Base de dados : MEDLINE
Pesquisa : B02.075.200 [Categoria DeCS]
Referências encontradas : 6 [refinar]
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  1 / 6 MEDLINE  
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[PMID]:25142282
[Au] Autor:Xie W; Zhang CL; Wang J; Chen Y; Zhu Y; de la Torre JR; Dong H; Hartnett HE; Hedlund BP; Klotz MG
[Ad] Endereço:State Key Laboratory of Marine Geology, Tongji University, Shanghai, 200092, China; Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA.
[Ti] Título:Distribution of ether lipids and composition of the archaeal community in terrestrial geothermal springs: impact of environmental variables.
[So] Source:Environ Microbiol;17(5):1600-14, 2015 May.
[Is] ISSN:1462-2920
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Archaea can respond to changes in the environment by altering the composition of their membrane lipids, for example, by modification of the abundance and composition of glycerol dialkyl glycerol tetraethers (GDGTs). Here, we investigated the abundance and proportions of polar GDGTs (P-GDGTs) and core GDGTs (C-GDGTs) sampled in different seasons from Tengchong hot springs (Yunnan, China), which encompassed a pH range of 2.5-10.1 and a temperature range of 43.7-93.6°C. The phylogenetic composition of the archaeal community (reanalysed from published work) divided the Archaea in spring sediment samples into three major groups that corresponded with spring pH: acidic, circumneutral and alkaline. Cluster analysis showed correlation between spring pH and the composition of P- and C-GDGTs and archaeal 16S rRNA genes, indicating an intimate link between resident Archaea and the distribution of P- and C-GDGTs in Tengchong hot springs. The distribution of GDGTs in Tengchong springs was also significantly affected by temperature; however, the relationship was weaker than with pH. Analysis of published datasets including samples from Tibet, Yellowstone and the US Great Basin hot springs revealed a similar relationship between pH and GDGT content. Specifically, low pH springs had higher concentrations of GDGTs with high numbers of cyclopentyl rings than neutral and alkaline springs, which is consistent with the predominance of high cyclopentyl ring-characterized Sulfolobales and Thermoplasmatales present in some of the low pH springs. Our study suggests that the resident Archaea in these hot springs are acclimated if not adapted to low pH by their genetic capacity to effect the packing density of their membranes by increasing cyclopentyl rings in GDGTs at the rank of community.
[Mh] Termos MeSH primário: Archaea/metabolismo
Sedimentos Geológicos/microbiologia
Éteres de Glicerila/metabolismo
Fontes Termais/microbiologia
Lipídeos de Membrana/metabolismo
[Mh] Termos MeSH secundário: Archaea/genética
Desulfurococcales/genética
Desulfurococcales/isolamento & purificação
Meio Ambiente
Éteres de Glicerila/análise
Concentração de Íons de Hidrogênio
Lipídeos de Membrana/análise
Oxigênio/metabolismo
Filogenia
RNA Ribossômico 16S/genética
Estações do Ano
Microbiologia do Solo
Sulfolobales/genética
Sulfolobales/isolamento & purificação
Temperatura Ambiente
Thermoplasmales/genética
Thermoplasmales/isolamento & purificação
Tibet
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Glyceryl Ethers); 0 (Membrane Lipids); 0 (RNA, Ribosomal, 16S); S88TT14065 (Oxygen)
[Em] Mês de entrada:1510
[Cu] Atualização por classe:150427
[Lr] Data última revisão:
150427
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140822
[St] Status:MEDLINE
[do] DOI:10.1111/1462-2920.12595


  2 / 6 MEDLINE  
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[PMID]:23555835
[Au] Autor:Peacock JP; Cole JK; Murugapiran SK; Dodsworth JA; Fisher JC; Moser DP; Hedlund BP
[Ad] Endereço:School of Life Sciences, University of Nevada, Las Vegas, Nevada, United States of America.
[Ti] Título:Pyrosequencing reveals high-temperature cellulolytic microbial consortia in Great Boiling Spring after in situ lignocellulose enrichment.
