A5091756586- Marine and coastal ecosystems
- Microbial Community Ecology and Physiology
- Marine Biology and Ecology Research
- Oceanographic and Atmospheric Processes
- Maritime Navigation and Safety
- Maritime Transport Emissions and Efficiency
- Offshore Engineering and Technologies
- Protist diversity and phylogeny
- Atmospheric and Environmental Gas Dynamics
- Wastewater Treatment and Nitrogen Removal
- Single-cell and spatial transcriptomics
- Ocean Acidification Effects and Responses
- Marine Bivalve and Aquaculture Studies
- Marine and fisheries research
- Geochemistry and Geologic Mapping
- Methane Hydrates and Related Phenomena
- Mine drainage and remediation techniques
- Isotope Analysis in Ecology
- Marine Ecology and Invasive Species
- Diatoms and Algae Research
- Aquatic Ecosystems and Phytoplankton Dynamics
- Atmospheric chemistry and aerosols
- Ocean Waves and Remote Sensing
- Identification and Quantification in Food
- Marine Biology and Environmental Chemistry
Aix-Marseille Université
2016-2025
Université de Toulon
2015-2025
Institut de Recherche pour le Développement
2016-2025
Centre National de la Recherche Scientifique
2016-2025
Institut Méditerranéen d’Océanologie
2015-2024
Institut Pprime
2024
Château Gombert
2024
University of Chinese Academy of Sciences
2021
Purdue University West Lafayette
2003-2018
Laboratoire de Biotechnologie et Chimie Marines
2005-2018
Abstract Diatoms are one of the major primary producers in ocean, responsible annually for ~20% photosynthetically fixed CO 2 on Earth. In oceanic models, they typically represented as large (>20 µm) microphytoplankton. However, many diatoms belong to nanophytoplankton (2–20 and a few species even overlap with picoplanktonic size-class (<2 µm). Due their minute size difficulty detection poorly characterized. Here we describe massive spring bloom smallest known diatom ( Minidiscus )...
ABSTRACT The membrane integrity of a cell is well-accepted criterion for characterizing viable (active or inactive) cells and distinguishing them from damaged membrane-compromised cells. This information major importance in studies the function microbial assemblages natural environments, order to assign bulk activities measured by various methods very active that are effectively responsible observations. To achieve this task bacteria freshwater marine waters, we propose nucleic acid...
Oxygen availability drives changes in microbial diversity and biogeochemical cycling between the aerobic surface layer anaerobic core nitrite-rich anoxic marine zones (AMZs), which constitute huge oxygen-depleted regions tropical oceans. The current paradigm is that primary production nitrification within oxic fuel processes of AMZs, where 30-50% global nitrogen loss takes place. Here we demonstrate oxygenic photosynthesis secondary chlorophyll maximum (SCM) releases significant amounts O2...
Nitrogen is essential for life but often a major limiting nutrient growth in the ocean. Biological dinitrogen fixation source of new nitrogen to surface waters and promotes marine productivity. Yet fate diazotroph-derived (DDN) ecosystems has been poorly studied, its transfer auto- heterotrophic plankton not measured. Here, we use high-resolution nanometer scale secondary ion mass spectrometry (nanoSIMS) coupled with 15N2 isotopic labelling flow cytometry cell sorting examine DDN specific...
Dynamics of autotrophic and heterotrophic prokaryotes their consumption by nanoflagellates were studied in the euphotic zone at nine stations located from Levantine Basin (34°E) to Balearic sea (5°E) June 1999. Bacterial biomass constituted largest proportion living all stations. Integrated bacterial production furthest east station, was sixfold lower than integrated west (13 75 mg C m−2 d−1 respectively). Estimated nanoflagellate bacterivory accounted for 45–87% production. Small protists...
Despite recent progress in cell-analysis technology, rapid classification of cells remains a very difficult task. Among the techniques available, flow cytometry (FCM) is considered especially powerful, because it able to perform multiparametric analyses single biological particles at high rate-up several thousand per second. Moreover, FCM nondestructive, and cytometric analysis can be performed on live cells. The current limit for simultaneously detectable fluorescence signals around 8-15...
Water safety is a major concern for public health and natural environment preservation. We propose to use bacteriophages develop biosensor tools able detect human animal pathogens present in water. For this purpose, we take advantage of the highly discriminating properties bacteriophages, which specifically infect their bacterial hosts. The challenge fluorescent reporter protein that will be synthesized, thus detected, only once specific recognition step between genetically modified...
Conceived as a major new tool for climate studies, the Surface Water and Ocean Topography (SWOT) satellite mission will launch in late 2021 can retrieve dynamics of ocean upper layer at an unprecedented resolution few kilometers. During calibration validation (CalVal) phase 2022, be 1-day-repeat fast sampling orbit with enhanced temporal but sacrificing spatial coverage. This is ideal opportunity - unique many years to come coordinating in-situ experiments during same period focused study...
Abstract Multispectral and hyperspectral flow cytometry (FC) instruments allow measurement of fluorescence or Raman spectra from single cells in flow. As with conventional FC, spectral overlap results the measured signal any given detector being a mixture signals multiple labels present analyzed cells. In contrast to traditional polychromatic these devices utilize number detectors (or channels multispectral arrays) that is larger than labels, no particular priori dedicated label. This...
