Aerobic denitrification in soils and sediments: From fallacies to factx.

Denitrification is the key step of the nitrogen cycle in which gaseous end products are released from the nitrate of terrestrial and aquatic environments. Although this process has always been regarded as an anaerobic one, recent research indicates that aerobic denitrification can be demonstrated with laboratory cultures and suggests that it may be widespread environmentally. Thus, denitrifying bacteria are both taxonomically and physiologically diverse, and may be predominantly aerobic. Simultaneous use of O(2) and NO(3)(-) as alternative terminal oxidants is not precluded in many bacteria, although the use of NO(3)(-) when O(2) is available is of no known advantage.