Genus XI. Simonsiella

Document Type



Organisms that exist in characteristic multicellular filaments that are flat rather than cylindrical and often segmented into groups of eight cells. The width of an individual cell is greater than its length. The long axis of an individual cell is perpendicular to the long axis of the filament. The diameter of the filaments (the width of the individual cells) may vary from about 2.0 to 8.0 um ,and the length of filaments may vary from about 10.0 to over 50.0 um. Individual cells within the filaments may be from about 0.5 to 1.3 um long. In thin sections cut perpendicular to the long axis of the filament, the cells are flattened and curved to yield a crescent-shaped, convex-concave (dorsal-ventral) asymmetry. The ends of the individual filaments are rounded. Gram negative. Gliding motility of the entire filament in the direction of the long axis when the flat side of the filament is in contact with a surface. Chemoorganotrophs. Aerobic. Some may produce acid aerobically from carbohydrates. Optimal temperature: 37°C. Found in the oral cavity of warm-blooded vertebrates.


Aerobic Bacteria; Physiology; Simonsiella


Bacteriology | Life Sciences | Microbial Physiology | Microbiology