Dark Diazotrophy during the Late Summer in Surface Waters of Chile Bay, West Antarctic Peninsula

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dc.contributor.authorAlcaman-Arias, Maria E.
dc.contributor.authorCifuentes-Anticevic, Jeronimo
dc.contributor.authorCastillo-Inaipil, Wilson
dc.contributor.authorFarias, Laura
dc.contributor.authorSanhueza, Cynthia
dc.contributor.authorFernandez-Gomez, Beatriz
dc.contributor.authorVerdugo, Josefa
dc.contributor.authorAbarzua, Leslie
dc.contributor.authorRidley, Christina
dc.contributor.authorTamayo-Leiva, Javier
dc.contributor.authorDiez, Beatriz
dc.date.accessioned2025-01-20T21:05:02Z
dc.date.available2025-01-20T21:05:02Z
dc.date.issued2022
dc.description.abstractAlthough crucial for the addition of new nitrogen in marine ecosystems, dinitrogen (N-2) fixation remains an understudied process, especially under dark conditions and in polar coastal areas, such as the West Antarctic Peninsula (WAP). New measurements of light and dark N-2 fixation rates in parallel with carbon (C) fixation rates, as well as analysis of the genetic marker nifH for diazotrophic organisms, were conducted during the late summer in the coastal waters of Chile Bay, South Shetland Islands, WAP. During six late summers (February 2013 to 2019), Chile Bay was characterized by high NO3- concentrations (similar to 20 mu M) and an NH4+ content that remained stable near 0.5 mu M. The N:P ratio was approximately 14.1, thus close to that of the Redfield ratio (16:1). The presence of Cluster I and Cluster III nifH gene sequences closely related to Alpha-, Delta- and, to a lesser extent, Gammaproteobacteria, suggests that chemosynthetic and heterotrophic bacteria are primarily responsible for N-2 fixation in the bay. Photosynthetic carbon assimilation ranged from 51.18 to 1471 nmol C L-1 d(-1), while dark chemosynthesis ranged from 9.24 to 805 nmol C L-1 d(-1). N2 fixation rates were higher under dark conditions (up to 45.40 nmol N L-1 d(-1)) than under light conditions (up to 7.70 nmol N L-1 d(-1)), possibly contributing more than 37% to new nitrogen-based production (>2.5 g N m(-2) y(-1)). Of all the environmental factors measured, only PO43--exhibited a significant correlation with C and N-2 rates, being negatively correlated (p < 0.05) with dark chemosynthesis and N-2 fixation under the light condition, revealing the importance of the N:P ratio for these processes in Chile Bay. This significant contribution of N-2 fixation expands the ubiquity and biological potential of these marine chemosynthetic diazotrophs. As such, this process should be considered along with the entire N cycle when further reviewing highly productive Antarctic coastal waters and the diazotrophic potential of the global marine ecosystem.
dc.fuente.origenWOS
dc.identifier.doi10.3390/microorganisms10061140
dc.identifier.eissn2076-2607
dc.identifier.urihttps://doi.org/10.3390/microorganisms10061140
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/93280
dc.identifier.wosidWOS:000818302800001
dc.issue.numero6
dc.language.isoen
dc.revistaMicroorganisms
dc.rightsacceso restringido
dc.subjectnitrogen fixation
dc.subjectheterotrophic diazotrophy
dc.subjectWAP/new production
dc.subjectdiazotrophy
dc.subject.ods14 Life Below Water
dc.subject.ods13 Climate Action
dc.subject.odspa14 Vida submarina
dc.subject.odspa13 Acción por el clima
dc.titleDark Diazotrophy during the Late Summer in Surface Waters of Chile Bay, West Antarctic Peninsula
dc.typeartículo
dc.volumen10
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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