Nitrosomonas europaea cytochrome P460 is a direct link between nitrification and nitrous oxide emission.

ABSTRACT: Ammonia oxidizing bacteria (AOB) are major contributors to the emission of nitrous oxide (N₂O). It has been proposed that N₂O is produced by reduction of NO. Here, we report that the enzyme cytochrome (cyt) P460 from the AOB Nitrosomonas europaea converts hydroxylamine (NH₂OH) quantitatively to N₂O under anaerobic conditions. Previous literature reported that this enzyme oxidizes NH₂OH to nitrite ([Formula: see text]) under aerobic conditions. Although we observe [Formula: see text] formation under aerobic conditions, its concentration is not stoichiometric with the NH₂OH concentration. By contrast, under anaerobic conditions, the enzyme uses 4 oxidizing equivalents (eq) to convert 2 eq of NH₂OH to N₂O.

SUBMITTER: Caranto JD 

PROVIDER: S-EPMC5187719 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature