Picophytoplanktonic contribution to autotrophy in the field
Fouilland, E.; Descolas-Gros, C.; Courties, C.; Pons, V. (1998). Picophytoplanktonic contribution to autotrophy in the field, 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. 55-64 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
Aquatic communities > Plankton > Picoplankton
Nutritional types > Autotrophy
Marine/Coastal |
| Authors | | Top | - Fouilland, E.
- Descolas-Gros, C.
- Courties, C.
- Pons, V.
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| Abstract | The size-fractionated phytoplankton has different specific ecological properties in photosynthesis and nutrient uptake. Size-fractionated measurements of biomass and production have become an important mean to understand the structure and functioning of marine ecosystems. In the same way the study of these parameters at cellular scale is the necessary step to supply responses on physiological metabolisms. We focused on picoplankton fraction (< 2 µm), which in oligotrophic ocean systems accounts for up to 70 % of the inorganic carbon fixation and apparently have a high specific growth rates. This study presents the simultaneous measurements of different photosynthetic activities associated to size fractionation from Mediterranean sea and Antarctic Ocean with different environmental changes. The in vitro Rubisco (main Calvin-Benson enzyme) activity was measured simultaneously with cells number enumeration by flow cytometry (FCM), and with biomass (chlorophyll) measured by spectrofluorimetry. From these measurements the variations of photoautotrophic activity at cellular scale from picophytoplankton were studied. They allowed us to demonstrate that the picophytoplankton cells were able to adapt in short time their CO2 assimilation metabolisms in response to environmental changes (temperature, light regime, nutrient concentrations). |
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