Most denitrifying bacteria are heterotrophs, using organic carbon compounds as a source of energy.
Bacteria capable of carrying out denitrification are widely distributed among world soils. Denitrification is important in soil ecosystems for several reasons. First, removal of inorganic N by denitrification can influence the productivity of plants, since their growth is frequently limited by N. Second, denitrification is important to water quality. Nitrate is a federally listed drinking water pollutant and is an agent of eutrophication in marine ecosystems. Denitrification in soils, wetlands, streams and groundwater can prevent movement of NO 3 - from intensive upland land uses into aquatic ecosystems.