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Insight Horizon Media

What is the anammox reaction?

Author

John Castro

Published Mar 21, 2026

What is the anammox reaction?

Anammox (anaerobic ammonium oxidation), which is a reaction that oxidizes ammonium to dinitrogen gas using nitrite as the electron acceptor under anoxic conditions, was an important discovery in the nitrogen cycle.

What is anammox an abbreviation for what does it mean?

Anammox stands for Anaerobic Ammonium Oxidation. The process was discovered in the early nineties and has great potential for the removal of ammonia nitrogen in wastewater. The responsible bacteria transform ammonium (NH4+) and nitrogen dioxide (NO2) into nitrogen gas (N2) and water (H2O).

What is denitrification anammox?

Anammox and denitrification mediated by bacteria are known to be the major microbial processes converting fixed N to N2 gas in various ecosystems. Codenitrification and denitrification by fungi are additional pathways producing N2 in soils. Denitrifying bacteria were found to be the most abundant, followed by F.

What are the electron donor and acceptor in the anammox process?

Anammox bacteria convert ammonium (NH4+) to dinitrogen gas (N2) using intracellular electron acceptors such as nitrite (NO2−) or nitric oxide (NO).

Where does anammox reaction occur?

The anammox process was originally found to occur only from 20 °C to 43 °C but more recently, anammox has been observed at temperatures from 36 °C to 52 °C in hot springs and 60 °C to 85 °C at hydrothermal vents located along the Mid-Atlantic Ridge.

What reaction is catalyzed by anammox?

NeHAO is a key enzyme in aerobic ammonium-oxidizing bacteria, which catalyzes the four-electron oxidation of hydroxylamine to nitrite (Reaction 4), whereas KsHOX is a dominant protein in the anammox bacterium catalyzing the three-electron oxidation of hydroxylamine to NO (Reaction 5).

Where does anammox occur?

Is anammox aerobic?

The anaerobic ammonium oxidation (Anammox) process is a promising novel option for removing nitrogen from wastewater. Furthermore, aerobic nitrifiers were shown not to play an important role in the Anammox process.

What is the anammox reaction and where does it occur?

Anammox, an abbreviation for anaerobic ammonium oxidation, is a globally important microbial process of the nitrogen cycle that takes place in many natural environments. The bacteria mediating this process were identified in 1999, and were a great surprise for the scientific community.

How do you write the formula for ammonium ion?

NH₄⁺
Ammonium/Formula

How is the ammonium ion?

ions (cations), such as the ammonium ion (NH4+), which can be derived by the addition of a proton to a molecular base, in this case ammonia (NH3). The hydronium ion (H3O+), which is the hydrogen ion in aqueous solution, also belongs to this class.