|
|
|
| Registros recuperados: 41 | |
|
|
| Vannier, Pauline; Marteinsson, Viggo Thor; Fridjonsson, Olafur Hedinn; Oger, Philippe; Jebbar, Mohamed. |
| Thermococcus barophilus is a hyperthermophilic, anaerobic, mixed heterotrophic, and carboxydotrophic euryarchaeon isolated from the deep sea hydrothermal vent Snakepit site on the mid-Atlantic ridge at a depth of 3,550 m. T. barophilus is the first true piezophilic, hyperthermophilic archaeon isolated, having an optimal growth at 40 MPa. Here we report the complete genome sequence of strain MP, the type strain of T. barophilus. The genome data reveal a close proximity with Thermococcus sibiricus, another Thermococcus isolated from the deep biosphere and a possible connection to life in the depths. |
| Tipo: Text |
|
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00031/14185/11865.pdf |
| |
|
|
| Alain, Karine; Callac, Nolwenn; Ciobanu, Maria Cristina; Reynaud, Yann; Duthoit, Frederique; Jebbar, Mohamed. |
| Extracting DNA from deep subsurface sediments is challenging given the complexity of sediments types, low bio-masses, resting structures (spores, cysts) frequently encountered in deep sediments, and the potential presence of enzymatic inhibitors. Promising results for cell lysis efficiency were recently obtained by use of a cryogenic mill (Lipp et al., 2008). These findings encouraged us to devise a DNA extraction protocol using this tool. Thirteen procedures involving a combination of grinding in liquid nitrogen (for various durations and beating rates) with different chemical solutions (phenol, chloroform, SDS, sarkosyl, proteinase, GTC), or with use of DNA recovery kits (MagExtractor (R)) were compared. Effective DNA extraction was evaluated in terms of... |
| Tipo: Text |
Palavras-chave: Sediment; DNA extraction; Deep subsurface biosphere. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00056/16691/14364.pdf |
| |
|
|
| Oger, Philippe M.; Jebbar, Mohamed. |
| The current paper reviews strategies employed by microorganisms from the deep biosphere, especially piezophiles (from the greek piezo = to press and philo = love), to cope with high hydrostatic pressure (HHP) prevailing in these biotopes. The aim of this review is not to constitute an exhaustive report of our current knowledge on the physiology of piezophiles, as recent reviews have covered part of this subject in detail (Abe, 2007; Lauro and Bartlett, 2008; Michiels et al., 2008; Simonato et al., 2006). Rather, we illustrate here, via a few chosen examples, where we stand in our understanding of the mechanisms employed by microorganisms from the depths of our planet to cope with HHP. (C) 2010 Institut Pasteur. Published by Elsevier Masson SAS. All rights... |
| Tipo: Text |
Palavras-chave: Adaptation and evolution; Archaea; Deep biosphere; High hydrostatic pressure; Piezophile; Stress response. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00027/13797/11043.pdf |
| |
|
|
| Golub, Maksym; Martinez, Nicolas; Michoud, Gregoire; Ollivier, Jacques; Jebbar, Mohamed; Oger, Philippe; Peters, Judith. |
| In live cells, high concentrations up to 300–400 mg/mL, as in Eschericia coli (Ellis, R. J. Curr. Opin. Struct. Biol. 2001, 11, 114) are achieved which have effects on their proper functioning. However, in many experiments only individual parts of the cells as proteins or membranes are studied in order to get insight into these specific components and to avoid the high complexity of whole cells, neglecting by the way the influence of crowding. In the present study, we investigated cells of the order of Thermococcales, which are known to live under extreme conditions, in their intact form and after cell lysis to extract the effect of crowding on the molecular dynamics of the proteome and of water molecules. We found that some parameters characterizing the... |
| Tipo: Text |
|
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00454/56526/58329.pdf |
| |
|
|
| Jun, Xu; Liu Lupeng,; Xu Minjuan,; Oger, Philippe; Wang Fengping,; Jebbar, Mohamed; Xiang, Xiao. |
| Pyrococcus yayanosii CH1 is the first obligate piezophilic hyperthermophilic archaeon isolated from the deep-sea hydrothermal site Ashadze on the mid-Atlantic ridge at a depth of 4,100 m. This organism grows within a temperature range of 80 to 108 degrees C and a hydrostatic pressure range of 20 to 120 MPa, with optima at 98 degrees C and 52 MPa, respectively. Here, we report the complete genome sequence (1,716,817 bp, with a G+C content of 51.6%) of the type strain P. yayanosii CH1(T) (= JCM 16557). This genomic information reveals a systematic view of the piezoadaptation strategy and evolution scenario of metabolic pathways in Thermococcales. |
| Tipo: Text |
|
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00041/15247/12621.pdf |
| |
|
|
| Michoud, Gregoire; Jebbar, Mohamed. |
| Pyrococcus yayanosii CH1, as the first and only obligate piezophilic hyperthermophilic microorganism discovered to date, extends the physical and chemical limits of life on Earth. It was isolated from the Ashadze hydrothermal vent at 4,100 m depth. Multi-omics analyses were performed to study the mechanisms used by the cell to cope with high hydrostatic pressure variations. In silico analyses showed that the P. yayanosii genome is highly adapted to its harsh environment, with a loss of aromatic amino acid biosynthesis pathways and the high constitutive expression of the energy metabolism compared with other non-obligate piezophilic Pyrococcus species. Differential proteomics and transcriptomics analyses identified key hydrostatic pressure-responsive genes... |
| Tipo: Text |
|
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00342/45295/44756.pdf |
| |
|
|
| Gaboyer, Frederic; Vandenabeele-trambouze, Odile; Cao, Junwei; Ciobanu, Maria-cristina; Jebbar, Mohamed; Le Romancer, Marc; Alain, Karine. |
| A novel halophilic bacterium, strain RHS90T, was isolated from marine sediments from the Gulf of Lions, in the Mediterranean Sea. Its metabolic and physiological characteristics were examined under various cultural conditions, including exposure to stressful ones (oligotrophy, high pressure and high concentrations of metals). Based on phylogenetic analysis of the 16S rRNA gene, the strain was found to belong to the genus Halomonas in the class Gammaproteobacteria. Its closest relatives are H. axialensis and H. meridiana (98% similarity). DNA-DNA hybridizations indicated that the novel isolate is genotypically distinct from these species. The DNA G+C content of the strain is 54.4 mol%. The main fatty acids (C18:1ω7c, 2-OH iso-C15:0, C16:0 and/or C19:0 cyclo... |
| Tipo: Text |
Palavras-chave: Halomonas; Taxonomy; Environmental adaptation; Metal tolerance; Poly-beta-hydroxyalkanoate; Compatible. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00201/31253/29658.pdf |
| |
|
|
| Zeng, Xiang; Jebbar, Mohamed; Shao, Zongze. |
| We report the genome sequence of Palaeococcus pacificus DY20341(T), isolated from a sediment sample collected from eastern Pacific Ocean hydrothermal fields, which is the first report of a complete genome for a Palaeococcus species. The genome sequence will help to better understand differentiation phylogenetic relationships and evolution of several Thermococcales species. |
| Tipo: Text |
|
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00601/71312/69741.pdf |
| |
|
|
| Alcaide, Maria; Tchigvintsev, Anatoli; Martinez-martinez, Monica; Popovic, Ana; Reva, Oleg N.; Lafraya, Alvaro; Bargiela, Rafael; Nechitaylo, Taras Y.; Matesanz, Ruth; Cambon-bonavita, Marie-anne; Jebbar, Mohamed; Yakimov, Michail M.; Savchenko, Alexei; Golyshina, Olga V.; Yakunin, Alexander F.; Golyshin, Peter N.; Ferrer, Manuel. |
