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Registros recuperados: 12 | |
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Mantoura, F; Coppola, Laurent; Cousin, M.; Antoine, David; Beguery, Laurent; Blain, Stephane; Bouin, Marie-noelle; Cadiou, Jean-francois; Durrieu De Madron, Xavier; Forget, Philippe; Fraunie, Philippe; Gojak, Carl; Gorsky, Gaby; Goyet, Catherine; Lebaron, Philippe; Lellouche, Jean-michel; Ludwig, Hubert; Molcard, Anne; Mortier, Laurent; Petit De La Villeon, Loic; Petrenko, Anne; Piazzola, J.; Queguiner, B.; Raimbault, Patrick; Rigaud, Vincent; Sempere, Richard; Tamburini, Jean-simon; Testor, Pierre; Vuillemin, Renaud; Zakardjian, B.. |
Tipo: Text |
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Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00122/23341/21166.pdf |
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Obernosterer, Ingrid; Catala, Philippe; Reinthaler, Thomas; Herndl, Gerhard J.; Lebaron, Philippe. |
The abundance and activity of heterotrophic and autotrophic organisms were determined in the surface microlayer (SML) at marine and estuarine sites in the NW Mediterranean Sea from May to July 2003. At all study sites, community respiration in the SML exceeded that in the subsurface water (SSW) by factors between 1.7 and 28. The abundance of heterotrophic bacteria and the major groups of the autotrophic community displayed consistent, but low enrichment factors (EF) for the SML (mean 1.3). In contrast, EF for the abundance of heterotrophic nanoflagellates and the concentration of particulate organic carbon were, on average, 4 and 7, respectively. Community respiration rates in the SML were related to the concentration of total organic carbon; however, no... |
Tipo: Text |
Palavras-chave: Surface microlayer; Community respiration; Net community production; Neuston. |
Ano: 2005 |
URL: https://archimer.ifremer.fr/doc/00243/35435/33960.pdf |
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Lebaron, Philippe. |
The purpose of this study is to investigate the behavior of two bacterial communities in the Thau brackish lagoon (Mediterranean coast of France) : the bacterial community from continental origin (allochtonous community) and the bacterial community endemic to the lagoon (autochtonous community). In a first step, the ability of two standard agar media (bioMerieux, nutrient agar at low salinity, 8; Difco, marine agar at high salinity, 34) to distinguish the two communities is tested. Then, abundances sampling of these two bacterial variables for several scales of observation permit to describe their spatial and temporal evolutions. The different encountered behaviors allow us (i) to improve the definition of an optimal sampling design for such bacterial... |
Tipo: Text |
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Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/00073/18379/15952.pdf |
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Urios, Laurent; Agogue, Hélène; Lesongeur, Francoise; Stackebrandt, Erko; Lebaron, Philippe. |
A novel aerobic, Gram-negative bacterium, named 13IX/A01/164(T), was isolated from surface waters in the coastal north-western Mediterranean Sea. Cells were motile, straight rods, 2-5 mu m long and 0-2 mu m wide, and formed orange colonies on marine agar medium. The G+C content of the genomic DNA of strain 13IX/A01/164T was 42 mol%. Phylogenetic analysis of the 16S rRNA gene sequence placed the strain in the phylum Bacteroidetes within the family Crenotrichaceae. On the basis of 16S rRNA gene sequence comparison and physiological and biochemical characteristics, this isolate represents a novel species of a new genus, for which the name Balneola vulgaris gen. nov., sp. nov. is proposed. The type strain of Balneola vulgaris is 13IX/A01/164T (=DSM 17893T=CIP... |
Tipo: Text |
Palavras-chave: Mediterranean sea; Coastal waters; Microbiology; Physiology; Biochemistry; Gene sequence; Balneola vulgaris. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2126.pdf |
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Troussellier, Marc; Bonnefont, Jean-luc; Courties, Claude; Derrien, Annick; Dupray, Elizabeth; Gauthier, Michel; Gourmelon, Michele; Joux, Fabien; Lebaron, Philippe; Martin, Yvan; Pommepuy, Monique. |
The effects of different environmental factors (nutrient deprivation, hyperosmotic shock, exposure to light) on enteric bacteria which have been transferred into the marine environment, have been studied experimentally (microcosms) by considering demographic, physiological and genetic responses in Escherichia coli or Salmonella typhimurium populations. Short-term experiments (less than or equal to 48 h) showed that nutrient deprivation induced limited changes in measured bacteriological variables, but when combined with hyperosmotic shock, it results in an energy charge decrease and inactivation of membrane transport. Light exposure mainly affects the colony-forming capacity of bacterial populations. Combining different stress factors confirmed the rapid... |
