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| Registros recuperados: 38 | |
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| Ribeiro,Catherine Gérikas; Steffens,Maria Berenice Reynaud; Etto,Rafael Mazer; Galvão,Carolina Weigert; Martins,César de Castro; Pedrosa,Fábio de Oliveira; Kolm,Hedda Elisabeth. |
| The mangrove's sediments from the coastal areas under human activities may contain significant contaminations by hydrocarbons, even when there are no visual evidences of it. The microorganisms are essential to these ecosystems, especially in the control of their chemical environment. Sediment samples were collected in two regions under different environment conditions (pristine and contaminated) of the Paranaguá Estuarine Complex (Paranaguá Bay and Laranjeiras Bay), Brazil. Aliphatic hydrocarbons were determined by the GC-FID to assess the status of contamination of the studied areas. The total DNA was extracted from these samples. The 16S rRNA gene was amplified by the PCR reactions with the pair of primers 21F and 958R for the archaeal domain, and 27F... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Diversity; Mangroves; Archaea; Bacteria; 16S rRNA; ARDRA; Aliphatic hydrocarbons. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132013000200013 |
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| Hong,Sung-Jun; Park,Chang Eon; Park,Gun-Seok; Kim,Min-Chul; Jung,Byung Kwon; Shin,Jae-Ho. |
| Abstract Thermococcus thioreducens DSM 14981T, a sulfur-reducing archaeon, was isolated from the rainbow hydrothermal vent site on the Mid-Atlantic Ridge. Herein, we report the draft genome sequence of T. thioreducens DSM 14981T; we obtained 41 contigs with a genome size of 2,052,483 bp and G + C content of 53.5%. This genome sequence will not only help understand how the archaeon adapts to the deep-sea hydrothermal environment but also aid the development of enzymes that are highly stable under extreme conditions for industrial applications. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Archaea; Hyperthermophile; Thermococcus thioreducens. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822017000100003 |
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| Alquéres,S.M.C.; Almeida,R.V.; Clementino,M.M.; Vieira,R.P.; Almeida,W.I.; Cardoso,A.M.; Martins,O.B.. |
| Archaea represent a considerable fraction of the prokaryotic world in marine and terrestrial ecosystems, indicating that organisms from this domain might have a large impact on global energy cycles. The extremophilic nature of many archaea has stimulated intense efforts to understand the physiological adaptations for living in extreme environments. Their unusual properties make them a potentially valuable resource in the development of novel biotechnological processes and industrial applications as new pharmaceuticals, cosmetics, nutritional supplements, molecular probes, enzymes, and fine chemicals. In the present mini-review, we show and discuss some exclusive characteristics of Archaea domain and the current knowledge about the biotechnological uses of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Archaea; Biotechnology; Extremozymes; Genomic; Molecular Phylogeny. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822007000300002 |
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| Santana,Priscila Bessa; Ghilardi Junior,Rubens; Alves,Claudio Nahum; Silva,Jeronimo Lameira; McCulloch,John Anthony; Schneider,Maria Paula Cruz; Silva,Artur da Costa da. |
| Methanogenic archaeans are organisms of considerable ecological and biotechnological interest that produce methane through a restricted metabolic pathway, which culminates in the reaction catalyzed by the Methyl-coenzyme M reductase (Mcr) enzyme, and results in the release of methane. Using a metagenomic approach, the gene of the a subunit of mcr (mcrα) was isolated from sediment sample from an anoxic zone, rich in decomposing organic material, obtained from the Tucuruí hydroelectric dam reservoir in eastern Brazilian Amazonia. The partial nucleotide sequences obtained were 83 to 95% similar to those available in databases, indicating a low diversity of archaeans in the reservoir. Two orders were identified -the Methanomicrobiales, and a unique Operational... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazonian; Archaea; Diversity; Methyl-coenzyme M reductase; Mcrα; Homology modeling. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000100018 |
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| Omoregie, Enoma O.; Niemann, Helge; Mastalerz, Vincent; De Lange, Gert J.; Stadnitskaia, Alina; Mascle, Jean; Foucher, Jean-paul; Boetius, Antje. |
| The Eastern Mediterranean hosts a variety of active cold seep systems, such as gas chimneys, mud volcanoes and pockmarks, in water depths of 500 to 3200 m. As part of the NAUTINIL expedition in 2003, the sediments of cold seeps on the Nile Deep Sea Fan (NDSF) were sampled for the first time for biogeochemical and microbiological analyses. Here we compare rates of the anaerobic oxidation of methane (AOM) and sulfate reduction (SR) as well as the microbial community structure of a variety of cold seep systems including mud volcanoes, pockmarks and brine seeps. Our results revealed strong differences in microbial activity among the different seep systems of the Eastern, Central and Western provinces of the NDSF, as well as the Olimpi field (Central... |
| Tipo: Text |
Palavras-chave: Methane oxidation; Sulfate reduction; Archaea; Cold seeps; Mud volcano; Pockmarks; Nile Deep Sea Fan. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11087/7910.pdf |
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| Hogrel, Gaelle; Lu, Yang; Alexandre, Nicolas; Bossé, Audrey; Dulermo, Remi; Ishino, Sonoko; Ishino, Yoshizumi; Flament, Didier. |
| Among the three domains of life, the process of homologous recombination (HR) plays a central role in the repair of double-strand DNA breaks and the restart of stalled replication forks. Curiously, main protein actors involved in the HR process appear to be essential for hyperthermophilic Archaea raising interesting questions about the role of HR in replication and repair strategies of those Archaea living in extreme conditions. One key actor of this process is the recombinase RadA, which allows the homologous strand search and provides a DNA substrate required for following DNA synthesis and restoring genetic information. DNA polymerase operation after the strand exchange step is unclear in Archaea. Working with Pyrococcus abyssi proteins, here we show... |
| Tipo: Text |
Palavras-chave: Homologous recombination; Archaea; DNA polymerase; Recombinase; DNA repair. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00641/75274/75539.pdf |
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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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| Killelea, Tom; Ralec, Celine; Bosse, Audrey; Henneke, Ghislaine. |
| DNA polymerases are versatile tools used in numerous important molecular biological core technologies like the ubiquitous polymerase chain reaction (PCR), cDNA cloning, genome sequencing, and nucleic acid based diagnostics. Taking into account the multiple DNA amplification techniques in use, different DNA polymerases must be optimized for each type of application. One of the current tendencies is to reengineer or to discover new DNA polymerases with increased performance and broadened substrate spectra. At present, there is a great demand for such enzymes in applications, e.g., forensics or paleogenomics. Current major limitations hinge on the inability of conventional PCR enzymes, such as Taq, to amplify degraded or low amounts of template DNA. Besides,... |
| Tipo: Text |
Palavras-chave: DNA polymerase; Archaea; Family D; PCR; Pyrococcus. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00193/30450/28871.pdf |
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| Gonthier, Isabelle; Rager, Marie-noëlle; Metzger, Pierre; Guezennec, Jean; Largeau, Claude. |
| The lipids of a deep-sea hydrothermal vent arch ae on, Thermococcus S 557, were isolated, purified and structurally determined. Based on acid methanolysis and spectroscopic studies, the polar lipids were shown to comprise diphytanyl glycerol and dibiphytanyl diglycerol, typical membrane lipids of Arch aea. From the neutral lipids, 2,3-di-O-dihydro-14,15-geranylgeranyl glycerol was isolated. This novel ether lipid is, very likely, a close intermediate in the biosynthesis of diphytanyl glycerol diether in Arch aea. |
| Tipo: Text |
Palavras-chave: Mass spectrometry; NMR; Novel glycerol diether lipid; Thermococcus sp; Archaea. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-736.pdf |
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| Roussel, Erwan; Konn, Cecile; Charlou, Jean-luc; Donval, Jean-pierre; Fouquet, Yves; Querellou, Joel; Prieur, Daniel; Cambon-bonavita, Marie-anne. |
| The distribution of Archaea and methanogenic, methanotrophic and sulfate-reducing communities in three Atlantic ultramafic-hosted hydrothermal systems (Rainbow, Ashadze, Lost City) was compared using 16S rRNA gene and functional gene (mcrA, pmoA and dsrA) clone libraries. The overall archaeal community was diverse and heterogeneously distributed between the hydrothermal sites and the types of samples analyzed (seawater, hydrothermal fluid, chimney and sediment). The Lost City hydrothermal field, characterized by high alkaline warm fluids (pH>11; T<95 °C), harbored a singular archaeal diversity mostly composed of unaffiliated Methanosarcinales. The archaeal communities associated with the recently discovered Ashadze 1 site, one of the deepest active... |
| Tipo: Text |
Palavras-chave: Archaea; Hydrothermal vent; Mid-Atlantic Ridge; 16S rRNA gene; Sediment; Ultramafic. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00067/17836/15573.pdf |
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| Roussel, Erwan; Sauvadet, Anne Laure; Allard, Jonathan; Chaduteau, Carine; Richard, Pierre; Cambon Bonavita, Marie-anne; Chaumillon, Eric. |
| In Marennes-Oleron Bay, a macro-tidal bay located on the French Atlantic coast, kilometer-scale acoustic turbidity reveals an accumulation of free gas in the sediment. Large concentrations of organic matter and rapid sedimentation rates provide ideal settings for biogenic methane cycling. We integrate seismic, sedimentologic, biogeochemical and molecular genetic approaches to determine whether microbial methane cycling is involved in this process. Here we show that the acoustic turbidity upper boundary matched with X-ray facies displaying fissures with the highest methane concentrations, demonstrating the existence of methane bubbles in the sediment. 16S rRNA and mcrA gene clone libraries were dominated by sequences affiliated to the three known ANME... |
