Nitrite (NO 2 − ) is a key denitrification intermediate, formed from nitrate (NO 3 − ). Transient NO 2 − accumulation varies among denitrifiers, yet the underlying causes remain poorly understood, despite its potential toxicity and role in NO and N 2 O emissions. We profiled 18 related Stutzerimonas strains, including the model Stutzerimonas perfectomarina ZoBell, and identified three phenotypic clusters (full, partial and low...

Summary Bacterial denitrification is a respiratory process that is a major source and sink of the potent greenhouse gas nitrous oxide. Many denitrifying bacteria can adjust to life in both oxic and anoxic environments through differential expression of their respiromes in response to environmental signals such as oxygen, nitrate and nitric oxide. We used steady‐state oxic and anoxic chemostat cultures to demonstrate that the s...

Summary Denitrifying bacteria convert nitrate (NO 3 ‐ ) to dinitrogen (N 2 ) gas through an anaerobic respiratory process in which the potent greenhouse gas nitrous oxide (N 2 O) is a free intermediate. These bacteria can be grouped into classes that synthesize a nitrite (NO 2 ‐ ) reductase (Nir) that is solely dependent on haem‐iron as a cofactor (e.g. Paracoccus denitrificans ) or a Nir that is solely dependent on copper (Cu...