321 research outputs found

    High temperature microbial activity in upper soil layers

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    Biomineralization at high temperatures in upper soil layers has been largely ignored, although desertification and global warming have led to increasing areas of soils exposed to high temperatures. Recent publications evidenced thermophilic bacteria ubiquity in soils as viable cells, and their role in nutrient cycling and seedling development. High temperature events, frequently observed at medium and low latitudes, locate temporal niches for thermophiles to grow in soils. There, at temperatures inhibitory for common mesophiles, thermophilic bacteria could perform biogeochemical reactions important to the soil food web. Nutrient cycling analyses in soils at medium and low latitudes would benefit from considering the potential role of thermophiles. © FEMS 2015.This work was funded by FEDER Funds through the Operational Programme for Competitiveness Factors – COMPETE, and National Funds through the Foundation for Science and Technology (FCT) under the Strategic Project PEst-C/AGR/UI0115/2011 to MMS, and by the Regional Government of Andalusia, projects BIO288 and RNM2529, and the Spanish Ministry of Economy and Productiveness, projects CGL2009-12328/BOS, CGL2014-58762-P and CONSOLIDER CSD2009-00006 to JMG, also cofunded by FEDER funds.Peer reviewe

    Hydrolytic enzyme activity enhanced by Barium supplementation

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    10 páginas.-- 2 figuras.-- 1 tabla.-- 26 referenciasHydrolysis of polymers is a first and often limiting step during the degradation of plant residues. Plant biomass is generally a major component of waste residues and a major renewable resource to obtain a variety of secondary products including biofuels. Improving the performance of enzymatic hydrolysis of plant material with minimum costs and limiting the use of additional microbial biomass or hydrolytic enzymes directly influences competitiveness of these green biotechnological processes. In this study, we cloned and expressed a cellulase and two esterases recovered from environmental thermophilic soil bacterial communities and characterize their optimum activity conditions including the effect of several metal ions. Results showed that supplementing these hydrolytic reactions with Barium increases the activity of these extracellular hydrolytic enzymes. This observation represents a simple but major improvement to enhance the efficiency and competitiveness of this process within an increasingly important biotechnological sector.Support from the Spanish Ministry of Economy and Competitiveness (CONSOLIDER CSD2009-00006, CGL2014-58762-P, CTM2014-55095), the Andalusian Government (BIO288 and RNM2529), both cofinanced by FEDER funds, intramural project OEP2011 (201570I020), the mobility programme 003-ABEL-CM-2013 (NILS Science and Sustainability programme, EEA grants), the mobility and coordination European project ALGAENET (Marie Curie Actions IRSES- 295165, FP7-PEOPLE-2011) and COST Action ES1302.Peer reviewe

    Bacterial diversity in the cave of Altamira.

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    5 pages, 1 figure, 2 tables, 14 references. Electronic Newsletter. CSIC Thematic Network on Cultural Heritage and Network on Science and Technology for the Conservation of Cultural Heritage Instituto de Recursos Naturales y AgrobiologĂ­a de Sevilla, CSIC, Apartado de Correos 1052, 41080 Sevilla (Spain).The study of microorganisms involved in deterioration of prehistoric paintings is of great importance to preserve these singular samples of cultural heritage. This study presents, as an example, results from a research carried out in Altamira Cave (Cantabria, Spain). Altamira Cave contains numerous and well known paintings from the Upper Palaeolithic, dated back around 15,000 years. This work focused in understanding the microorganisms inhabiting this singular system and the potential consequences of its microbial diversity for conservation of these valuable paintings.The authors acknowledge financial support from the Spanish Ministry of Education and Science (project CGL2006-07424/BOS) and the Spanish Ministry of Culture.Peer reviewe

    Cellular Viscosity in Prokaryotes and Thermal Stability of Low Molecular Weight Biomolecules

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    8 páginas.-- 6 figuras.-- 32 referenciasSome low molecular weight biomolecules, i.e., NAD(P)H, are unstable at high temperatures. The use of these biomolecules by thermophilic microorganisms has been scarcely analyzed. Herein, NADH stability has been studied at different temperatures and viscosities. NADH decay increased at increasing temperatures. At increasing viscosities, NADH decay rates decreased. Thus, maintaining relatively high cellular viscosity in cells could result in increased stability of low molecular weight biomolecules (i.e., NADH) at high temperatures, unlike what was previously deduced from studies in diluted water solutions. Cellular viscosity was determined using a fluorescent molecular rotor in various prokaryotes covering the range from 10 to 100°C. Some mesophiles showed the capability of changing cellular viscosity depending on growth temperature. Thermophiles and extreme thermophiles presented a relatively high cellular viscosity, suggesting this strategy as a reasonable mechanism to thrive under these high temperatures. Results substantiate the capability of thermophiles and extreme thermophiles (growth range 50–80°C) to stabilize and use generally considered unstable, universal low molecular weight biomolecules. In addition, this study represents a first report, to our knowledge, on cellular viscosity measurements in prokaryotes and it shows the dependency of prokaryotic cellular viscosity on species and growth temperature.The authors acknowledge funding from projects No. CSD2009-0006 and No. CGL2014-58762-P from the Spanish Ministry of Economy and Competitiveness and grants No. BIO-288 and No. RNM2529 from the Andalusian Government. Federal funds cofinanced these projects. Funding from the mobility program No. 003-ABEL-CM-2013 (NILS Science and Sustainability program, EEA grants) is also acknowledged.Peer Reviewe

