How do ammonia-oxidizing archaea influence the nitrogen cycle?

Ammonia-oxidizing archaea play a significant role in the nitrogen cycle by acting as primary converters of ammonia in various environments. While nitrification was traditionally attributed solely to specific groups of bacteria, research using culture-independent techniques has revealed that uncultivated organisms within the Crenarchaeota subdivision are among the most abundant ammonia-oxidizing organisms found in soils.1

Furthermore, these archaea are highly influential in marine ecosystems, accounting for a large proportion—roughly 20 percent—of the microorganisms present in the world's oceanic picoplankton. By oxidizing ammonia, these prokaryotic organisms contribute to the transformation of nitrogen compounds, a fundamental process that supports the availability of nutrients in global habitats.1