Tipo: Text |
Palavras-chave: Genetics; Cellular states; Physiology; Seawater; Enteric bacteria; Génétique; Etats cellulaires; Physiologie; Eau de mer; Entérobactéries. |
Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/1998/publication-845.pdf |
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Urios, Laurent; Michotey, Valerie; Intertaglia, Laurent; Lesongeur, Francoise; Lebaron, Philippe. |
A novel Gram-negative bacteria, named CZ41_10a(T), was isolated from coastal surface waters of the north-western Mediterranean Sea. Cells were motile, pleomorphic rods, 1.6 mu m long and 0.7 mu m wide and formed cream colonies on marine agar medium. The G+C content of the genomic DNA was 65 mol%. Phylogenetic analysis of 16S rRNA gene sequences placed the new isolate in the genus Thalassobaculum, a member of the family Rhodospirillaceae, class Alphaproteobacteria. Unlike Thalassobaculum litoreum CL-GR58(T), its closest relative, strain CZ41_10a(T) was unable to grow anaerobically and did not exhibit nitrate reductase activity. On the basis of DNA-DNA hybridization, fatty acid content and physiological and biochemical characteristics, this isolate... |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00001/11201/7846.pdf |
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Obernosterer, Ingrid; Catala, Philippe; Lebaron, Philippe; West, Nyree J.. |
We investigated the contribution of distinct bacterial groups to bulk abundance and leucine incorporation during a spring phytoplankton bloom induced by natural iron fertilization in the Southern Ocean (Kerguelen Ocean and Plateau Compared Study, January-February 2005). Oligonucleotide probes were designed to target five operational taxonomic units (OTUs) at a narrow phylogenetic level (>= 99% identity of the 16S ribosomal ribonucleic acid [rRNA] gene). During the peak of the phytoplankton bloom, the Roseobacter groups NAC11-7 and RCA, the OTUs SAR92 belonging to Gammaproteobacteria, and the Bacteroidetes OTU Agg58 dominated bulk abundance and leucine incorporation. These four OTUs disappeared with the decline of the bloom, when the cosmopolitan groups... |
Tipo: Text |
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Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00214/32503/30995.pdf |
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Doberva, Margot; Sanchez-ferandin, Sophie; Toulza, Eve; Lebaron, Philippe; Lami, Raphael. |
Quorum sensing (QS) is a cell-to-cell signalling pathway that allows bacteria to synchronize their genetic expression. It is mediated by autoinducers (AI), including (1) acyl-homoserine lactones (AHLs or AI-1), produced by Proteobacteria using AinS, LuxI and HdtS synthase families and (2) furanosyl-diester-borate (FDB or AI-2), produced by a large range of phylogenetically diverse bacteria and synthetized by the LuxS family. Few data have been collected about the presence and importance of QS in marine waters using culture independent methods. In this study, we examined the presence and the diversity of AI-1 and AI-2 synthases in the Global Ocean Sampling (GOS), a large metagenomic database, covering 68 stations across 3 oceans. We built 4 reference... |
Tipo: Text |
Palavras-chave: Quorum sensing; Acyl-homoserine lactone synthases; Global Ocean Sampling; Environmental metagenomes. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00615/72718/71710.pdf |
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Joux, Fabien; Agogue, Helene; Obernosterer, Ingrid; Dupuy, Christine; Reinthaler, Thomas; Herndl, Gerhard J.; Lebaron, Philippe. |
In an attempt to compare the microbial community structure between the sea surface microlayer (SML) and subsurface waters (SSW), we determined the enrichment factors (EF: the ratio of abundance or activity in the SML to abundance or activity in SSW) of 13 biological parameters. Samples were taken at 2 contrasting coastal sites in the Mediterranean Sea, corresponding to a high (Barcelona, Spain) and low (Banyuls-sur-Mer, France) urbanized area. Principal component analysis showed that temporal variability was much higher at Barcelona than at Banyuls, and that the characteristics of the SML and SSW samples were more closely related at Barcelona. At both sites, the SML was weakly enriched in heterotrophic bacteria (on average 1.1-fold), Synechococcus spp. (on... |
Tipo: Text |
Palavras-chave: Sea surface microlayer; Enrichment factor; Microbial structure; Virus-like particles; Bacteria; Microalgae; Nanoflagellates. |
Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00243/35434/33961.pdf |
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Registros recuperados: 12 | |
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