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Pierre Regnier - One of the best experts on this subject based on the ideXlab platform.
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modeling microbial reaction rates in a Submarine Hydrothermal Vent chimney wall
Geochimica et Cosmochimica Acta, 2014Co-Authors: Douglas E Larowe, Andrew W Dale, D R Aguilera, Ivan Lheureux, Jan P Amend, Pierre RegnierAbstract:The fluids emanating from active Submarine Hydrothermal Vent chimneys provide a window into subseafloor processes and, through mixing with seawater, are responsible for steep thermal and compositional gradients that provide the energetic basis for diverse biological communities. Although several models have been developed to better understand the dynamic interplay of seawater, Hydrothermal fluid, minerals and microorganisms inside chimney walls, none provide a fully integrated approach to quantifying the biogeochemistry of these Hydrothermal systems. In an effort to remedy this, a fully coupled biogeochemical reaction-transport model of a Hydrothermal Vent chimney has been developed that explicitly quantifies the rates of microbial catalysis while taking into account geochemical processes such as fluid flow, solute transport and oxidation–reduction reactions associated with fluid mixing as a function of temperature. The metabolisms included in the reaction network are methanogenesis, aerobic oxidation of hydrogen, sulfide and methane and sulfate reduction by hydrogen and methane. Model results indicate that microbial catalysis is generally fastest in the hottest habitable portion of the Vent chimney (77–102 °C), and methane and sulfide oxidation peak near the seawater-side of the chimney. The fastest metabolisms are aerobic oxidation of H2 and sulfide and reduction of sulfate by H2 with maximum rates of 140, 900 and 800 pmol cm−3 d−1, respectively. The maximum rate of hydrogenotrophic methanogenesis is just under 0.03 pmol cm−3 d−1, the slowest of the metabolisms considered. Due to thermodynamic inhibition, there is no anaerobic oxidation of methane by sulfate (AOM). These simulations are consistent with Vent chimney metabolic activity inferred from phylogenetic data reported in the literature. The model developed here provides a quantitative approach to describing the rates of biogeochemical transformations in Hydrothermal systems and can be used to constrain the role of microbial activity in the deep subsurface.
Mottl Michael - One of the best experts on this subject based on the ideXlab platform.
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VentDB: EPR13N, Mid-Ocean Ridge Hydrothermal Vent Chemistry Data Collection. Michard (1984), Grimaud (1984), Michard (1983), Merlivat (1987), Michard (1986), Palmer (1992), Douville (1999)
Interdisciplinary Earth Data Alliance (IEDA), 2012Co-Authors: Mottl MichaelAbstract:Collection of Hydrothermal Vent fluid chemistry data from EPR13N – Major Elements, REE, Stable Isotopes. This collection contains both the raw chemical data where possible, as well calculated chemical end-member compositions (see readme file included for details). This file is just one part of a much larger effort (VentDB) to make available to the scientific community as much Hydrothermal ridge Vent chemistry data as possible (for a list of all the VentDB related data collections available, search the EarthChem Library for the term “VentDB”). For more information about this compilation, please see "Explanatory Notes and Master Chemical Item Spreadsheet for the VentDB Data Collections housed in the EarthChem Library" (M. Mottl), available at www.earthchem.org/library.Michard, G., F. Albarede, A. Michard, J.-F. Minster, J.-L. Charlou, and N.Tan (1984), “Chemistry of solutions from the 13°N East Pacific Rise Hydrothermal site”, Earth and Planetary Science Letters, 67, 297-307 Grimaud, D., A. