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| Registros recuperados: 41 | |
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| Zeng, Xiang; Birrien, Jean-louis; Fouquet, Yves; Cherkashov, Georgy; Jebbar, Mohamed; Querellou, Joel; Oger, Philippe; Cambon-bonavita, Marie-anne; Xiao, Xiang; Prieur, Daniel. |
| A novel hydrothermal site was discovered in March 2007, on the mid-Atlantic ridge during the cruise 'Serpentine'. At a depth of 4100 m, the site 'Ashadze' is the deepest vent field known so far. Smoker samples were collected with the ROV 'Victor 6000' and processed in the laboratory for the enrichment of anaerobic heterotrophic microorganisms under high-temperature and high-hydrostatic pressure conditions. Strain CH1 was successfully isolated and assigned to the genus Pyrococcus, within the Euryarchaeota lineage within the Archaea domain. This organism grows within a temperature range of 80 to 108 degrees C and a pressure range of 20 to 120 MPa, with optima for 98 degrees C and 52 MPa respectively. Pyrococcus CH1 represents the first obligate piezophilic... |
| Tipo: Text |
Palavras-chave: Thermococcales; Extremophile; Deep sea hydrothermal vent; High hydrostatic pressure; Archaea. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6812.pdf |
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| 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 |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00242/35302/33910.pdf |
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| Peters, Judith; Martinez, Nicolas; Michoud, Gregoire; Carlo, Anais; Franzetti, Bruno; Oger, Philippe; Jebbar, Mohamed. |
| The majority of the biosphere is a high pressure environment. Around 70% of the marine biosphere lies at depths below 1000 m, i.e. at pressures of 100 bars or higher. To survive in these environments, deep-biosphere organisms have adapted to life at high pressure. In vitro studies showed that the activity of certain proteins originating from deep-sea organisms is less affected by high pressure than that of enzymes from surface organisms [1-3]. However, the genetic and structural bases for this increased pressure resistance are still unknown. Elastic incoherent neutron scattering studies, which provide access to information about molecular dynamics, constitute a very promising approach to decipher the structural adaptation in proteins living under high... |
| Tipo: Text |
Palavras-chave: Neutron Scattering; Molecular Dynamics; High Pressure; Deep Sea Microbes. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00251/36186/34725.pdf |
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| 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 |
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| 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 |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00041/15247/12621.pdf |
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| Cario, Anaïs; Jebbar, Mohamed; Thiel, Axel; Kervarec, Nelly; Oger, Phil M.. |
| The accumulation of mannosyl-glycerate (MG), the salinity stress response osmolyte of Thermococcales, was investigated as a function of hydrostatic pressure in Thermococcus barophilus strain MP, a hyperthermophilic, piezophilic archaeon isolated from the Snake Pit site (MAR), which grows optimally at 40 MPa. Strain MP accumulated MG primarily in response to salinity stress, but in contrast to other Thermococcales, MG was also accumulated in response to thermal stress. MG accumulation peaked for combined stresses. The accumulation of MG was drastically increased under sub-optimal hydrostatic pressure conditions, demonstrating that low pressure is perceived as a stress in this piezophile, and that the proteome of T. barophilus is low-pressure sensitive. MG... |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00345/45570/45178.pdf |
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| Cao, Junwei; Maignien, Lois; Shao, Zongze; Alain, Karine; Jebbar, Mohamed. |
| The complete genome sequence of Desulfovibrio indicus J2(T), a member of the family Desulfovibrionaceae, consists of 3,966,573-bp in one contig and encodes 3,461 predicted genes, 5 noncoding RNAs, 3 rRNAs operons, and 52 tRNA-encoding genes. The genome is consistent with a heterotrophic, anaerobic lifestyle including the sulfate reduction pathway. |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00601/71311/69740.pdf |
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| Jan, Cyrielle; Petersen, Jillian M.; Werner, Johannes; Teeling, Hanno; Huang, Sixing; Gloeckner, Frank Oliver; Golyshina, Olga V.; Dubilier, Nicole; Golyshin, Peter N.; Jebbar, Mohamed; Cambon-bonavita, Marie-anne. |
| The gill chamber of deep-sea hydrothermal vent shrimp Rimicaris exoculata hosts a dense community of epibiotic bacteria dominated by filamentous Epsilonproteobacteria and Gammaproteobacteria. Using metagenomics on shrimp from the Rainbow hydrothermal vent field, we showed that both epibiont groups have the potential to grow autotrophically and oxidize reduced sulfur compounds or hydrogen with oxygen or nitrate. For carbon fixation, the Epsilonproteobacteria use the reductive tricarboxylic acid cycle, whereas the Gammaproteobacteria use the Calvin–Benson–Bassham cycle. Only the epsilonproteobacterial epibionts had the genes necessary for producing ammonium. This ability likely minimizes direct competition between epibionts and also broadens the spectrum of... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00177/28874/28622.pdf |
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| 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 |
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| 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 |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00342/45295/44756.pdf |
