Nitrospinota

Nitrospinota

The Nitrospinota is a phylum of bacteria that plays a crucial role in the nitrogen cycle, particularly in the oxidation of nitrite to nitrate, a process known as nitrite oxidation. This phylum is part of the larger group of bacteria involved in nitrification, which is essential for maintaining the balance of nitrogen in various ecosystems.

Taxonomy

The phylum Nitrospinota was previously classified under the class Nitrospirae, but recent phylogenetic studies have led to its reclassification as a distinct phylum. This reclassification is based on genetic and metabolic characteristics that distinguish Nitrospinota from other nitrifying bacteria.

Classes and Orders

The phylum Nitrospinota includes several classes and orders, with the most well-known being the class Nitrospinia. Within this class, the order Nitrospirales is the most studied, containing the genus *Nitrospina*.

Characteristics

Nitrospinota are Gram-negative bacteria that are typically found in marine environments, although they can also be present in freshwater and soil ecosystems. They are chemolithoautotrophs, meaning they obtain energy by oxidizing inorganic molecules, specifically nitrite, and use carbon dioxide as a carbon source.

Metabolism

The primary metabolic pathway of Nitrospinota involves the oxidation of nitrite (NO₂⁻) to nitrate (NO₃⁻). This process is a key step in the nitrogen cycle, facilitating the conversion of nitrogen compounds into forms that can be utilized by plants and other organisms.

Ecological Role

Nitrospinota contribute significantly to the nitrogen cycle, particularly in oceanic environments where they help regulate nitrogen availability. By converting nitrite to nitrate, they prevent the accumulation of nitrite, which can be toxic to marine life.

Genomics

The genome of Nitrospinota species reveals genes encoding for enzymes involved in nitrite oxidation, such as nitrite oxidoreductase. Genomic studies have also identified genes related to carbon fixation and energy conservation, highlighting their adaptability to various environmental conditions.

Research and Applications

Research on Nitrospinota is ongoing, with studies focusing on their role in biogeochemical cycles and potential applications in bioremediation. Understanding their metabolic pathways can lead to innovations in managing nitrogen pollution in aquatic systems.

Also see

• Nitrogen cycle
• Nitrification
• Nitrospira
• Chemolithoautotroph