Nitrous oxide
Nitrous oxide is a 200-300 times more potent greenhouse gas than carbon dioxide, accounting for 5% of the global green house gas effect. During the reduction of nitrate in wastewater treatment, nitrous oxide is only released in the absence of appropriate oxygen regulation. Some solutions to combat the release of nitrous oxide from wastewater treatment could be to use aerobically denitrifying organisms with the capacity to fully reduce nitrogen. For instance, "P. denitrificans" has shown to efficiently reduce nitrate to N2 in cultured media and wastewater. Furthermore, TR2 strains of "P. sturzeri" and "Pseudomonas" sp. strain K50 were also shown to have substantially low levels of nitrous oxide production in water treatment. Thus enriching activated sludge for aerobic denitrifying bacteria can be effective in combating the global warming effects of nitrous oxide in wastewater treatment.