    Influence of Temperature and Copper on Oxalobacteraceae in Soil Enrichments

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    7 páginas.-- 3 figuras.-- 3 tablas.-- 30 referenciasβ-Proteobacteria is one of the most abundant phylum in soils, including autotrophic and heterotrophic ammonium-consumers with relevance in N circulation in soils. The effects of high-temperature events and phytosanitary treatments, such as copper amendments, on soil bacterial communities relevant to N-cycling remain to be studied. As an example, South Portugal soils are seasonally exposed to high-temperature periods, the temperature at the upper soil layers can reach over 40 °C. Here, we evaluated the dynamics of mesophilic and thermophilic bacteria from a temperate soil, in particular of heterotrophic β-Proteobacteria, regarding the ammonium equilibrium, as a function of temperature and copper treatment. Soil samples were collected from an olive orchard in southern Portugal. Selective enrichments were performed from samples under different conditions of temperature (30 and 50 °C) and copper supplementation (100 and 500 µM) in order to mime seasonal variations and phytosanitary treatments. Changes in the microbial communities under these conditions were examined by denaturing gradient gel electrophoresis, a molecular fingerprint technique. At moderate temperature—30 °C—either without or with copper addition, dominant members were identified as different strains belonging to genus Massilia, a genus of the Oxalobacteraceae (β-Proteobacteria), while at 50 °C, members of the Brevibacillus genus, phylum Firmicutes were also represented. Ammonium production during bacterial growth at moderate and high temperatures was not affected by copper addition. Results indicate that both copper and temperature selected specific tolerant bacterial strains with consequences for N-cycling in copper-treated orchards.This work was funded by FEDER Funds through the Operational Programme for Competitiveness Factors COMPETE and National Funds through FCT Foundation for Science and Technology under the Strategic Project PEst-C/AGR/UI0115/2011. We thank Eng. G. Pinheiro, from Eugénio Almeida Foundation (FEA) for providing access to the FEA olive orchard.Peer reviewe

    Kinetics of Indigenous Nitrate Reducing Sulfide Oxidizing Activity in Microaerophilic Wastewater Biofilms

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    23 páginas.-- 10 figuras.-- 2 tablas.-- 74 referencias.-- Supporting Information: Dataset. in http://dx.doi.org/10.1371/journal.pone.0149096Nitrate decreases sulfide release in wastewater treatment plants (WWTP), but little is known on how it affects the microzonation and kinetics of related microbial processes within the biofilm. The effect of nitrate addition on these properties for sulfate reduction, sulfide oxidation, and oxygen respiration were studied with the use of microelectrodes in microaerophilic wastewater biofilms. Mass balance calaculations and community composition analysis were also performed. At basal WWTP conditions, the biofilm presented a double-layer system. The upper microaerophilic layer (~300 μm) showed low sulfide production (0.31 μmol cm-3 h-1) and oxygen consumption rates (0.01 μmol cm-3 h-1). The anoxic lower layer showed high sulfide production (2.7 μmol cm-3 h-1). Nitrate addition decreased net sulfide production rates, caused by an increase in sulfide oxidation rates (SOR) in the upper layer, rather than an inhibition of sulfate reducing bacteria (SRB). This suggests that the indigenous nitrate reducing-sulfide oxidizing bacteria (NR-SOB) were immediately activated by nitrate. The functional vertical structure of the biofilm changed to a triple-layer system, where the previously upper sulfide-producing layer in the absence of nitrate split into two new layers: 1) an upper sulfide-consuming layer, whose thickness is probably determined by the nitrate penetration depth within the biofilm, and 2) a middle layer producing sulfide at an even higher rate than in the absence of nitrate in some cases. Below these layers, the lower net sulfide-producing layer remained unaffected. Net SOR varied from 0.05 to 0.72 μmol cm-3 h-1 depending on nitrate and sulfate availability. Addition of low nitrate concentrations likely increased sulfate availability within the biofilm and resulted in an increase of both net sulfate reduction and net sulfide oxidation by overcoming sulfate diffusional limitation from the water phase and the strong coupling between SRB and NR-SOB syntrophic relationshipAC was funded by projects P06-RNM-01787, P11-RNM-7199, the PAI group RNM-214 from Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía and CTM2013-43857-R from the Spanish Ministry of Economy and Competitiveness. JMG was funded by the PAI group BIO-288 from Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

