Nitrobacter

Nitrobacter is a genus comprising rod-shaped, gram-negative, and chemoautotrophic bacteria. The name Nitrobacter derives from the Latin neuter gender noun nitrum, nitri, alkalis; the Ancient Greek noun βακτηρία, βακτηρίᾱς, rod. They are non-motile and reproduce via budding or binary fission. Nitrobacter cells are obligate aerobes and have a doubling time of about 13 hours.

Nitrobacter play an important role in the nitrogen cycle by oxidizing nitrite into nitrate in soil and marine systems. Unlike plants, where electron transfer in photosynthesis provides the energy for carbon fixation, Nitrobacter uses energy from the oxidation of nitrite ions, NO₂⁻, into nitrate ions, NO₃⁻, to fulfill their energy needs. Nitrobacter fix carbon dioxide via the Calvin cycle for their carbon requirements. Nitrobacter belongs to the Alphaproteobacteria class of the Pseudomonadota.