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| Registros recuperados: 41 | |
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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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| Bellec, Laure; Cambon Bonavita, Marie-anne; Hourdez, Stéphane; Jebbar, Mohamed; Tasiemski, Aurélie; Durand, Lucile; Gayet, Nicolas; Zeppilli, Daniela. |
| Prokaryotes and free-living nematodes are both very abundant and co-occur in marine environments, but little is known about their possible association. Our objective was to characterize the microbiome of a neglected but ecologically important group of free-living benthic nematodes of the Oncholaimidae family. We used a multi-approach study based on microscopic observations (Scanning Electron Microscopy and Fluorescence In Situ Hybridization) coupled with an assessment of molecular diversity using metabarcoding based on the 16S rRNA gene. All investigated free-living marine nematode specimens harboured distinct microbial communities (from the surrounding water and sediment and through the seasons) with ectosymbiosis seemed more abundant during summer.... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00494/60614/64098.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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| 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 |
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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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| 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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| L'Haridon, Stephane; Corre, Erwan; Guan, Yue; Vinu, Manikandan; La Cono, Violetta; Yakimov, Michail; Stingl, Ulrich; Toffin, Laurent; Jebbar, Mohamed. |
| We report here the complete genome sequence (2.08 Mb) of Methanohalophilus portucalensis strain FDF-1T, a halophilic methylotrophic methanogen isolated from the sediment of a saltern in Figeria da Foz, Portugal. The average nucleotide identity and DNA-DNA hybridization analyses show that Methanohalophilus mahii, M. halophilus, and M. portucalensis are three different species within the Methanosarcinaceae family. |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00420/53138/54102.pdf |
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| 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 |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00031/14185/11865.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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| 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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| 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 |
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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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| 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 |
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| 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 |
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| Thiel, Axel; Michoud, Gregoire; Moalic, Yann; Flament, Didier; Jebbar, Mohamed. |
| In this study, we developed a gene disruption system for Thermococcus barophilus using simvastatin for positive selection and 5-fluoroorotic acid (5-FOA) for negative selection or counterselection to obtain markerless deletion mutants using single-and double-crossover events. Disruption plasmids carrying flanking regions of each targeted gene were constructed and introduced by transformation into wild-type T. barophilus MP cells. Initially, a pyrF deletion mutant was obtained as a starting point for the construction of further markerless mutants. A deletion of the hisB gene was also constructed in the UBOCC-3256 (Delta pyrF) background, generating a strain (UBOCC-3260) that was auxotrophic for histidine. A functional pyrF or hisB allele from T. barophilus... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00187/29818/28263.pdf |
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| Registros recuperados: 41 | |
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