Glacial meltwater and seasonality influence community composition of diazotrophs in Arctic coastal and open waters.
FEMS Microbiol Ecol
; 99(8)2023 07 21.
Article
en En
| MEDLINE
| ID: mdl-37349965
ABSTRACT
The Arctic Ocean is particularly affected by climate change with unknown consequences for primary productivity. Diazotrophs-prokaryotes capable of converting atmospheric nitrogen to ammonia-have been detected in the often nitrogen-limited Arctic Ocean but distribution and community composition dynamics are largely unknown. We performed amplicon sequencing of the diazotroph marker gene nifH from glacial rivers, coastal, and open ocean regions and identified regionally distinct Arctic communities. Proteobacterial diazotrophs dominated all seasons, epi- to mesopelagic depths and rivers to open waters and, surprisingly, Cyanobacteria were only sporadically identified in coastal and freshwaters. The upstream environment of glacial rivers influenced diazotroph diversity, and in marine samples putative anaerobic sulphate-reducers showed seasonal succession with highest prevalence in summer to polar night. Betaproteobacteria (Burkholderiales, Nitrosomonadales, and Rhodocyclales) were typically found in rivers and freshwater-influenced waters, and Delta- (Desulfuromonadales, Desulfobacterales, and Desulfovibrionales) and Gammaproteobacteria in marine waters. The identified community composition dynamics, likely driven by runoff, inorganic nutrients, particulate organic carbon, and seasonality, imply diazotrophy a phenotype of ecological relevance with expected responsiveness to ongoing climate change. Our study largely expands baseline knowledge of Arctic diazotrophs-a prerequisite to understand underpinning of nitrogen fixation-and supports nitrogen fixation as a contributor of new nitrogen in the rapidly changing Arctic Ocean.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Cianobacterias
/
Betaproteobacteria
Tipo de estudio:
Risk_factors_studies
Idioma:
En
Revista:
FEMS Microbiol Ecol
Año:
2023
Tipo del documento:
Article
País de afiliación:
Dinamarca