RANK: Genus

TAXONOMY: Bacteria -> Bacteroidetes/Chlorobi group -> Bacteroidetes -> Cytophagia -> Cytophagales -> Cytophagaceae -> Cytophaga


Moderately long flexible rods 0.3–0.5 µm wide and 2–10 µm long with slightly tapering ends. Motile by gliding. Nonspore-forming. Resting stages are absent. Gram-stain-negative. Aerobic, having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor. Chemo-organotrophic. Cell mass is yellow to orange owing to carotenoids, flexirubin-type pigments, or both. Oxidase-positive. Catalase-negative. Terrestrial organisms, common in soil. The optimum pH for growth is 7. Crystalline cellulose (filter paper) and carboxymethyl cellulose are degraded. The major respiratory quinone is MK-7. The major polyamine is homospermidine. DNA G+C content (mol%): 37–42. Type species: Cytophaga hutchinsonii