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| Azandegbe, Afi; Gamier, Matthieu; Andrieux, Francoise; Kerouel, Roger; Philippon, Xavier; Nicolas, Jean-louis. |
| Vibrio aestuarianus is frequently found in coastal areas and can infect and induce mortalities in the pacific oyster Crassostrea gigas. However, nothing is known about its distribution and seasonality in the estuarine environment, especially where oyster farming is practiced. Its occurrence was investigated in sediment and oyster haemolymph at 2 oyster farms in Brittany (France) over 2 yr during 2 periods, from June to September 2007 and from February to June 2008. Total heterotrophic bacteria (HB) were cultured on marine agar while total Vibrio spp. and V. aestuarianus were selectively numerated using thiosulfate citrate bile salts sucrose agar (TCBS agar) and the species-specific hybridisation method, respectively. PCR was performed to detect V.... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; Crassostrea gigas Sediment; Seasonal abundance; Colony-blot. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00017/12813/9756.pdf |
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| Azandegbe, Afi; Poly, Franck; Andrieux, Francoise; Kerouel, Roger; Philippon, Xavier; Nicolas, Jean-louis. |
| Bacterial community structure and some biogeochemical parameters were studied in the sediment of two Pacific oyster farming sites, Aber Benoît (AB) and Rivière d'Auray (RA) in Brittany (France), to examine the ecological impact of oysters and to evaluate the emission of sulfide and ammonia from sediment. At AB, the organic matter accumulated in the sediment beneath the oyster tables was rapidly mineralized, with strong fluxes of ammonia and sulfide that reached 1014 μmol m−2 h−1 - and 215 μmol m−2 h−1, respectively, in June 2007. At RA, the fluxes were about half as strong on average and better distributed through the year. The ammonia and sulfide concentrations in the overlying water never reached levels that would be toxic to oysters in either site, nor... |
| Tipo: Text |
Palavras-chave: Sediment; Biogeochemical parameters; Fluxes; Bacterial structure; Crassostrea gigas. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00079/19010/17083.pdf |
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| Andrieux, Francoise; Azandegbe, Afi; Caradec, Florian; Philippon, Xavier; Kerouel, Roger; Youenou, Agnes; Nicolas, Jean-louis. |
| This study aims to compare the impact of oyster cultures on diagenetic processes and the phosphorus cycle in the sediments of the Aber Benoît and the Rivière d’Auray, estuary of Brittany, France. Our results showed clear evidence of the seasonal impact of oyster cultures on sediment characteristics (grain size, organic matter parameters), and the phosphorus cycle, especially in the Aber Benoît. At this site, seasonal variations of sulfide and Fe concentrations in pore waters, as well as Fe-P concentrations in the solid-phase highlighted a shift from a system governed by iron reduction (Reference) to a system governed by sulphate reduction (Beneath Oyster). This could be partly explained by the increase in labile organic matter (ie, biodeposits) beneath... |
| Tipo: Text |
Palavras-chave: Sediment; Phosphorus; Sulfide; Dissolved Fe/P ratios; Labile organic matter; Oyster cultures. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00209/32003/30441.pdf |
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