Unveiling the contribution of particle-associated non-cyanobacterial diazotrophs to N2 fixation in the upper mesopelagic North Pacific Gyre
Dinitrogen (N<sub>2</sub>) fixation supports marine life through the supply of reactive nitrogen. Recent studies suggest that particle-associated non-cyanobacterial diazotrophs (NCDs) could contribute significantly to N<sub>2</sub> fixation contrary to the paradigm of diazotrophy as primarily driven by cyanobacterial genera. We examine the community composition of NCDs associated with suspended, slow, and fast-sinking particles in the North Pacific Subtropical Gyre. Suspended and slow-sinking particles showed a higher abundance of cyanobacterial diazotrophs than fast-sinking particles, while fast-sinking particles showed a higher diversity of NCDs including Marinobacter, Oceanobacter and Pseudomonas. Using single-cell mass spectrometry we find that Gammaproteobacteria N<sub>2</sub> fixation rates were higher on suspended and slow-sinking particles (up to 67 ± 48.54 fmol N cell⁻¹ d⁻¹), while putative NCDs' rates were highest on fast-sinking particles (121 ± 22.02 fmol N cell⁻¹ d⁻¹). These rates are comparable to previous diazotrophic cyanobacteria observations, suggesting that particle-associated NCDs may be important contributors to pelagic N<sub>2</sub> fixation.
Authors
- Angelicque White (ORCID: https://orcid.org/0000-0002-0938-7948)
- Reece C. James
- Léo Berline (ORCID: https://orcid.org/0000-0002-5831-7399)
- Mar Benavides (ORCID: https://orcid.org/0000-0001-9502-108X)
- Tully Rohrer (ORCID: https://orcid.org/0000-0003-4720-0678)
- Kevin R. Arrigo (ORCID: https://orcid.org/0000-0002-7364-876X)
- Olivier Grosso (ORCID: https://orcid.org/0000-0002-6443-4006)
- Alba Filella (ORCID: https://orcid.org/0000-0001-9675-8884)
- Gert L. van Dijken (ORCID: https://orcid.org/0000-0002-9587-6317)
- Matthew M. Mills (ORCID: https://orcid.org/0000-0002-9738-5589)
- Kendra A. Turk‐Kubo (ORCID: https://orcid.org/0000-0002-9847-7514)
- Christian Furbo Reeder (ORCID: https://orcid.org/0000-0003-0866-3987)
- Anna V. Voznyuk
- Arthur Coët
Institutions
- University of Hawaiʻi at Mānoa (US)
- Centre National de la Recherche Scientifique (FR)
- University of Arizona (US)
- Université de Toulon (FR)
- University of California, Santa Cruz (US)
- National Oceanography Centre (GB)
- Aix-Marseille Université (FR)
- Linnaeus University (SE)
- Living Systems (United States) (US)
- Institut de Recherche pour le Développement (FR)
- Stanford University (US)
Publication Details
- Journal
- Communications Biology
- Published
- 2025-02-22
- DOI
- https://doi.org/10.1038/s42003-025-07542-w
- Citations
- 5
- Primary Topic
- Microbial Community Ecology and Physiology
- Type
- article
- Field-Weighted Citation Impact
- 8.58
Funders
- National Science Foundation
- Sight Research UK
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Natural Environment Research Council
- Division of Electrical, Communications and Cyber Systems