Nitrobacter
Nitrobacter is a genus of mostly rod-shaped, gram-negative, and chemoautotrophic bacteria.
Nitrobacter plays an important role in the nitrogen cycle by oxidizing nitrite into nitrate in soil. 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 fixes carbon dioxide via the Calvin cycle for their carbon requirements.