摘要：SummaryDenitrification supports anoxic growth ofPseudomonas aeruginosain infections. Moreover, denitrification may provide oxygen (O2) resulting from dismutation of the denitrification intermediate nitric oxide (NO) as seen inMethylomirabilis oxyfera. To examine the prevalence of NO dismutation we studied O2release byP. aeruginosain airtight vials.P. aeruginosarapidly depleted O2but NO supplementation generated peaks of O2at the onset of anoxia, and we demonstrate a direct role of NO in the O2release. However, we were not able to detect genetic evidence for putative NO dismutases.The supply of endogenous O2at the onset of anoxia could play an adaptive role whenP. aeruginosaenters anaerobiosis. Furthermore, O2generation by NO dismutation may be more widespread than indicated by the reports on the distribution of homologues genes. In general, NO dismutation may allow removal of nitrate by denitrification without release of the very potent greenhouse gas, nitrous oxide.Graphical abstractDisplay OmittedHighlights•Pseudomonas aeruginosawas found to release O2at the onset of anoxia•Peaks of O2were amplified in a nitric oxide reductase (NOR) mutant•The O2release was mediated by nitric oxide (NO)Biological sciences; Microbiology; Microbial physiology
