Consulta: subjectFacets:"Microbial mats"
Registros recuperados: 6
Data/hora: 14/06/2024 03:22:54

Benthic Foraminifera in Arctic Methane Hydrate Bearing Sediments
Provedor de dados: 5
Autores: Dessandier, Pierre-antoine; Borrelli, Chiara; Kalenitchenko, Dimitri; Panieri, Giuliana.
Benthic foraminifera have been widely used as proxy for paleo-methane emissions, mainly based on their stable isotopic signature. In cold seeps, the ecology of these organisms remains uncertain, in particular their ability to thrive during active phases of seepage. In this study, we evaluate the benthic foraminiferal response to methane seepage in Arctic sediments. We do so by examining living and dead benthic foraminiferal assemblages (&gt;63 mu m) of 11 push cores collected in two of the most active pockmarks (Lunde and Lomvi) along Vestnesa Ridge, offshore western Svalbard. Benthic foraminiferal assemblages are interpreted in the context of sediment geochemistry, seafloor images, and pore water analyses, which are used to characterize the different...
Tipo: Text
Palavras-chave: Benthic foraminiferal assemblages; Methane advection; Methane diffusion; Arctic Ocean; Microbial mats.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00667/77894/80079.pdf

Seventy-year chronology of Salinas in southern France: coastal surfaces managed for salt production and conservation issues for abandoned sites
Provedor de dados: 5
Autores: De Wit, Rutger; Vincent, Alice; Foulc, Ludovic; Klesczewski, Mario; Scher, Olivier; Loste, Claudine; Thibault, Marc; Poulin, Brigitte; Ernoul, Lisa; Boutron, Olivier.
After World War II, twenty-nine coastal Salinas (122 km2), located in the vicinity of coastal lagoons and in deltas, were exploited along the Mediterranean coastlines in South France. Today, only five of these are still actively producing salt, currently representing 175 km2. Concomitant with the abandonment of many of the smaller Salinas, the larger Salinas in the Rhône delta (Camargue) strongly increased their surfaces at the expense of natural ecosystems, of which a part has also been abandoned after 2009. This paper documents these changes in landscape use by chronological GIS mapping and describes the fate of the 91 km2 of abandoned Salina surfaces. The majority of this area (88 km2) is included in the Natura 2000 network, among which most (74 km2)...
Tipo: Text
Palavras-chave: Corine land cover 4.2.2; Microbial mats; Waterfowl; Halophytes; Coastal lagoon; Delta.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00486/59748/62853.pdf

Microbial mats in French Polynesia and their biotechnological applications
Provedor de dados: 5
Autores: Guezennec, Jean; Moppert, Xavier; Raguenes, Gerard; Richert, Laurent; Costa, Bernard; Simon-colin, Christelle.
It is well known that microorganisms well-adapted to survival in extreme ecosystems could be considered as new sources of biomolecules that have biotechnological importance. On French Polynesian atolls, microbial mats are developing in water ponds exposed to fluctuations in physical and chemical parameters. In these microbial mats, which are called "kopara" by the inhabitants, bacteria coexist with cyanobacteria, and a synergistic relationship may exist between these two types of living microorganisms. A large number of cyanobacteria and bacteria have been isolated from different mats. Under laboratory conditions, these microorganisms were shown to produce various exopolymers, including exopolysaccharides and poly-beta-hydroxyalkanoates, along with...
Tipo: Text
Palavras-chave: Microbial mats; Kopara; Biopolymers; Exopolysaccharides; Poly-beta-hydroxyalkanoates.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00029/14058/11423.pdf

Benthic microalgal communities in the inner part of the Bahia Blanca estuary (Argentina): a preliminary qualitative study
Provedor de dados: 5
Autores: Parodi, Er; Barria De Cao, S.
The intertidal zone of the inner part of the Bahia Blanca estuary, Argentina is characterised by the presence of muddy tidal flats and salt marshes, habitats for burrowing crabs and halophytic plants. The surface layer of the sediments is composed of silt and clay. The sediments are substrate for the proliferation of benthic microalgal communities. The aim of this study was to analyse qualitatively the species composition of these communities and their role in the stabilisation of the sediments. Samples came from two stations: Puerto Cuatreros and Villarino Viejo. Puerto Cuatreros is an old pier without harbour activities closer than Villarino Viejo to the harbour zone affected by dredging. Both stations showed similar physical and chemical parameters. In...
Tipo: Text
Palavras-chave: Microphytobenthos; Stabilisation des sédiments; Benthic microalgal communities; Microbial mats; Sediments stabilisation.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00322/43311/42963.pdf

Cyanobacterial populations that build 'kopara' microbial mats in Rangiroa, Tuamotu Archipelago, French Polynesia
Provedor de dados: 5
Autores: Richert, Laurent; Golubic, Stjepko; Le Guedes, Roland; Herve, Annie; Payr, Claude.
Cyanobacterial populations, the primary producers and builders of 'kopara' microbial mats were studied in four selected ponds along the rim of the Rangiroa Atoll, French Polynesia using a polyphasic approach. Seven isolates were maintained in uni-cyanobacterial cultures, characterized morphotypically and phylogenetically by evaluating sequences of the 16S rRNA gene of about 620 base pairs in length. Cyanobacteria in natural populations were analyzed microscopically, characterized morphotypically, and compared with cultured strains. Three of the isolates were identified in the field samples: Lyngbya aestuarii, Johannesbaptistia pellucida and Chroococcus submarinus were present in the mats only as minor components, whereas the species of Schizothrix that...
Tipo: Text
Palavras-chave: 16S rRNA; Polyphasic approach; Phylogeny; Microbial mats; Microbial ecology; Kopara; Diversity; Cyanobacteria; Culture.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2050.PDF

Investigations into the uptake of copper, iron and selenium by a highly sulphated bacterial exopolysaccharide isolated from microbial mats
Provedor de dados: 5
Autores: Moppert, Xavier; Le Costaouec, Tinaig; Raguenes, Gerard; Courtois, Anthony; Simon-colin, Christelle; Crassous, Philippe; Costa, Bernard; Guezennec, Jean.
A bacterium isolated from microbial mats located on a polynesian atoll produced a high molecular weight (3,000 kDa) and highly sulphated exopolysaccharide. Previous studies showed that the chemical structure of this EPS consisted of neutral sugars, uronic acids, and high proportions of acetate and sulphate groups. The copper- and iron-binding ability of the purified pre-treated native EPS was investigated. Results showed that this EPS had a very high affinity for both copper (9.84 mmol g(-1) EPS) and ferrous iron (6.9 mmol g(-1) EPS). Amazingly, this EPS did not show any affinity for either ferric ions or selenium salts. This finding is one of the first steps in assessing the biotechnological potential of this polysaccharide.
Tipo: Text
Palavras-chave: Sulphated exopolysaccharide; Microbial mats; Iron; Copper; Binding capacity.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6397.pdf