Conversion factor between acetylene reduction and nitrogen fixation in free-living cyanobacteria from high arctic habitats
| Autor: | Turid Liengen |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Cyanobacteria
Ethylene biology Anabaena Immunology chemistry.chemical_element General Medicine biology.organism_classification Applied Microbiology and Biotechnology Microbiology Nitrogen Nostoc commune chemistry.chemical_compound chemistry Acetylene Dry weight Environmental chemistry Botany Genetics Nitrogen fixation Molecular Biology |
| Zdroj: | Canadian Journal of Microbiology. 45:223-229 |
| ISSN: | 1480-3275 0008-4166 |
| DOI: | 10.1139/w98-219 |
| Popis: | The conversion factor between acetylene reduction and15N incorporation in free-living cyanobacteria was determined in different high arctic habitats in the area of Ny-Ålesund (78.5°N, 11.6°E), Spitsbergen, in the summer of 1994. The experiments were carried out under constant conditions, 19°C and 200 µE·m-2·s-1. The nitrogen-fixation activities, measured as15N-incorporation, were in the range 4.01-6.54 mg N2fixed·gdw-1·day-1(dw, dry weight) in sheets of Nostoc commune and 778-1206 mg N2fixed·m-2·day-1in the cyanobacterial crusts. The acetylene reduction activities were in the range 0.72-1.91 mg ethylene produced·gdw-1·day-1of N. commune and 12.8-63.7 mg ethylene produced·m-2·day-1in the cyanobacterial crusts. The conversion factor of N. commune ranged from 0.11 to 0.48 for ethylene produced to nitrogen fixed, whereas the cyanobacterial crusts covering the soil surface gave conversion factors in the range 0.022-0.073 for ethylene produced to nitrogen fixed. An Anabaena sp., isolated from one of the habitats investigated, gave conversion factors near the theoretical factor of 4, when determined at 14.0 and 17.3°C. It was concluded that the acetylene reduction activity of free-living cyanobacteria in high arctic habitats results in underestimates of the real nitrogen-fixation activity in these environments.Key words: nitrogen fixation, acetylene reduction, conversion factor, cyanobacteria, Nostoc commune, high arctic. |
| Databáze: | OpenAIRE |
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