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| Nef, Charlotte; Henry, Céline; Nicolau, Elodie; Bérard, Jean-baptiste; Hervé, Fabienne; Caruana, Amandine; Kaas, Raymond; Mairet, Francis; Garnier, Matthieu. |
| Cobalamin (vitamin B12) is a cobalt-containing enzymatic cofactor involved in methionine synthesis. Provided only by select bacteria and archaea in marine systems, this vitamin is known to limit primary production in different oceanic areas. Understanding the consequences of cobalamin limitation on phytoplankton physiology is of great interest, notably for cobalamin-dependent haptophytes that significantly contribute to oceanic carbon fixation and sulfur cycle through dimethyl sulfonio propionate (DMSP) synthesis. Here, the effect of cobalamin limitation was compared to nitrogen limitation on the model haptophyte Tisochrysis lutea grown in chemostats, combining comparative proteomics with the analysis of major macromolecules and specific osmolytes. Our... |
| Tipo: Text |
Palavras-chave: Cobalamin; Vitamin B-12; Haptophyte microalgae; Tisochrysis lutea; DMSP; Chemostat; Comparative proteomics; Metabolism. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00654/76575/77711.pdf |
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| Corn, M; Belviso, S; Nival, P; Vigot, A; Buatmenard, P. |
| We report results from free-drifting sediment trap deployments at 200 m depth which enable measurement of the diel variations in the downward flux of detrital particulate dimethylsulphoniopropionate (DMSPp) over periods of 24-72 hours in three contrasting trophic regimes of the tropical northeastern Atlantic Ocean off Mauritania. The source of DMSPp was the phytoplankton living in surficial water layers. The three regimes exhibited similar strong diel cycles, the nocturnal fluxes being up to 100-fold lower than the daytime fluxes. High (or low) detrital DMSPp, fluxes were associated with high (or low) numbers of pteropods trapped inside the sampling cups. Thus, contamination of sinking material is likely to have occurred, promoting an overestimate of the... |
| Tipo: Text |
Palavras-chave: SULFUR; DMS; DMSP; ZOOPLANKTON; SEDIMENTATION. |
| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00098/20886/18500.pdf |
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| Cailliau, C; Belviso, S; Goutx, M; Bedo, A; Park, Y; Charriaud, E. |
| During summer 1994, the production regime at 2 sites located in the Indian sector of the Southern Ocean, one in the Permanent Open Ocean Zone (POOZ) at 52 degrees S, and a second in the Seasonal Ice Zone (SIZ) at 63 degrees S, was dominated by regeneration (0.3 < f-ratio < 0.4). Two time series, each of about 4 d, were performed over pre-determined time intervals of 4 h using a free-floating sediment trap set at 200 m at the 2 sites. Hourly variations of C, N, chlorophyll a (chl a) and its degradation products, taxon-specific pigments, lipid classes and dimethylsulfoniopropionate (DMSP) were measured simultaneously. Measurements in the water column were done during the sediment trap drifting. Fucoxanthin, a typical diatom pigment, was the major... |
| Tipo: Text |
Palavras-chave: Antarctic; Austral ocean; Sediment traps; Diel cycles; Phytoplankton; Pigments; Lipids; DMSP; DMS. |
| Ano: 1999 |
URL: https://archimer.ifremer.fr/doc/00240/35083/33651.pdf |
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