Dive into the 2025 NY Wastewater Exam – Flush Away the Competition with Confidence!

The process of nitrification is a crucial part of the nitrogen cycle, which involves the conversion of ammonia to nitrate. In this specific stage of the nitrification cycle, nitrite is converted to nitrate by a specific group of bacteria.

The correct answer focuses on Nitrobacter, which is the bacteria responsible for this step. During nitrification, Nitrobacter oxidizes nitrite (NO2-) into nitrate (NO3-). This conversion is essential because it helps in removing toxic nitrite from the environment and transforming it into a form that can be utilized by plants.

Nitrosomonas, while related to the nitrification process, converts ammonia (NH3) into nitrite before Nitrobacter takes over. Other options like Aeromonas and Escherichia are not involved in the nitrification cycle: Aeromonas is generally associated with freshwater environments and can be pathogenic, while Escherichia, typically referring to Escherichia coli, is primarily known for its role in the digestive system and is not involved in nitrification. Understanding the specific roles of these bacteria in nitrogen conversion is essential for effective wastewater management and treatment processes.