bacteria genus - a genus of bacteria

order Pseudomonadales, Pseudomonadales - one of two usually recognized orders of true bacteria; gram-negative spiral or spherical or rod-shaped bacteria usually motile by polar flagella; some contain photosynthetic pigments

genus Nitrobacter, Nitrobacter - rod-shaped soil bacteria

genus Nitrosomonas, Nitrosomonas - ellipsoidal soil bacteria