| Tipo: Text |
Palavras-chave: Sediment; Methane; McrA; 16S rRNA; Archaea. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6165.pdf |
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| Henneke, Ghislaine; Gueguen, Yannick; Flament, Didier; Azam, Philippe; Querellou, Joel; Dietrich, Jacques; Hubscher, Ulrich; Raffin, Jean-paul. |
| The molecular organization of the replication complex in archaea is similar to that in eukaryotes. Only two proteins homologous to subunits of eukaryotic replication factor C (RFC) have been detected in Pyrococcus abyssi (Pab). The genes encoding these two proteins are arranged in tandem. We cloned these two genes and co-expressed the corresponding recombinant proteins in Escherichia coli. Two inteins present in the gene encoding the small subunit (Pab RFC-small) were removed during cloning. The recombinant protein complex was purified by anion-exchange and hydroxyapatite chromatography. Also, the Pab RFC-small subunit could be purified, while the large subunit (Pab RFC-large) alone was completely insoluble. The highly purified Pab RFC complex possessed an... |
| Tipo: Text |
Palavras-chave: PCNA binding domain; Pyrococcus abyssi; Hyperthermophile; Archaea; Replication factor C. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/2002/publication-675.pdf |
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| Rouillon, Christophe; Henneke, Ghislaine; Flament, Didier; Querellou, Joel; Raffin, Jean-paul. |
| DNA replication in Archaea, as in other organisms, involves large protein complexes called replisomes. In the Euryarchaeota subdomain, only two putative replicases have been identified, and their roles in leading and lagging strand DNA synthesis are still poorly understood. In this study, we focused on the coupling of proliferating cell nuclear antigen (PCNA)loading mechanisms with DNA polymerase function in the Euryarchaea Pyrococcus abyssi. PCNA spontaneously loaded onto primed DNA, and replication factor C dramatically increased this loading. Surprisingly, the family B DNA polymerase (Pol B) also increased PCNA loading, probably by stabilizing the clamp on primed DNA via an essential motif. In contrast, on an RNA-primed DNA template, the PCNA/Pol B... |
| Tipo: Text |
Palavras-chave: RF C; PCNA loading; DNA polymerase switching; DNA replication; Archaea. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2638.pdf |
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| Lemor, Melanie; Kong, Ziqing; Henry, Etienne; Brizard, Raphael; Laurent, Sebastien; Bosse, Audrey; Henneke, Ghislaine. |
| Consistent with the fact that ribonucleotides (rNTPs) are in excess over deoxyribonucleotides (dNTPs) in vivo, recent findings indicate that replicative DNA polymerases (DNA Pols) are able to insert ribonucleotides (rNMPs) during DNA synthesis, raising crucial questions about the fidelity of DNA replication in both Bacteria and Eukarya. Here, we report that the level of rNTPs is 20-fold higher than that of dNTPs in Pyrococcus abyssi cells. Using dNTP and rNTP concentrations present in vivo, we recorded rNMP incorporation in a template-specific manner during in vitro synthesis, with the family-D DNA Pol (PolD) having the highest propensity compared with the family-B DNA Pol and the p41/p46 complex. We also showed that ribonucleotides accumulate at a... |
| Tipo: Text |
Palavras-chave: Archaea; DNA replication and repair; DNA polymerase; Nucleotide pool; Translesion synthesis. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00464/57603/59796.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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| Hugoni, Mylene; Escalas, Arthur; Bernard, Cecile; Nicolas, Sebastien; Jezequel, Didier; Vazzoler, Fanny; Sarazin, Gerard; Leboulanger, Christophe; Bouvy, Marc; Got, Patrice; Ader, Magali; Troussellier, Marc; Agogue, Helene. |
| Thalassohaline ecosystems are hypersaline environments originating from seawater in which sodium chloride is the most abundant salt and the pH is alkaline. Studies focusing on microbial diversity in thalassohaline lakes are still scarce compared with those on athalassohaline lakes such as soda lakes that have no marine origin. In this work, we investigated multiple facets of bacterial, archaeal and eukaryotic diversity in the thalassohaline Lake Dziani Dzaha using a metabarcoding approach. We showed that bacterial and archaeal diversity were mainly affected by contrasting physicochemical conditions retrieved at different depths. While photosynthetic microorganisms were dominant in surface layers, chemotrophic phyla (Firmicutes or Bacteroidetes) and... |
| Tipo: Text |
Palavras-chave: Archaea; Bacteria; Eukaryotes; Extreme environment; Metabarcoding; Thalassohaline lake. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00464/57564/59738.pdf |
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| Registros recuperados: 38 | |
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