[So] Source:PLoS One;8(3):e59927, 2013.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:To characterize high-temperature cellulolytic microbial communities, two lignocellulosic substrates, ammonia fiber-explosion-treated corn stover and aspen shavings, were incubated at average temperatures of 77 and 85°C in the sediment and water column of Great Boiling Spring, Nevada. Comparison of 109,941 quality-filtered 16S rRNA gene pyrosequences (pyrotags) from eight enrichments to 37,057 quality-filtered pyrotags from corresponding natural samples revealed distinct enriched communities dominated by phylotypes related to cellulolytic and hemicellulolytic Thermotoga and Dictyoglomus, cellulolytic and sugar-fermenting Desulfurococcales, and sugar-fermenting and hydrogenotrophic Archaeoglobales. Minor enriched populations included close relatives of hydrogenotrophic Thermodesulfobacteria, the candidate bacterial phylum OP9, and candidate archaeal groups C2 and DHVE3. Enrichment temperature was the major factor influencing community composition, with a negative correlation between temperature and richness, followed by lignocellulosic substrate composition. This study establishes the importance of these groups in the natural degradation of lignocellulose at high temperatures and suggests that a substantial portion of the diversity of thermophiles contributing to consortial cellulolysis may be contained within lineages that have representatives in pure culture.
[Mh] Termos MeSH primário: Genes Arqueais
Fontes Termais/microbiologia
Lignina/química
Consórcios Microbianos/genética
Análise de Sequência de DNA/métodos
[Mh] Termos MeSH secundário: Archaeoglobales/genética
Biodiversidade
Desulfurococcales/genética
Temperatura Alta
Nevada
Filogenia
Polissacarídeos/química
RNA Ribossômico 16S/metabolismo
Árvores/microbiologia
Água/química
Microbiologia da Água
Zea mays/microbiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Polysaccharides); 0 (RNA, Ribosomal, 16S); 059QF0KO0R (Water); 11132-73-3 (lignocellulose); 8024-50-8 (hemicellulose); 9005-53-2 (Lignin)
[Em] Mês de entrada:1401
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:130405
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0059927


  3 / 6 MEDLINE  
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[PMID]:22311159
[Au] Autor:Meyer-Dombard DR; Shock EL; Amend JP
[Ad] Endereço:Department of Earth and Environmental Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA. drmd@uic.edu
[Ti] Título:Effects of trace element concentrations on culturing thermophiles.
[So] Source:Extremophiles;16(2):317-31, 2012 Mar.
[Is] ISSN:1433-4909
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:The majority of microorganisms in natural environments resist laboratory cultivation. Sometimes referred to as 'unculturable', many phylogenetic groups are known only by fragments of recovered DNA. As a result, the ecological significance of whole branches of the 'tree of life' remains a mystery; this is particularly true when regarding genetic material retrieved from extreme environments. Geochemically relevant media have been used to improve the success of culturing Archaea and Bacteria, but these efforts have focused primarily on optimizing pH, alkalinity, major ions, carbon sources, and electron acceptor-donor pairs. Here, we cultured thermophilic microorganisms from 'Sylvan Spring' (Yellowstone National Park, USA) on media employing different trace element solutions, including one that mimicked the source fluid of the inocula. The growth medium that best simulated trace elements found in 'Sylvan Spring' produced a more diverse and faster growing mixed culture than media containing highly elevated trace element concentrations. The elevated trace element medium produced fewer phylotypes and inhibited growth. Trace element concentrations appear to influence growth conditions in extreme environments. Incorporating geochemical data into cultivation attempts may improve culturing success.
[Mh] Termos MeSH primário: Archaea/genética
Desulfurococcales/metabolismo
Oligoelementos/análise
[Mh] Termos MeSH secundário: Archaea/metabolismo
Carbono/química
Técnicas de Cultura de Células
Química/métodos
DNA/química
DNA/genética
Ecologia
Elétrons
Geologia/métodos
Concentração de Íons de Hidrogênio
Íons
Microscopia Eletrônica de Transmissão/métodos
Oxirredução
Filogenia
Sais/química
Temperatura Ambiente
Fatores de Tempo
Wyoming
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Ions); 0 (Salts); 0 (Trace Elements); 7440-44-0 (Carbon); 9007-49-2 (DNA)
[Em] Mês de entrada:1207
[Cu] Atualização por classe:171013
[Lr] Data última revisão:
171013
[Sb] Subgrupo de revista:IM; S
[Da] Data de entrada para processamento:120208
[St] Status:MEDLINE
[do] DOI:10.1007/s00792-012-0432-5


  4 / 6 MEDLINE  
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[PMID]:17720836
[Au] Autor:Boyd ES; Jackson RA; Encarnacion G; Zahn JA; Beard T; Leavitt WD; Pi Y; Zhang CL; Pearson A; Geesey GG
[Ad] Endereço:Department of Microbiology, Montana State University, 109 Lewis Hall, Bozeman, MT 59717, USA. eboyd@montana.edu
[Ti] Título:Isolation, characterization, and ecology of sulfur-respiring crenarchaea inhabiting acid-sulfate-chloride-containing geothermal springs in Yellowstone National Park.
