Nitrosomonas is a genus of Gram-negative bacteria belonging to the Betaproteobacteria class. As an obligate chemolithoautotroph, it uses ammonia (NH₃) as an energy source and carbon dioxide (CO₂) as a carbon source in the presence of oxygen. Here are some key points about Nitrosomonas:

1. Role in the Nitrogen Cycle:

   • Nitrosomonas plays a crucial role in the global biogeochemical nitrogen cycle.

   • It converts ammonia (NH₃) to nitrite (NO₂⁻) through a process called nitrification.

   • This conversion increases the bioavailability of nitrogen to plants