Microbial basis for the biotechnological removal of nitrogen oxides from flue gases

This Review summarizes recent advances in the physiology and microbial biodiversity related to the removal of nitrogen oxides (NOx) from gaseous pollutants. A brief overview is given of recent chemical technologies and the biotechnological potential for removal of NOx from flue gases: microbiological processes related to NOx removal [aerobic denitrification, hydrogen-stimulated and thermophilic denitrification; anaerobic oxidation of ammonium (NH4+), combined nitrification-denitrification processes] metabolism of nitric oxide by denitrifiers and other micro-organisms; reaction of nitric oxide in higher temperature; combination of nitrogen and sulphur removal processes. This Review is addressed to biotechnologists, biochemists, microbiologists and physiologists.