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| Birien, Tiphaine; Thiel, Axel; Henneke, Ghislaine; Flament, Didier; Moalic, Yann; Jebbar, Mohamed. |
| A gene disruption system for Thermococcus barophilus was developed using simvastatin (HMG-CoA reductase encoding gene) for positive selection and 5-Fluoroorotic acid (5-FOA), a pyrF gene for negative selection. Multiple gene mutants were constructed with this system, which offers the possibility of complementation in trans, but produces many false positives (<80%). To significantly reduce the rate of false positives, we used another counterselective marker, 6-methylpurine (6-MP), a toxic analog of adenine developed in Thermococcus kodakarensis, consistently correlated with the TK0664 gene (encoding a hypoxanthine-guanine phosphoribosyl-transferase). We thus replaced pyrF by TK0664 on our suicide vector and tested T. barophilus strain sensitivity to 6-MP... |
| Tipo: Text |
Palavras-chave: Archaea; Piezophiles; Hyperthermophiles; Genetics; Gene deletion; Deep sea; Hydrothermal vents. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00425/53679/54523.pdf |
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| L’haridon, Stéphane; Corre, Erwan; Guan, Yue; Vinu, Manikandan; La Cono, Violetta; Yakimov, Mickail; Stingl, Ulrich; Toffin, Laurent; Jebbar, Mohamed. |
| The complete genome sequence of Methanohalophilus halophilus DSM 3094T, a member of the Methanosarcinaceae family and the Methanosarcianales order, consists of 2,022,959 bp in one contig and contains 2,137 predicted genes. The genome is consistent with a halophilic methylotrophic anaerobic lifestyle, including the methylotrophic and CO2-H2 methanogensis pathways. |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00372/48351/48523.pdf |
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| 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 |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00601/71312/69741.pdf |
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| 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 |
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| 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 |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00273/38460/36860.pdf |
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| L'Haridon, Stephane; Jiang, Lijing; Alain, Karine; Chalopin, Morgane; Rouxel, Ouafae; Beauverger, Mikael; Xu, Hongxiu; Shao, Zongze; Jebbar, Mohamed. |
| A novel strictly anaerobic thermophilic heterotrophic bacterium, strain SLHLJ1T, was isolated from a Pacific hydrothermal sediment. Cells were Gram-negative coccobacilli (approximately 1.0 × 0.6 μm) with a toga. It grew at temperatures between 33 and 78 °C (optimum 70 °C). Elemental sulphur and l-cystine stimulated its growth. It contained C16:0, C16:1 ω11c, C18:0 and C18:1 ω9c as major fatty acids (>5 %), 3 phospholipids and 2 glycolipids as polar lipids. Its DNA G+C content was 43.7 mol%. Phylogenetic analyses based on 16S rRNA gene sequences placed strain SLHLJ1T within the family Thermotogaceae. The novel isolate was most closely related to Kosmotoga arenicorallina (97.93 % 16S rRNA gene sequence similarity), K. olearia (92.43 %) and K. shengliensis... |
| Tipo: Text |
Palavras-chave: Thermotogales; Kosmotoga; Kosmotoga pacifica; Hydrothermal sediment. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00171/28204/26509.pdf |
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| Allioux, Maxime; Yvenou, Steven; Slobodkina, Galina; Slobodkin, Alexander; Shao, Zongze; Jebbar, Mohamed; Alain, Karine. |
| Marine hydrothermal systems are characterized by a pronounced biogeochemical sulfur cycle with the participation of sulfur-oxidizing, sulfate-reducing and sulfur-disproportionating microorganisms. The diversity and metabolism of sulfur disproportionators are studied to a much lesser extent compared with other microbial groups. Dissulfurirhabdus thermomarina SH388T is an anaerobic thermophilic bacterium isolated from a shallow sea hydrothermal vent. D. thermomarina is an obligate chemolithoautotroph able to grow by the disproportionation of sulfite and elemental sulfur. Here, we present the results of the sequencing and analysis of the high-quality draft genome of strain SH388T. The genome consists of a one circular chromosome of 2,461,642 base pairs, has a... |
| Tipo: Text |
Palavras-chave: Genome annotation; Dissulfurirhabdus; Shallow sea hydrothermal vents; Inorganic sulfur compound disproportionation. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00651/76270/77245.pdf |
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| Zapata-perez, Ruben; Garcia-saura, Antonio G.; Jebbar, Mohamed; Golyshin, Peter N.; Sanchez-ferrer, Alvaro. |
| Nicotinamidases catalyze the hydrolysis of the amide bond in nicotinamide (NAM) to produce ammonia and nicotinic acid (NA). These enzymes are an essential component of the NAD(+) salvage pathway and are implicated in the viability of several pathogenic organisms. Its absence in humans makes them a promising drug target. In addition, although they are key analytical biocatalysts for screening modulators in relevant biomedical enzymes, such as sirtuins and poly-ADP-ribosyltransferases, no commercial sources are available. Surprisingly, the finding of an affordable source of nicotinamidase from metagenomic libraries is hindered by the absence of a suitable and fast screening method. In this manuscript, we describe the development of two new whole-cell methods... |
| Tipo: Text |
Palavras-chave: Amidohydrolases; Nicotinamidase; Functional screening; Metagenome; Library; High-throughput screening assays. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00362/47269/47232.pdf |
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| Registros recuperados: 41 | |
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