Their classification is based on the shape and flagellation. The type of growth and biochemical characteristics are important. Nitrobacter winogradskyi is facultatively mixotrophic and capable of growing anaerobically with nitrate as electron acceptor, producing nitrite, nitric oxide and nitrous oxide. Aerobically it oxidises nitric oxide to nitrite and thence to nitrate. It can use nitric oxide as a substrate for NADH production.
Heterotrophic growth is slow and inefficient.
All tricarboxylic acid cycle enzymes are present. There is no information. There are none known to be produced. They live together with the ammonia oxidisers. They are present in many soils, natural stones as well as fresh or brackish waters.