Planktonic Aggregates as Hotspots for Heterotrophic Diazotrophy: The Plot Thickens

0557610 - MBÚ 2023 RIV CH eng J - Článek v odborném periodiku
Riemann, L. - Rahav, E. - Passow, U. - Grossart, H. - de Beer, D. - Klawonn, I. - Eichner, Meri - Benavides, M. - Bar-Zeev, E.
Planktonic Aggregates as Hotspots for Heterotrophic Diazotrophy: The Plot Thickens.
Frontiers in Microbiology. Roč. 13, APR 6 2022 (2022), č. článku 875050. ISSN 1664-302X. E-ISSN 1664-302X
Institucionální podpora: RVO:61388971
Klíčová slova: nitrogen-fixation * n-2 fixation * dinitrogen fixation * microbial-degradation * bacterial-growth * organic-carbon * marine * sinking * particles * cyanobacteria * aggregates * nitrogen fixation * heterotrophic bacteria * marine * aquatic * NCDs
Obor OECD: Microbiology
Impakt faktor: 5.2, rok: 2022
Způsob publikování: Open access
https://www.frontiersin.org/articles/10.3389/fmicb.2022.875050/full

Biological dinitrogen (N-2) fixation is performed solely by specialized bacteria and archaea termed diazotrophs, introducing new reactive nitrogen into aquatic environments. Conventionally, phototrophic cyanobacteria are considered the major diazotrophs in aquatic environments. However, accumulating evidence indicates that diverse non-cyanobacterial diazotrophs (NCDs) inhabit a wide range of aquatic ecosystems, including temperate and polar latitudes, coastal environments and the deep ocean. NCDs are thus suspected to impact global nitrogen cycling decisively, yet their ecological and quantitative importance remain unknown. Here we review recent molecular and biogeochemical evidence demonstrating that pelagic NCDs inhabit and thrive especially on aggregates in diverse aquatic ecosystems. Aggregates are characterized by reduced-oxygen microzones, high C:N ratio (above Redfield) and high availability of labile carbon as compared to the ambient water. We argue that planktonic aggregates are important loci for energetically-expensive N-2 fixation by NCDs and propose a conceptual framework for aggregate-associated N-2 fixation. Future studies on aggregate-associated diazotrophy, using novel methodological approaches, are encouraged to address the ecological relevance of NCDs for nitrogen cycling in aquatic environments.
Trvalý link: http://hdl.handle.net/11104/0331579