Minor contribution of ammonia oxidizers to inorganic carbon fixation in the ocean.

ABSTRACT: Ammonia-oxidizing archaea are the most abundant chemolithoautotrophs in the ocean and are assumed to dominate carbon fixation below the sunlit surface layer. However, the supply of reduced nitrogen delivered from the surface in sinking particulate organic matter is insufficient to support the amount of nitrification required to sustain measured carbon fixation rates in the dark ocean. Here we attempt to reconcile this observed discrepancy by quantifying the contribution of ammonia oxidizers to dark carbon fixation in the eastern tropical and subtropical Pacific Ocean. We used phenylacetylene-a specific inhibitor of the ammonia monooxygenase enzyme-to selectively inhibit ammonia oxidizers in samples collected throughout the water column (60-600 m depth). We show that, despite their high abu

SUBMITTER: Bayer B 

PROVIDER: S-EPMC12594613 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature