Phytoplankton photorespiration and glycolate turnover in seawater
Leboulanger, C.; Descolas-Gros, C.; Jupin, H. (1998). Phytoplankton photorespiration and glycolate turnover in seawater, in: Dehairs, F.A. et al. (Ed.) Integrated Marine System Analysis. European Network for Integrated Marine System Analysis FWO Vlaanderen: Proceedings of the second network meeting (Brussels, May 29-31, 1997). pp. 111-119 In: Dehairs, F.A.; Elskens, M.; Goeyens, L. (Ed.) (1998). Integrated Marine System Analysis - European Network for Integrated Marine System Analysis FWO Vlaanderen: Proceedings of the second network meeting (Brussels, May 29-31, 1997). VUB. Laboratorium voor Analytische Chemie: Brussel. 376 pp., more |
| Keywords | Aquatic communities > Plankton > Phytoplankton
Respiration
Marine/Coastal |
| Authors | | Top | - Leboulanger, C.
- Descolas-Gros, C.
- Jupin, H.
| | |
| Abstract | Photosynthesis by fixing inorganic to organic carbon is the staple for most of the trophic chains. A biological reaction occurs simultaneously in microalgae, which causes organic carbon release (in the form of glycolate, a C2 molecule), called photorespiration. This contributes to wrong estimations of the net primary production (either as 14C incorporation or fluorescence measurements -Slooten 1996), and possibly enhances bacterial growth. In order to estimate the importance of photorespiratory losses in marine environment, two new methods were developed, allowing determination and quantification of dissolved glycolate in seawater. High performance liquid chromatography and gas chromatography were used after extraction and concentration of the compound. An improvement of qualitative determination was achieved by coup1ing to mass-spectrometry. By using both methods, we demonstrated a diel cyc1e for glycolate concentration in the euphotic layer of the ocean, with probable upper limitation by heterotrophic consumption. In oligotrophic waters, maximal glyco1ate amounts were linked to phytoplankton biomass. Finally, photorespiration and subsequent organic carbon release has to be taken into account to estimate more closely the extent of primary production, and when trophic relationships between planktonic organisms have to be finescale defined. Short lifespan compounds such as glycolate are likely to be linked to the biological carbon pump functioning. |
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