A5009576956- Microbial Community Ecology and Physiology
- Genomics and Phylogenetic Studies
- Methane Hydrates and Related Phenomena
- Metal Extraction and Bioleaching
- Protist diversity and phylogeny
- Hydrocarbon exploration and reservoir analysis
- Atmospheric and Environmental Gas Dynamics
- Anaerobic Digestion and Biogas Production
- Marine Biology and Ecology Research
- DNA Repair Mechanisms
- Polar Research and Ecology
- Microbial metabolism and enzyme function
- Bacteriophages and microbial interactions
- Paleontology and Stratigraphy of Fossils
- Bacterial Genetics and Biotechnology
- Chemical Synthesis and Characterization
- DNA and Nucleic Acid Chemistry
- Virology and Viral Diseases
- Aquaculture disease management and microbiota
- Minerals Flotation and Separation Techniques
- Probiotics and Fermented Foods
- Actinomycetales infections and treatment
- Drilling and Well Engineering
- Carcinogens and Genotoxicity Assessment
- Coral and Marine Ecosystems Studies
Université de Bretagne Occidentale
2014-2023
Centre National de la Recherche Scientifique
2008-2023
Ifremer
2011-2023
Biology of Extremophiles Laboratory
2001-2022
Institut Universitaire Européen de la Mer
2003-2019
Laboratoire des Sciences de l'Environnement Marin
2017
Centre National pour la Recherche Scientifique et Technique (CNRST)
1998-2008
Station Biologique de Roscoff
1994-1999
Sorbonne Université
1999
Centre de Gestion Scientifique
1995
ABSTRACT Activity measurements by radioisotopic methods and cultural molecular approaches were used in parallel to investigate the microbial biodiversity its physiological potential formation waters of Samotlor high-temperature oil reservoir (Western Siberia, Russia). Sulfate reduction with rates not exceeding 20 nmol H 2 S liter −1 day occurred at 60 80°C. In upper horizons (AB, A, B), methanogenesis (lithotrophic and/or acetoclastic) was detected only wells which sulfate did occur. some...
Enrichments for anaerobic organotrophic hyperthermophiles were performed with hydrothermal chimney samples collected at the Guaymas Basin (27 degrees 01' N, 111 24' W). Positive enrichments submitted to gamma-irradiation a dose of 30 kGy. One resistant strains, designated strain EJ3(T), formed regular motile cocci. The new grew between 55 and 95 C, an optimum growth temperature 88 C. optimal pH was 6.0, NaCl concentration around 20 g l(-1). Strain EJ3(T) obligately heterotroph that utilized...
A mesophilic, aerobic, non-flagellated, gliding bacterium, forming yellow colonies and designated DsijT, was isolated from a red alga on the sea-shore of Roscoff, Brittany, France. DsijT selected for its ability to actively degrade both agars carrageenans. The Gram-negative cells occurred singly or in pairs as long rods. temperature range growth 13-45 degrees C, with an optimum at 35 C. pH C 6.0 8.5, around 7.0. NaCl concentrations required 7.0 ranged 5 60 g l(-1), 25 l(-1). G+C content...
Novel thermophilic, anaerobic, Gram-positive, rod-shaped bacteria, strains SL9 and OCA1, were isolated from oilfields in France Australia, respectively. Both strains, together with Thermoanaerobacter yonseiensis KB-1 T (=DSM 13777 ), tengcongensis MB4 15242 ) Carboxydibrachium pacificum JM 12653 possessed genomic (DNA–DNA hybridization studies) phylogenetic similarities subterraneus SEBR 7858 13054 which was recently an oilfield reservoir south-west France. Marked phenotypic differences...
The genome sequence of Thermotoga maritima revealed that 24% its open reading frames (ORFs) showed the highest similarity scores to archaeal genes in BLAST analyses. Here we screened 16 strains from genus and other related Thermotogales for occurrence two these "archaeal" genes: gene encoding large subunit glutamate synthase (gltB) myo-inositol 1P (ino1). Both were restricted species within Thermotogales. distribution genes, along with results phylogenetic analyses, they acquired Archaea...
Significance Much of Earth’s volcanism occurs in the deep sea, yet little is known about microbial communities inhabiting such extreme and dynamic systems. Using a multidisciplinary approach to study distinct hydrothermal systems at Brothers submarine arc volcano, we provide insights into how community composition function reflect subtly different fluid chemistries resulting from subsurface interactions with alteration mineral assemblages. These variations can be traced hydrogeologic history...
An autotrophic, hyperthermophilic methanogen (M7T) was isolated from a deep-sea hydrothermal chimney sample collected on the East Pacific Rise at depth of 2600 m. The coccoid-shaped cells are flagellated and exhibit sligh tumbling motility. temperature range for growth pH 6·5 49–89 °C, with optimum 80 °C. 6·5, NaCI concentration around 25 g I–1. new isolat used H2 CO2 as only substrates methane production. Tungsten, selenium yeast extract stimulated significantly. In presence organism...
A thermophilic, anaerobic, strictly autotrophic, sulphur-reducing bacterium, designated BSAT (T = type strain), was isolated from a deep-sea hydrothermal chimney sample collected at the mid-Atlantic ridge. Gram-negative cells occurred singly or in pairs as small highly motile rods. Spores were not observed. The temperature range for growth 40 to 75 degrees C, with an optimum 70 C. pH C 4.4 7.5, around 6.0. sea salt concentration 15-70 gI(-1) 35 gI(-1). Elemental sulphur, thiosulphate and...
