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Redox stratification within cryoconite granules influences the nitrogen cycle on glaciers
- Source :
- FEMS microbiology ecology. 96(11)
- Publication Year :
- 2020
-
Abstract
- Cryoconite granules are naturally occurring microbial structures on glacier surfaces worldwide. They play a key role in carbon and nitrogen cycling in glacier ecosystems and can accelerate the melting of snow and ice. However, detailed mechanism of nitrogen cycling in cryoconite granules remains unclear. Here, we demonstrate that redox stratification affects the spatial distribution of N cycling processes in cryoconite granules. Based on microsensor measurements for O2, NH4+, NO2– and NO3–, we identified the presence of fine-scale redox stratification within cryoconite granules. Cyanobacteria at the surface layer of the granules created oxic conditions, whereas the inner core of the granules was anoxic. Metatranscriptomic analyses indicated the active occurrences of nitrification in the inner core, whereas denitrification actively occurred both in the inner core and the surface layer of the granules. Cyanobacteria in the inner core of the granules were inactive, and likely dead and being degraded, providing carbon and nitrogen to support nitrifiers and denitrifiers. Quantities of nitrification genes/transcripts were greater in large cryoconite granules than small ones, most likely because nitrogen substrates were more abundantly present in the inner core of large granules due to distinct redox stratification. Our results suggest that the development of a granular structure of cryoconite granules can largely affect carbon and nitrogen cycling on glaciers.
- Subjects :
- 0301 basic medicine
Denitrification
010504 meteorology & atmospheric sciences
Nitrogen
chemistry.chemical_element
Biology
01 natural sciences
Applied Microbiology and Biotechnology
Microbiology
03 medical and health sciences
Cryoconite
Ice Cover
Psychrophile
Nitrogen cycle
Ecosystem
0105 earth and related environmental sciences
Ecology
Inner core
Nitrogen Cycle
Anoxic waters
Nitrification
030104 developmental biology
chemistry
Environmental chemistry
Oxidation-Reduction
Subjects
Details
- ISSN :
- 15746941
- Volume :
- 96
- Issue :
- 11
- Database :
- OpenAIRE
- Journal :
- FEMS microbiology ecology
- Accession number :
- edsair.doi.dedup.....1b4eda9163e8428837b55db1921bcd73