| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
Dark metabolism and carbon-nitrogen uncoupling in the toxic dinoflagellate Alexandrium catenella (Dinophyceae)
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| Autores: |
Jauzein, Cecile
Collos, Yves
Laabir, Mohamed
Vaquer, Andre
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| Data: |
2011-11
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| Ano: |
2011
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| Palavras-chave: |
Diel cycle
Dark uptake
Nitrogen
Carbon
Uncoupling
Alexandrium catenella
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| Resumo: |
Uptake rates of three potential N-sources (ammonium, nitrate and N-urea) and two potential C-sources (HCO(3)(-) and C-urea) were estimated during growth of Alexandrium catenella in both light and dark phases. According to the variations observed in (13)C-isotopic ratio, A. catenella cells were not able to use C-urea. Furthermore, decreases in (13)C cell content during darkness revealed a probably high involvement of C recently fixed in dark respiration. Dark N-uptake capacities of A. catenella were characterized by dark/light uptake ratio of 27%, 43% and 65% for NO(3)(-), NH(4)(+) and N-urea, respectively. An accumulation of C-rich compounds during the light period was highlighted through strong diel variations in C:N ratio and would provide C and energy for these dark uptake processes indicating an uncoupling between N and C metabolism. Total costs in terms of C associated with dark N-uptake and assimilation were estimated and revealed that the main part of those costs may be associated with maintenance metabolism in A. catenella cells. The relatively low C-costs of biosynthesis in darkness suggest that dark uptake and C-storage strategies correspond to a benefit in terms of competitiveness for A. catenella, optimized by the migrating abilities of this species. (C) 2011 Elsevier B.V. All rights reserved.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
http://archimer.ifremer.fr/doc/00056/16699/14199.pdf
DOI:10.1016/j.hal.2011.08.002
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| Editor: |
Elsevier Science Bv
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| Relação: |
http://archimer.ifremer.fr/doc/00056/16699/
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| Formato: |
application/pdf
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| Fonte: |
Harmful Algae (1568-9883) (Elsevier Science Bv), 2011-11 , Vol. 11 , P. 73-80
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| Direitos: |
2011 Elsevier B.V. All rights reserved.
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