Urea-driven nitrification contributes to N2O production in the oligotrophic euphotic ocean.

ABSTRACT: Urea is an important alternative nitrogen source to ammonium for nitrification in oligotrophic oceans, yet its role in substrate-driven nitrous oxide (N2O) production remains poorly constrained. Here, we combined N2O isotopomer profiling, 15N-tracer incubations, and metagenomics to quantify and mechanistically resolve substrate-specific archaeal nitrification in the western tropical Pacific euphotic zone. Isotopomer-based mixing and fractionation model indicated that archaeal nitrification accounted for 69.6 ± 14.1% of microbial sources of N2O in oxygenated epipelagic waters. Depth-integrated urea-driven nitrification contributed 14-41% of total nitrification and 21-39% of nitrification-derived N2O, with contributions regulated by substrate proportions. Acidification experiments showed tha

SUBMITTER: Gu T 

PROVIDER: S-EPMC12774514 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature