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Titel |
Nitrous Oxide (N2O) production in axenic Chlorella vulgaris microalgae cultures: evidence, putative pathways, and potential environmental impacts |
VerfasserIn |
B. Guieysse, M. Plouviez, M. Coilhac, L. Cazali |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 10, no. 10 ; Nr. 10, no. 10 (2013-10-25), S.6737-6746 |
Datensatznummer |
250085378
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Publikation (Nr.) |
copernicus.org/bg-10-6737-2013.pdf |
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Zusammenfassung |
Using antibiotic assays and genomic analysis, this study demonstrates nitrous
oxide (N2O) is generated from axenic Chlorella vulgaris
cultures. In batch assays, this production is magnified under conditions
favouring intracellular nitrite accumulation, but repressed when nitrate
reductase (NR) activity is inhibited. These observations suggest N2O
formation in C. vulgaris might proceed via NR-mediated nitrite
reduction into nitric oxide (NO) acting as N2O precursor via a pathway
similar to N2O formation in bacterial denitrifiers, although NO
reduction to N2O under oxia remains unproven in plant cells.
Alternatively, NR may reduce nitrite to nitroxyl (HNO), the latter being
known to dimerize to N2O under oxia. Regardless of the precursor
considered, an NR-mediated nitrite reduction pathway provides a unifying
explanation for correlations reported between N2O emissions from
algae-based ecosystems and NR activity, nitrate concentration, nitrite
concentration, and photosynthesis repression. Moreover, these results
indicate microalgae-mediated N2O formation might significantly
contribute to N2O emissions in algae-based ecosystems (e.g.
1.38–10.1 kg N2O-N ha−1 yr−1 in a 0.25 m deep raceway pond
operated under Mediterranean climatic conditions). These findings have
profound implications for the life cycle analysis of algae biotechnologies
and our understanding of the global biogeochemical nitrogen cycle. |
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