An autotrophic, extremely thermophilic methanogen (MET) was isolated from a deep-sea hydrothermal chimney sample collected on the Mid-Atlantic Ridge at depth of 3000 m. The heavily flagellated cells are motile and coccoid shaped. new strain grows between 55 91 °C, with an optimum growth temperature 85 °C. pH for is 6.5, sea salt concentration around 25 g I-1. organism uses H2 CO2 as only substrate methane production. Tungsten, selenium yeast extract stimulate significantly. In presence H2,...
A thermophilic, marine, anaerobic, chemolithoautotrophic, sulfate-reducing bacterium, strain CIR29812 T , was isolated from a deep-sea hydrothermal vent site at the Kairei field on Central Indian Ridge. Cells were Gram-negative motile rods that did not form spores. The temperature range for growth 55–80 °C, with an optimum 70 °C. NaCl concentration 10–35 g l −1 25 . pH 6–6·7, approximately 6·25. H 2 and CO only electron donor carbon source found to support of strain. However, several organic...
A novel moderately thermophilic, microaerobic to anaerobic, chemolithoautotrophic bacterium, designated strain CR T , was isolated from a deep-sea hydrothermal vent site at 36°N on the Mid-Atlantic Ridge. Cells were Gram-negative, non-motile rods. The organism grew 45–65 °C and pH 6·5–7·4, with optimum growth 55 6·9–7·1. NaCl range for 5–50 g l −1 (optimum 30 ). Strain an obligate chemolithoautotroph, growing H 2 as energy source, sulfur, nitrate or oxygen electron acceptors CO carbon...
A novel, strictly anaerobic, methylotrophic marine methanogen, strain SLH33(T), was isolated from deep sediment samples covered by an orange microbial mat collected the Napoli Mud Volcano. Cells of SLH33(T) were Gram-stain-negative, motile, irregular cocci that occurred singly. utilized trimethylamine, dimethylamine, monomethylamine, methanol, betaine, N,N-dimethylethanolamine and choline (N,N,N-trimethylethanolamine) as substrates for growth methanogenesis. The optimal temperature 30 °C;...
A thermophilic, non-spore-forming, marine, sulfate-reducing bacterium, strain SL6T, was isolated from deep-sea hydrothermal sulfides collected at Guaymas Basin. The gram-negative-staining cells occurred singly or in pairs as small, highly motile rods. temperature range for growth 50-80 degrees C with an optimum 75 C. pH 70 6.3-6.8, 6.5. NaCl concentration 5-55 g l(-1), 30 l(-1). H2 and CO2 were the only substrates sulfate reduction. However, stimulated by several organic compounds. Sulfur,...
A novel, strictly anaerobic, thermophilic sulfur-reducing bacterium, strain 525T, was isolated from tubes of the deep-sea hydrothermal vent polychaete Alvinella pompejana, collected on East Pacific Rise (13 degrees N). This organism grew in temperature range 37-68 C, optimum being 53 and pH 6.4-7.4, 6.8-7.0. The NaCl for growth 0.8-5.0%, 3.0%. Strain 525T lithoautotrophically with H2 as energy source, S0 electron acceptor CO2 carbon source. Alternatively, able to use formate an G+C content...
Two strains of thermophilic, anaerobic, chemolithoautotrophic bacteria, designated JRT and DR, were isolated from hydrothermal samples collected on the Mid-Atlantic Ridge Rainbow (36° 16′ N, 33° 54′ W) Menez Gwen (37° 50′ 31° vent fields, respectively. Cells both isolates short, straight- to vibrio-shaped, motile rods with one polar flagellum, Gram-negative non-sporulating. Strain was characterized in detail. It found grow optimally at pH 6·5–6·7, 60 °C presence 30 g NaCl l−1. could use...
A novel moderately thermophilic, organotrophic, microaerophilic, facultatively chemolithotrophic bacterium, designated strain 506T, was isolated from a deep-sea hydrothermal vent site at 13°N in the East Pacific Rise. Cells were Gram-negative, non-motile rods. The organism grew temperature range 40–68 °C, with an optimum 60 and pH 5·5–8·4, around 7·5. NaCl concentration for growth 10–50 g l−1, 30 l−1. Strain 506T chemoorganoheterotrophically carbohydrates, proteinaceous substrates, organic...
Three thermophilic, anaerobic, strictly chemolithoautotrophic, sulphur- and/or thiosulphate-reducing bacteria, designated SL17 T , SL19 and SL22 were isolated from deep-sea hydrothermal samples collected at 13 °N (East Pacific Rise), Guaymas Basin (Gulf of California) 23 (Mid-Atlantic Ridge), respectively. These strains differed in their morphology, temperature range optimum for growth, energy substrates 16S rRNA gene sequences. The G+C content the genomic DNA was 41 mol% (SL22 ), 42 (SL17 )...
Summary Submarine mud volcanoes are a significant source of methane to the atmosphere. The Napoli volcano, situated in brine‐impacted Olimpi Area Eastern Mediterranean Sea, emits mainly biogenic particularly at centre volcano. Temperature gradients support suggestion that is cold volcano with moderate fluid flow rates. Biogeochemical and molecular genetic analyses were carried out assess methanogenic activity rates, pathways diversity hypersaline sediments Methylotrophic methanogenesis was...
A novel anaerobic, moderately thermophilic, spore-forming bacterium, designated strain BRT, was isolated from deep-sea hydrothermal core samples collected at the Rainbow vent field on Mid-Atlantic Ridge (36 degrees 14' N 33 54' W). The cells were found to be rod-shaped, non-motile, Gram-positive and spore-forming. organism grew in temperature range 37-60 C, with an optimum 55 pH values 6-8.5, around 7. NaCl concentrations for growth 10-40 g l(-1), 20-30 l(-1). Strain BRT...