Bacterial Denitrification: Asset or Defect?

Certain bacteria substitute nitrate for O2 in a form of anaerobic respiration called denitrification. Nitrite and N2O are confirmed intermediates; NO may be too, and N2 is the final product. Specific reductases catalyze each step after electrons pass the cytochrome b level. Much plant nutrient nitrogen is lost to denitrification, but unknown benefits may also result.