Data/hora: 08/06/2024 17:45:03

Provedor de dados: 	5	
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.