| The shrimp Rimicaris exoculata dominates the fauna in deep-sea hydrothermal vent sites along the Mid-Atlantic Ridge (depth, 2,320 m). Here, we identified and biochemically characterized three carboxyl esterases from microbial communities inhabiting the R. exoculata gill that were isolated by naive screens of a gill chamber metagenomic library. These proteins exhibit low to moderate identity to known esterase sequences (<= 52%) and to each other (11.9 to 63.7%) and appear to have originated from unknown species or from genera of Proteobacteria related to Thiothrix/Leucothrix (MGS-RG1/RG2) and to the Rhodobacteraceae group (MGS-RG3). A library of 131 esters and 31 additional esterase/lipase preparations was used to evaluate the activity profiles of these... |
| Tipo: Text |
|
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00256/36721/36438.pdf |
| |
|
|
| Cao, Junwei; Birien, Tiphaine; Gayet, Nicolas; Huang, Zhaobin; Shao, Zongze; Jebbar, Mohamed; Alain, Karine. |
| A novel sulfur-reducing bacterium, strain K6013(T), was isolated from a sulfide sample collected at a depth of 2771 m from a high-temperature hydrothermal vent in the Indian Ocean. Cells were Gram-stain-negative, anaerobic, motile rods (0.92.2 x 0.4-0.6 mu m). The strain grew at NaCl concentrations ranging from 1 to 4.5% (w/v) (optimum 2.5 %), at pH 5 to 8 (optimum pH 6), and at temperatures between 40 and 75 degrees C (optimum 65 degrees C). K6013(T) was an obligate chemolithoautotroph, using thiosulfate, sulfur and nitrate as terminal electron acceptors in the presence of H-2 but not sulfate, sulfite nor nitrite. The major cellular fatty acids were C-16 : 0 (17.4 %), C-18 : 1 omega 7c/C-18 : 1 omega 6c (ummed feature 8, 37.91 %), C-18 : 0 (18.29 %) and... |
| Tipo: Text |
Palavras-chave: Desulfurobacterium; Thermophilic; Hydrothermal vent; Chemolithoautotroph; Sulfur-reducer. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00395/50637/53724.pdf |
| |
|
|
| Cao, Junwei; Gayet, Nicolas; Zeng, Xiang; Shao, Zongze; Jebbar, Mohamed; Alain, Karine. |
| A novel sulfate-reducing bacterium, strain J2(T), was isolated from a serpentinized peridotite sample from the Indian Ocean. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain J2(T) clustered with the genus Desulfovibrio within the family Desulfovibrionaceae, but it showed low similarity (87.95 %) to the type species Desulfovibrio desulfuricans DSM 642(T). It was most closely related to Desulfovibrio portus MSL79(T) (96.96 %), followed by Desulfovibrio aespoeensis Aspo-2(T) (96.11 %), Desulfovibrio piezophilus C1TLV30(T) (96.04 %) and Desulfovibrio profundus DSM 11384(T) (95.17 %). Other available sequences shared less than 93.33 % 16S rRNA gene sequence similarity. Cells were Gram-staining-negative, anaerobic, motile vibrios (2-6 x... |
| Tipo: Text |
|
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00359/47018/47131.pdf |
| |
|
|
| Boyen, Catherine; Jaouen, Pascal; Blanchard, Gilbert; Compere, Chantal; Dufour, Alain; Durand, Patrick; Guerard, Fabienne; Hallouin, Florence; Jebbar, Mohamed; Le Blay, Gwenaelle; Le Deit, Hervé; Le Seyec, Jocelyne; Monks, Brian; Portal-sellin, Rachel; Probert, Ian; Pruvost, Jeremy. |
| Marine (= blue) biotechnology, i.e. the utilization of marine bio-resources as a target or source of biotechnological applications, is a field with massive potential for innovation and economic growth. In a context of rapid climate change and increasing pressure on natural resources, renewed interest in marine biotechnology has been promoted by application of recent methodological and technological advances, notably in bioprocessing and in the various –omics domains, to the study of marine biodiversity. Marine biological resources potentially represent a sustainable raw material for exploitation in diverse fields, including nutrition, health, agriculture, aquaculture, energy, environment, and cosmetics. Marine biotechnology is now recognized as a... |
| Tipo: Text |
|
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00273/38460/36860.pdf |
| |
|
|