[So] Source:Appl Environ Microbiol;73(20):6669-77, 2007 Oct.
[Is] ISSN:0099-2240
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Elemental sulfur (S(0)) is associated with many geochemically diverse hot springs, yet little is known about the phylogeny, physiology, and ecology of the organisms involved in its cycling. Here we report the isolation, characterization, and ecology of two novel, S(0)-reducing Crenarchaea from an acid geothermal spring referred to as Dragon Spring. Isolate 18U65 grows optimally at 70 to 72 degrees C and at pH 2.5 to 3.0, while isolate 18D70 grows optimally at 81 degrees C and pH 3.0. Both isolates are chemoorganotrophs, dependent on complex peptide-containing carbon sources, S(0), and anaerobic conditions for respiration-dependent growth. Glycerol dialkyl glycerol tetraethers (GDGTs) containing four to six cyclopentyl rings were present in the lipid fraction of isolates 18U65 and 18D70. Physiological characterization suggests that the isolates are adapted to the physicochemical conditions of Dragon Spring and can utilize the natural organic matter in the spring as a carbon and energy source. Quantitative PCR analysis of 16S rRNA genes associated with the S(0) flocs recovered from several acid geothermal springs using isolate-specific primers indicates that these two populations together represent 17 to 37% of the floc-associated DNA. The physiological characteristics of isolates 18U65 and 18D70 are consistent with their potential widespread distribution and putative role in the cycling of sulfur in acid geothermal springs throughout the Yellowstone National Park geothermal complex. Based on phenotypic and genetic characterization, the designations Caldisphaera draconis sp. nov. and Acidilobus sulfurireducens sp. nov. are proposed for isolates 18U65 and 18D70, respectively.
[Mh] Termos MeSH primário: Desulfurococcales
Ecossistema
Fontes Termais/química
Fontes Termais/microbiologia
Enxofre/metabolismo
[Mh] Termos MeSH secundário: Técnicas de Tipagem Bacteriana
Cloretos/análise
DNA Bacteriano/análise
Desulfurococcales/classificação
Desulfurococcales/genética
Desulfurococcales/crescimento & desenvolvimento
Desulfurococcales/isolamento & purificação
Genótipo
Concentração de Íons de Hidrogênio
Dados de Sequência Molecular
Fenótipo
Filogenia
Reação em Cadeia da Polimerase
RNA Ribossômico 16S/genética
Análise de Sequência de DNA
Sulfatos/análise
Wyoming
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Chlorides); 0 (DNA, Bacterial); 0 (RNA, Ribosomal, 16S); 0 (Sulfates); 70FD1KFU70 (Sulfur)
[Em] Mês de entrada:0712
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:070828
[St] Status:MEDLINE


  5 / 6 MEDLINE  
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[PMID]:16627639
[Au] Autor:Niederberger TD; Götz DK; McDonald IR; Ronimus RS; Morgan HW
[Ad] Endereço:Thermophile Research Unit, University of Waikato, Private Bag 3105, Hamilton, New Zealand. tdn@waikato.ac.nz
[Ti] Título:Ignisphaera aggregans gen. nov., sp. nov., a novel hyperthermophilic crenarchaeote isolated from hot springs in Rotorua and Tokaanu, New Zealand.
[So] Source:Int J Syst Evol Microbiol;56(Pt 5):965-71, 2006 May.
[Is] ISSN:1466-5026
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Consortia containing a novel coccus-shaped, anaerobic heterotroph together with Pyrobaculum rods were cultivated from geothermal environments in New Zealand. Pure cultures of the cocci were only obtained from one such consortium, despite extensive attempts. Cells of this strain (AQ1.S1T) were regular to irregular cocci in morphology and occasionally formed large aggregates, especially when utilizing polysaccharides such as konjac glucomannan as a carbon source. Strain AQ1.S1T is a hyperthermophile, with an optimal temperature for growth between 92 and 95 degrees C (range 85-98 degrees C), and a moderate acidophile, with optimal growth occurring at pH 6.4 (range 5.4-7.0). Growth was inhibited by the addition of sulphur and NaCl (optimal growth occurred without addition of NaCl) and an electron acceptor was not required. Strain AQ1.S1T utilized starch, trypticase peptone, lactose, glucose, konjac glucomannan, mannose, galactose, maltose, glycogen and beta-cyclodextrin as carbon sources. The G+C content was 52.9 mol%. Based on 16S rRNA gene sequence analysis and physiological features it is proposed that isolate AQ1.S1T (=DSM 17230T=JCM 13409T) represents the type strain of a novel species of a new genus within the Crenarchaeota, Ignisphaera aggregans gen. nov., sp. nov.
