Nitrobacteraceae

Nitrobacteraceae is a family of bacteria within the order Rhizobiales. This family is known for its role in the nitrogen cycle, specifically in the process of nitrification, where ammonia is converted into nitrite and then into nitrate.

Taxonomy

The family Nitrobacteraceae consists of two genera: Nitrobacter and Nitrococcus. These genera are differentiated by their cell shape and their preferred habitat. Nitrobacter cells are rod-shaped and are typically found in soil and freshwater environments, while Nitrococcus cells are spherical and are usually found in marine environments.

Metabolism

Members of the Nitrobacteraceae family are chemolithoautotrophs, meaning they derive energy from inorganic compounds and carbon from carbon dioxide. They are known as nitrifying bacteria because they oxidize nitrite (NO2-) to nitrate (NO3-) in the second step of nitrification. This process is crucial for the nitrogen cycle as it helps to convert nitrogen from a form that is unusable by most plants (ammonia) into a form that can be easily taken up (nitrate).

Ecological Significance

The Nitrobacteraceae family plays a significant role in the ecosystem. Their ability to convert nitrite to nitrate helps to maintain the balance of nitrogen in the soil, which is essential for plant growth. They also contribute to the removal of harmful ammonia from wastewater in wastewater treatment plants.

Health Implications

While Nitrobacteraceae are not typically pathogenic, they can cause problems in aquaculture systems. High levels of nitrate, the end product of nitrification, can be toxic to fish and other aquatic organisms. Therefore, managing the levels of Nitrobacteraceae and other nitrifying bacteria is crucial in these systems.

See Also

• Nitrogen cycle
• Nitrification
• Chemolithoautotrophs
• Rhizobiales