Consulta: creatorFacets:"Jesus, Bruno"
Registros recuperados: 6
Data/hora: 10/06/2024 06:36:01

Subtidal Microphytobenthos: A Secret Garden Stimulated by the Engineer Species Crepidula fornicata
Provedor de dados: 5
Autores: Androuin, Thibault; Polerecky, Lubos; Decottignies, Priscilla; Dubois, Stanislas; Dupuy, Christine; Hubas, Cedric; Jesus, Bruno; Le Gall, Erwan; Marzloff, Martin; Carlier, Antoine.
The slipper limpet Crepidula fornicata is an emblematic invasive species along the northeast Atlantic coast. This gregarious gastropod lives in stacks of several individuals and forms extended beds in shallow subtidal areas. The effects of this engineer species on the colonized habitat can be physical (e.g., presence of hard-shell substrates with uneven topography) or biological (e.g., nutrient enrichment by direct excretion or via biodeposition). We hypothesized that through biological activity, nutrient fluxes at the sediment-water interface are enhanced, leading to stimulated primary productivity by microphytobenthos (MPB) associated with Crepidula beds. To test this fertilization hypothesis, we conducted a 10-day mesocosm experiment using C. fornicata...
Tipo: Text
Palavras-chave: Crepidula fornicata; Engineer species; Subtidal microphytobenthos; Fertilization; Hyperspectral imaging.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00472/58338/60893.pdf

Response of a kleptoplastidic foraminifer to heterotrophic starvation: photosynthesis and lipid droplet biogenesis
Provedor de dados: 5
Autores: Jauffrais, Thierry; Lekieffre, Charlotte; Schweizer, Magali; Jesus, Bruno; Metzger, Edouard; Geslin, Emmanuelle.
The aim of this work is to document the complex nutritional strategy developed by kleptoplastic intertidal foraminifera. We study the mixotrophic ability of a common intertidal foraminifer, E. williamsoni, by (1) investigating the phylogenetic identity of the foraminiferal kleptoplasts, (2) following their oxygenic photosynthetic capacity, and (3) observing the modification in cellular ultrastructural features in response to photoautotrophic conditions. This was achieved by coupling molecular phylogenetic analyses and TEM observations with non-destructive measurements of kleptoplast O2 production over a 15-day experimental study. Results show that the studied E. williamsoni actively selected kleptoplasts mainly from pennate diatoms and had the ability to...
Tipo: Text
Palavras-chave: Foraminifera; Electron microscopy; DNA barcoding; Kleptoplasty; Lipids.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00487/59894/63074.pdf

Kleptoplastidic benthic foraminifera from aphotic habitats: Insights into assimilation of inorganic C, N, and S studied with sub-cellular resolution
Provedor de dados: 5
Autores: Jauffrais, Thierry; Lekieffre, Charlotte; Schweizer, Magali; Geslin, Emmanuelle; Metzger, Edouard; Bernhard, Joan M.; Jesus, Bruno; Filipsson, Helena L.; Maire, Olivier; Meibom, Anders.
The assimilation of inorganic compounds in foraminiferal metabolism compared to predation or organic matter assimilation is unknown. Here we investigate possible inorganic‐compound assimilation in Nonionellina labradorica, a common kleptoplastidic benthic foraminifer from Arctic and North Atlantic sublittoral regions. The objectives were to identify the source of the foraminiferal kleptoplasts, assess their photosynthetic functionality in light and darkness, and investigate inorganic nitrogen and sulfate assimilation. We used DNA barcoding of a ~830 bp fragment from the SSU rDNA to identify the kleptoplasts, and correlated transmission electron microscopy and nanometer‐scale secondary ion mass spectrometry (TEM‐NanoSIMS) isotopic imaging to study...
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00460/57188/59151.pdf

Assessing Alternative Microscopy-Based Approaches to Species Abundance Description of Intertidal Diatom Communities
Provedor de dados: 5
Autores: Ribeiro, Lourenço; Brotas, Vanda; Hernandez Farinas, Tania; Jesus, Bruno; Barille, Laurent.
Diatoms usually dominate microphytobenthic biofilms in coastal and estuarine intertidal environments. Yet, functional studies on biofilms often skip species analysis because benthic diatoms are notoriously difficult to extract from sediments and challenging to identify at that taxonomic level. Valid, less time-consuming alternatives would surely be welcomed and increase the inclusion of community structure information in microphytobenthos (MPB) ecophysiological studies. Starting with an original 181-species abundances matrix (OSM), obtained during a 2-year spatial–temporal survey in a Tagus Estuary intertidal flat with contrasting sediment textures, the current study assessed the effectiveness of several approaches to species abundances analysis. The...
Tipo: Text
Palavras-chave: Diatoms; Community structure; Intertidal flats; Microphytobenthos; Multivariate analysis; Taxonomic sufficiency.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00610/72187/70963.pdf

Effect of light on photosynthetic efficiency of sequestered chloroplasts in intertidal benthic foraminifera (Haynesina germanica and Ammonia tepida)
Provedor de dados: 5
Autores: Jauffrais, Thierry; Jesus, Bruno; Metzger, Edouard; Mouget, Jean-luc; Jorissen, Frans; Geslin, Emmanuelle.
Some benthic foraminifera have the ability to incorporate functional chloroplasts from diatoms (kleptoplasty). Our objective was to investigate chloroplast functionality of two benthic foraminifera (Haynesina germanica and Ammonia tepida) exposed to different irradiance levels (0, 25, 70 mot photon m(-2) s(-1)) using spectral reflectance, epifluorescence observations, oxygen evolution and pulse amplitude modulated (PAM) fluorometry (maximum photosystem II quantum efficiency (Fv/Fm) and rapid light curves (RLC)). Our results clearly showed that H. germanica was capable of using its kleptoplasts for more than 1 week while A. tepida showed very limited kleptoplastic ability with maximum photosystem II quantum efficiency (Fv/Fm = 0.4), much lower than H....
Tipo: Text
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00457/56899/58754.pdf

Denitrification by benthic foraminifera and their contribution to N-loss from a fjord environment
Provedor de dados: 5
Autores: Choquel, Constance; Geslin, Emmanuelle; Metzger, Edouard; Filipsson, Helena L.; Risgaard-petersen, Nils; Launeau, Patrick; Giraud, Manuel; Jauffrais, Thierry; Jesus, Bruno; Mouret, Aurélia.
Oxygen availability impacts the marine nitrogen cycle at a range of spatial and temporal scales. Invasive organisms have shown to sustainably affect sediment geochemistry and benthic ecology. Nonionella sp. T1 was recently described as an invasive benthic foraminifer in the North Sea region. Here, we demonstrate the impact of this denitrifying species on the foraminifera fauna and the nitrogen cycle of the Gullmar Fjord (Sweden). The foraminifera contribution to benthic denitrification was estimated by coupling living foraminifera micro-distribution, denitrification rate measurement and sedimentary nitrate 2D distribution. Nonionella sp. T1 dominated the foraminifera fauna and could denitrify up to 50–100 % of nitrate porewater in oxygenated bottom waters...
Tipo: Text
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00643/75482/76327.pdf