[Mh] Termos MeSH primário: Desulfurococcales/classificação
Desulfurococcales/isolamento & purificação
Fontes Termais/microbiologia
[Mh] Termos MeSH secundário: Composição de Bases
Metabolismo dos Carboidratos
Adesão Celular
DNA Bacteriano/química
DNA Bacteriano/genética
DNA Ribossômico/química
DNA Ribossômico/genética
Desulfurococcales/citologia
Desulfurococcales/fisiologia
Genes de RNAr/genética
Inibidores do Crescimento/farmacologia
Temperatura Alta
Concentração de Íons de Hidrogênio
Mananas/metabolismo
Microscopia Eletrônica de Varredura
Microscopia de Contraste de Fase
Dados de Sequência Molecular
Nova Zelândia
Peptonas/metabolismo
Filogenia
RNA Bacteriano/genética
RNA Ribossômico 16S/genética
Análise de Sequência de DNA
Cloreto de Sódio/farmacologia
Enxofre/farmacologia
Microbiologia da Água
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Bacterial); 0 (DNA, Ribosomal); 0 (Growth Inhibitors); 0 (Mannans); 0 (Peptones); 0 (RNA, Bacterial); 0 (RNA, Ribosomal, 16S); 36W3E5TAMG ((1-6)-alpha-glucomannan); 451W47IQ8X (Sodium Chloride); 70FD1KFU70 (Sulfur)
[Em] Mês de entrada:0609
[Cu] Atualização por classe:161128
[Lr] Data última revisão:
161128
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:060422
[St] Status:MEDLINE


  6 / 6 MEDLINE  
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[PMID]:15686840
[Au] Autor:Iwabata H; Watanabe K; Ohkuri T; Yokobori S; Yamagishi A
[Ad] Endereço:Department of Molecular Biology, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
[Ti] Título:Thermostability of ancestral mutants of Caldococcus noboribetus isocitrate dehydrogenase.
[So] Source:FEMS Microbiol Lett;243(2):393-8, 2005 Feb 15.
[Is] ISSN:0378-1097
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:We constructed mutant genes of Caldococcus noboribetus isocitrate dehydrogenase containing ancestral amino acid residues that were inferred using the maximal likelihood method and a composite phylogenetic tree of isocitrate dehydrogenase and 3-isopropylmalate dehydrogenase. The mutant genes were expressed in Escherichia coli and the protein products purified. Thermostabilities, reported as the half-inactivation temperatures, for the purified enzymes were determined and compared with that of the wild-type enzyme. Four of the five mutant enzymes have greater thermal stabilities than wild-type isocitrate dehydrogenase. The results are compatible with the hyperthermophilic universal ancestor (commonote) hypothesis. Incorporation of ancestral residues into a modern-day protein sequence can be used to improve protein thermostability.
[Mh] Termos MeSH primário: Desulfurococcales/enzimologia
Temperatura Alta
Isocitrato Desidrogenase/química
Isocitrato Desidrogenase/genética
Mutação
Filogenia
[Mh] Termos MeSH secundário: 3-Isopropilmalato Desidrogenase
Oxirredutases do Álcool/genética
Sequência de Aminoácidos
Desulfurococcales/classificação
Desulfurococcales/genética
Estabilidade Enzimática
Evolução Molecular
Isocitrato Desidrogenase/metabolismo
Modelos Moleculares
Dados de Sequência Molecular
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
EC 1.1.- (Alcohol Oxidoreductases); EC 1.1.1.41 (Isocitrate Dehydrogenase); EC 1.1.1.85 (3-Isopropylmalate Dehydrogenase)
[Em] Mês de entrada:0506
[Cu] Atualização por classe:081121
[Lr] Data última revisão:
081121
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:050203
[St] Status:MEDLINE



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