Stable isotope ratios of six size fractions zooplankton (80 to .2000mm) were analyzed seasonally in 2009-2010 at the SOMLIT site Bay Marseille.Isotopic generally increased with size.The highest d 15 N values observed 1000 -2000 mm fraction.The largest class (.2000 mm), dominated by gelatinous plankton, had lower due low isotopic signatures most these organisms.In larger (.1000 measured taxon level.Brachyuran, stomatopod, teleost and cephalopod larvae showed values, salps pteropods lowest...
When immersed in seawater, substrates are rapidly colonized by both micro- and macroorganisms. This process is responsible for important economic ecological prejudices, particularly when related to ship hulls or aquaculture nets. Commercial antifouling coatings supposed reduce biofouling, i.e., macrofoulers. In this study, biofilms that primarily settled on seven different (polyvinyl chloride [PVC], a fouling release coating [FRC], five self-polishing copolymer [SPC], including four...
Abstract One pathway by which the oceans influence climate is via emission of sea spray that may subsequently cloud properties. Sea emissions are known to be dependent on atmospheric and oceanic physicochemical parameters, but potential role ocean biology fluxes remains poorly characterized. Here we show a consistent significant relationship between seawater nanophytoplankton cell abundances sea-spray derived Cloud Condensation Nuclei (CCN) number fluxes, generated using water from three...
The recent development of biological sensors has extended marine plankton studies from conducting laboratory bench work to in vivo and real-time observations. Flow cytometry (FCM) shed new light on microorganisms since the 1980s through its single-cell approach robust detection smallest cells. FCM records valuable optical properties scattering fluorescence cells passing a single file front narrow-collimated source, recording tens thousands within few minutes. Depending instrument settings,...
Activation of the cellular stress pathways (c-Jun N-terminal kinase [JNK] and p38 mitogen-activated protein [MAP] kinase) is linked to apoptosis. However, whether both are required for apoptosis remains unresolved. Hepatitis B virus X (pX) activates MAP JNK and, in response weak apoptotic signals, sensitizes hepatocytes Employing hepatocyte cell lines expressing pX, which was regulated by tetracycline, we investigated mechanism pathway activation. Inhibition rescues 80% initiation...
Phytoplankton observation is the product of a number trade-offs related to sampling processes, required level diversity and size spectrum analysis capabilities techniques involved. Instruments combining morphological high-frequency for phytoplankton cells are now available. This paper presents an application automated high-resolution flow cytometer Cytosub as tool analysing phytoplanktonic in their natural environment. High resolution data from temporal study Bay Marseille (analysis every 30...
The breaking of near-inertial wave (NIW) trapped in anticyclones after strong wind events is a well-known pathway for kinetic energy dissipation below the mixed layer ocean and one mechanisms by which responds to modified patterns under climate change. In Mediterranean Sea, where turbulence generally low far from topographic boundaries, NIW trapping has been documented only few large (>100 km) energetic mesoscale features. Whether restricted these isolated semi-permanent features or more...
Interactions between physical and biogeochemical processes have traditionally been studied at ocean basin scales or in regions with by large mesoscale features. At finer scales, such as fronts small eddies, modeling studies offered valuable insights into how features influence biogeochemistry. However, these interactions remain understudied using empirical data due to the challenges of identifying sampling dynamic structures. In oligotrophic regions, vertical distribution nutrients plays a...
Phytoplankton communities, shaped by complex water dynamics, are vital to ecosystem structure and play a key role in oceanic productivity the biological carbon pump. Previous studies suggest that fine-scale O(1-100km, day-week) physical features significantly influence phytoplankton production, distribution diversity highly productive dynamic regions. However, oligotrophic moderate energy conditions, representing significant part of global ocean, how dynamics impact remains open question....
In the ocean, fine scales (1-100 km) are short-lived structures (days to weeks) that drive ocean physics, chemistry, ecology, and can influence climate. Among them, fronts ubiquitous fine-scale physical features separate different water masses create gradients of biogeochemical contents. Fronts often associated with vertical mixing column, allowing availability nutrients support phytoplankton dynamics. However, how such affect distribution is not well understood, especially in oligotrophic...
Planktonic microorganisms play a crucial role in marine ecosystems by contributing to nutrient cycles, regulating climate, and supporting the food web. However, it is still unclear what extent they can continue provide these essential services as face increasing pressures from climate change human activities (Abreu et al., 2022). Understanding how environmental anthropogenic changes affect plankton communities guide sustainable fisheries management reduce our impact on ocean health.Due their...
Addressing hydrological, biogeochemical and biological variability in marine systems at different scales is essential for understanding their functioning fate the context of global change increasing anthropogenic pressure. Sub-mesoscale features processes are particularly relevant coastal, marginal shelf seas, frontal (such as Regions Of Freshwater Influence, tidal fronts, upwelling eddies), being sensitive to extreme events influencing human health, economy, well-being. Phytoplankton...
Abstract. Observations, models and theory have suggested that ocean fronts are ecological hotspots, generally associated with higher diversity biomass across many trophic levels. Nutrient injections often chlorophyll concentrations at fronts, but the response of zooplankton community is largely unknown. The present study investigates mesozooplankton stocks composition during late spring, northeast Menorca along two north-south transects crossed North Balearic Front (NBF) separating central...
AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsSpecials 43:267-276 (2006) - doi:10.3354/ame043267 Pressure effects on surface Mediterranean prokaryotes and biogenic silica dissolution during a diatom sinking experiment Christian Tamburini1,*, Jean Garcin1, Gérald Grégori1, Karine Leblanc2, Peggy Rimmelin2, David L. Kirchman3 1Laboratoire Microbiologie, Géochimie et Ecologie...