| Jiang, Lijing; L'Haridon, Stephane; Jebbar, Mohamed; Xu, Hongxiu; Alain, Karine; Shao, Zongze. |
| Kosmotoga pacifica strain SLHLJ1T is a thermophilic chemoorganoheterotrophic bacterium isolated from a deep-sea hydrothermal sediment. It belongs to the physiologically homogeneous Thermotogaceae family. Here, we describe the phenotypic features of K. pacifica together with its genome sequence and annotation. The chromosome has 2,169,170 bp, organized in one contig. A total of 1897 candidate protein-encoding genes and 177 RNA genes were identified. The 16S rRNA gene sequence of this strain is distantly related to sequences of some relatives classified in the same genus (K. olearia 7.02% and K. shengliensis 7.83%), with dissimilarity percentages close to the threshold generally described for genus delineation. Nevertheless, the percentage of conserved... |
| Tipo: Text |
Palavras-chave: Marine; Hydrothermal vent; Thermotogales; Chemoorganoheterotroph; Thermophile. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00371/48191/48324.pdf |
| |
|
|
| Slobodkin, Alexander; Slobodkina, Galina; Allioux, Maxime; Alain, Karine; Jebbar, Mohamed; Shadrin, Valerian; Kublanov, Ilya; Toshchakov, Stepan; Bonch-osmolovskaya, Elizaveta. |
| nformation on the biochemical pathways of carbon and energy metabolism in representatives of the deep lineage bacterial phylum Deferribacteres are scarce. Here, we report the results of the sequencing and analysis of the high-quality draft genome of the thermophilic chemolithoautotrophic anaerobe Deferribacter autotrophicus. Genomic data suggest that CO2 assimilation is carried out by recently proposed reversible tricarboxylic acid cycle (“roTCA cycle”). The predicted genomic ability of D. autotrophicus to grow due to the oxidation of carbon monoxide was experimentally proven. CO oxidation was coupled with the reduction of nitrate to ammonium. Utilization of CO most likely involves anaerobic [Ni, Fe]-containing CO dehydrogenase. This is the first evidence... |
| Tipo: Text |
Palavras-chave: Autotrophic; Thermophile; RoTCA cycle; CO oxidation; Fe(III)-reduction; Nitrate reduction. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00589/70078/68051.pdf |
| |
|
|
| Cario, Anais; Mizgier, Alex; Thiel, Axel; Jebbar, Mohamed; Oger, Phil M.. |
| Most Thermococcales accumulate di-myo-inositol-phosphate (DIP) as an organic solute as a response to heat stress. We have studied the accumulation of this osmolyte in the high-hydrostatic pressure adapted hyperthermophile Thermococcus barophilus. We found no accumulation of DIP under any of the stress conditions tested, although this archaeon harbors the 3 DIP synthesis genes. Lack of synthesis is due to the lack of expression of TERMP_01135 coding for the second step of DIP synthesis. In contrast to other species, the T. barophilus synthesis operon is interrupted by a four gene locus, in reverse orientation. Restoring an operon like structure at the DIP locus restored DIP synthesis, but did not have an impact on growth characteristics, suggesting that... |
| Tipo: Text |
Palavras-chave: High hydrostatic pressure; Heat stress; Di-myo-inositol-phosphate; Thermococcus barophilus. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00270/38113/37216.pdf |
| |
|
|
| Leis, Benedikt; Heinze, Simon; Angelov, Angel; Pham, Vu Thuy Trang; Thürmer, Andrea; Jebbar, Mohamed; Golyshin, Peter N.; Streit, Wolfgang R.; Daniel, Rolf; Liebl, Wolfgang. |
| Extreme habitats serve as a source of enzymes that are active under extreme conditions and are candidates for industrial applications. In this work, six large-insert mixed genomic libraries were screened for hydrolase activities in a broad temperature range (8–70°C). Among a variety of hydrolytic activities, one fosmid clone, derived from a library of pooled isolates of hyperthermophilic archaea from deep sea vents, displayed hydrolytic activity on carboxymethyl cellulose substrate plates at 70°C but not at lower temperatures. Sequence analysis of the fosmid insert revealed a gene encoding a novel glycoside hydrolase family 12 (GHF12) endo-1,4-β-glucanase, termed Cel12E. The enzyme shares 45% sequence identity with a protein from the archaeon Thermococcus... |
