Final answer:
Denitrifying bacteria produce nitrogen gas (N2) by converting nitrates (NO3) back into atmospheric nitrogen during the denitrification process.
Step-by-step explanation:
Denitrifying bacteria are essential participants in the nitrogen cycle, performing the critical function of converting nitrates (NO3) back into nitrogen gas (N2) through a process known as denitrification. This microbial activity is crucial for maintaining the overall nitrogen balance in the environment.
During denitrification, denitrifying bacteria use nitrates as a terminal electron acceptor in their metabolic processes. As a result, nitrates are reduced to nitrogen gas, which is then released into the atmosphere. This step is vital for preventing the continuous accumulation of nitrates in the soil. If nitrification were the sole process, nitrates would accumulate over time, rendering nitrogen less accessible to organisms that require gaseous nitrogen for various biological processes.
Denitrification contributes to the sustainability of the nitrogen cycle, ensuring the availability of nitrogen in different forms for the diverse organisms that participate in this intricate biogeochemical cycle.