In the nitrogen cycle, which microorganism is responsible for the nitrification step?

In the nitrogen cycle, nitrification is a crucial process that involves the conversion of ammonia into nitrates, which plants can use as nutrients. The microorganisms that play a pivotal role in this step are Nitrosomonas and Nitrobacter.

Nitrosomonas is primarily responsible for the first part of nitrification, where it oxidizes ammonia (NH3) to nitrite (NO2-). Following this, Nitrobacter takes over the process by converting nitrites into nitrates (NO3-). This two-step process is essential for maintaining nitrogen availability in the soil and, consequently, supporting plant growth.

The other microorganisms listed in the choices are not involved in nitrification. For example, Escherichia coli is commonly found in the intestines of animals and humans and is important for digestion but does not play a role in the nitrogen cycle processes. Actinobacteria are important in soil health and organic matter degradation, but they do not specifically engage in nitrification. Clostridium botulinum is a pathogenic anaerobic bacterium known for producing botulinum toxin and does not participate in the nitrogen cycle.

Understanding the specific functions of different microorganisms helps clarify their roles in nutrient cycles, particularly the significance of Nitros