| Tipo: Text |
Palavras-chave: Functional screenings; Extreme thermostable protein; Archaeal endoglucanase; Enzymatic characterization. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00601/71319/69744.pdf |
| |
|
|
| Broy, Sebastian; Chen, Chiliang; Hoffmann, Tamara; Brock, Nelson L.; Nau-wagner, Gabriele; Jebbar, Mohamed; Smits, Sander H. J.; Dickschat, Jeroen S.; Bremer, Erhard. |
| Dimethylsulfoniopropionate (DMSP) is an abundant osmolyte and anti-stress compound produced primarily in marine ecosystems. After its release into the environment, microorganisms can exploit DMSP as a source of sulfur and carbon, or accumulate it as an osmoprotectant. However, import systems for this ecophysiologically important compatible solute, and its stress-protective properties for microorganisms that do not produce it are insufficiently understood. Here we address these questions using a well-characterized set of Bacillus subtilis mutants to chemically profile the influence of DMSP import on stress resistance, the osmostress-adaptive proline pool and on osmotically controlled gene expression. We included in this study the naturally occurring... |
| Tipo: Text |
|
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00242/35302/33910.pdf |
| |
|
|
| Ciobanu, Maria Cristina; Burgaud, Gaetan; Dufresne, Alexis; Breuker, Anja; Redou, Vanessa; Ben Maamar, Sarah; Gaboyer, Frederic; Vandenabeele-trambouze, Odile; Lipp, Julius Sebastian; Schippers, Axel; Vandenkoornhuyse, Philippe; Barbier, Georges; Jebbar, Mohamed; Godfroy, Anne; Alain, Karine. |
| The subsurface realm is colonized by microbial communities to depths of >1000 meters below the seafloor (m.b.sf.), but little is known about overall diversity and microbial distribution patterns at the most profound depths. Here we show that not only Bacteria and Archaea but also Eukarya occur at record depths in the subseafloor of the Canterbury Basin. Shifts in microbial community composition along a core of nearly 2 km reflect vertical taxa zonation influenced by sediment depth. Representatives of some microbial taxa were also cultivated using methods mimicking in situ conditions. These results suggest that diverse microorganisms persist down to 1922 m.b.sf. in the seafloor of the Canterbury Basin and extend the previously known depth limits of... |
| Tipo: Text |
Palavras-chave: Deep biosphere; Subsurface life; Eukaryote; Record depth. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00201/31243/29895.pdf |
| |
|
|
| Dalmasso, Cecile; Oger, Philippe; Selva, Gwendoline; Courtine, Damien; L'Haridon, Stephane; Garlaschelli, Alexandre; Roussel, Erwan; Miyazaki, Junichi; Reveillaud, Julie; Jebbar, Mohamed; Takai, Ken; Maignien, Lois; Alain, Karine. |
| A novel strictly anaerobic, hyperthermophilic archaeon, designated strain CDGST, was isolated from a deep-sea hydrothermal vent in the Cayman Trough at 4964 m water depth. The novel isolate is obligate anaerobe and grows chemoorganoheterotrophically with stimulation of growth by sulphur containing compounds. Its growth is optimal at 75 °C, pH 6.0 and under a pressure of 50 MPa. It possesses the broadest hydrostatic pressure range for growth that has ever been described for a microorganism. Its genomic DNA G + C content is 51.11 mol%. The novel isolate belongs to the genus Thermococcus. Phylogenetic analyses indicated that it is most closely related to Thermococcus barossii DSM17882T based on its 16S rRNA gene sequence, and to ‘Thermococcus onnurineus’ NA1... |
| Tipo: Text |
Palavras-chave: Thermococcus; Piezophile; Hydrothermal vent; Cayman Trough. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00348/45949/45655.pdf |
| |
|
| |
| Registros recuperados: 41 | |
|
|
|