    Procedimiento de estabilización de biomoléculas

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    La presente invención se refiere a un procedimiento para la estabilización de biomoléculas caracterizado porque dicha estabilización se consigue manteniendo la viscosidad del medio en el cual se encuentran dichas biomoléculas. Es de aplicación a un amplio número de biomoléculas tales como ATP o NADH y permite la utilización de las mismas en procedimientos analíticos, clínicos o médicos que se vayan a llevar a cabo en condiciones no adecuadas para el mantenimiento de su estabilidad.Peer reviewedConsejo Superior de Investigaciones CientíficasB1 Patente sin examen previ

    Differentiation of a hyperthermophilic archaeon Pyrococcus sp. Strain Pikanate 5017, by arbitrarily primed PCR

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    Pyrococcus and Thermococcus are hyperthermophilic archaea in the order Thermococcales. Both genera are strictly anaerobes, gaining energy by fermentation of peptide and several carbohydrates at optimal temperature above 70 ° C. A Pyrococcus sp. strain Pikanate 5017 (PK 5017) was recently isolated from a hot spring in Northern Thailand. The strain PK 5017 is a valuable source of numerous genes encoding thermostable enzymes. Growth kinetics determined at various temperatures (75-105 ° C) indicates that strain PK5017 is a fast growing archaeon. An arbitrarily primed PCR (AP-PCR) technique was successfully applied to differentiate the genome sequences of six members of Thermococcales. Two single primers, ARB-1f (5’ ATGAG GACT GAAA CCATT 3’) and ARB-2f (5’ GTAAA ACGA CGGC CAGT 3’), are effective in producing polymorphisms of the PCR products at 3-10 ng of DNAs. The unique AP-PCR fingerprints distinguish the strain PK5017 from P. furiosus, P. horikoshii, P. abyssi, T. litoralis, and T. celer. The results indicate a clear distinction of genome sequences among Pyrococcus and Thermococcus genera.This work was supported by a grant from the Scientific Promotion and Development Fund, Faculty of Science, Silpakorn University (Grant number RGI 2553-06). JMG and MCP acknowledge the support from a CSIC movility program, PA1001993 and PA1002058, and the Andalusian Government Bio288Peer Reviewe

    Identification and characterization of a freshwater Pyrococcus sp. strain PK 5017 and identification of pfu-like IS elements in Thermococcus sibiricus MM 739

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    12 pages, 7 figures, 1 table, 32 references.A strictly anaerobic, hyperthermophilic Pyrococcus sp. strain PK 5017 (PK 5017) was isolated from a freshwater hot spring in Thailand. Cells of strain PK 5017 are irregular cocci occurring singly and in pairs with a diameter range of 0.7-1.2 µm. Temperature, pH and NaCl concentration ranges for growth are 75-105 oC (opt. temp. = 95-100 oC), pH 5-7.8 (opt. pH = 7.2) and 2.5-IS-pfu-Ts1> and >IS-pfu-Ts2> are identified in the complete genome sequence of Thermococcus sibiricus MM 739. Pyrococcus sp. strain PK 5017 = Pyrococcus sp. strain Pikanate 5017 = JCM17043 = ATCC BAA-2246.This work was supported by the Scientific Promotion and Development Fund, Faculty of Science, Silpakorn University (RGI 2553-06) and Silpakorn University Research and Development Institute (SURDI 54/01/18 and SURDI 55/01/05). JMG and MCP acknowledge support from a CSIC movility program, PA1001993 and PA1002058, and the Andalusian Government Bio288 which included FEDER funds.Peer Reviewe

    A procedure to evaluate the resistance to biological colonization as a characteristic for product quality of ceramic roofing tiles

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    9 pages, 5 figures, 4 tables, 22 references. The authors acknowledge the collaboration of the company Cerámica La Escandella (Spain) in supplying the samples of ceramic roofing tiles, and the advice and support by Dr. José Enrique Frias (Servicio de Cultivos Biológicos, Instituto de Biologia Vegetal y Fotosíntesis, CSIC, Seville, Spain) who provided us with the cyanobacterial strains used in this work.Ceramic roofing tiles suffer deterioration through time due to environmental exposure. Biological colonization affects the appearance and integrity of building materials, such as roofing tiles. The resistance to biocolonization represents an important property affecting the product quality of ceramic roofing tiles. While natural colonization of roofing tiles by organisms is a progressive, heterogeneous, and slow process, laboratory assessment of this phenomenon requires a sensitive procedure that can be carried out within a reasonable period of time. Different microorganisms have been evaluated and the use of phototrophs, specifically the cyanobacterium Oscillatoria, presented several advantages such as good adherence, homogeneous growth on surfaces, and the chlorophyll-autofluorescence which can be used for a sensitive detection. Colonization by Oscillatoria on roofing tiles was assessed by measuring the autofluorescence of cells. This study proposes the use of specific cyanobacterial cells and a simple method for monitoring biofilm formation and biological colonization of roofing tiles.. This study was funded by project PET2007-0080 from the Spanish Ministry of Science and Innovation.Peer reviewe
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