Nitrobacter is a genus of bacteria that plays a crucial role in the nitrogen cycle, specifically in the process of nitrification. These bacteria convert nitrites, which are toxic to plants, into nitrates, a form of nitrogen that plants can readily absorb and use for growth. Found in soil and aquatic environments, Nitrobacter thrives in oxygen-rich conditions. This process not only helps in maintaining soil fertility but also contributes to the overall health of ecosystems by ensuring that nitrogen is available in a usable form for various organisms, including plants and animals.