Data/hora: 05/06/2024 08:39:25

Provedor de dados: 	5	
País: 	France	
Título: 	Bacterial Dynamics in a Microphytobenthic Biofilm: a Tidal Mesocosm Approach	
Autores: 	Agogue, Helene; Mallet, Clarisse; Orvain, Francis; De Crignis, Margot; Mornet, Francoise; Dupuy, Christine.	
Data: 	2014-09	
Ano: 	2014	
Palavras-chave: 	Muddy sediment; Microphytobenthos; Bacteria; Extracellular polymeric substances; Interactions; Mesocosm.	
Resumo: 	In intertidal mudflats, during low tide exposure, microphytobenthos (MPB) migrate vertically through the surface sediment and form, with the heterotrophic bacteria, a transient biofilm. Inside this biofilm, multiple interactions exist between MPB and bacteria. These micro-organisms secrete a wide range of extracellular polymeric substances (EPS), which are major components of the biofilm matrix. In this study, we used a tidal mesocosm experiment in order to decipher the interactions of the MPB-EPS-bacteria complex within the biofilm. We tried to determine if the EPS could control bacterial activities and/or production and/or richness according to the age of the biofilm and to the immersion/emersion period. The dynamics of biomasses of MPB and prokaryotes, the bacterial production, the hydrolysis of predominating organic constituents in the dissolved organic carbon (DOC) pool (i.e., carbohydrates and polypeptides), and the bacterial structure were studied in relation to the different EPS fractions (carbohydrates and proteins: colloidal and bound) dynamics during 8 days. Our experiment had emphasized the influence of the environmental conditions (light, immersion/emersion) on the interactions within the biofilm and also on the effects on biofilm ageing. Bacterial production was always inhibited by the bound EPS-carbohydrate, especially during low tide. Our results suggest that the concentration and composition of EPS had a major role in the bacterial/MPB interactions: these interactions can be either positive or negative in order to regulate the productive phases of MPB and bacteria.	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	http://archimer.ifremer.fr/doc/00181/29271/27682.pdf

DOI:10.1016/j.seares.2014.03.003

http://archimer.ifremer.fr/doc/00181/29271/	
Editor: 	Elsevier Science Bv	
Formato: 	application/pdf	
Fonte: 	Journal Of Sea Research (1385-1101) (Elsevier Science Bv), 2014-09 , Vol. 92 , P. 36-45	
Fonte: 	2014 Elsevier B.V. All rights reserved.

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