament does not show either a dorsal-ventral differentiation or a convex-concave curvature in transverse cross-section. The ends of the individual filaments are square. Gram negative. Motile by gliding of the entire filament in the direction of the long axis. Aerobic. Chemoorganotrophic. Some may produce acid aerobically from carbohydrates. Optimal temperature: 37°C. Found in the oral cavity of warm-blooded vertebrates

The mol % G + C of the DNA is: 44–48.

Type species: Alysiella filiformis (Schmid in Simons 1922) Langeron 1923, 118, Simonsiella filiformis Schmid in Simons 1922, 509.)