The importance of denitrification performed by nitrogen-fixing bacteria used as inoculants in South America

Background Replacing synthetic fertilizers by biological nitrogen fixation (BNF) is regarded as an environmentally sound practice, but some diazotrophic bacteria are capable of emitting N2O by denitrification. The ability to use nitrate represents an ecological advantage for the survival of some microorganisms under O2-limiting conditions, but may contribute to increased N2O emissions.