Data/hora: 09/06/2024 04:32:36

Provedor de dados: | Institutional Archive of Ifreme (ArchiMer)
País: | France
Título: | Dark metabolism and carbon-nitrogen uncoupling in the toxic dinoflagellate Alexandrium catenella (Dinophyceae)
Autores: | Jauzein, Cecile; Collos, Yves; Laabir, Mohamed; Vaquer, Andre.
Data: | 2011-11
Ano: | 2011
Palavras-chave: | Diel cycle; Dark uptake; Nitrogen; Carbon; Uncoupling; Alexandrium catenella.
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.
Tipo: | Text
Idioma: | Inglês

Identificador:

http://archimer.ifremer.fr/doc/00056/16699/14199.pdf

DOI:10.1016/j.hal.2011.08.002

Editor: | Elsevier Science Bv
Relação: | http://archimer.ifremer.fr/doc/00056/16699/
Formato: | application/pdf
Fonte: | Harmful Algae (1568-9883) (Elsevier Science Bv), 2011-11 , Vol. 11 , P. 73-80
Fonte: | 2011 Elsevier B.V. All rights reserved.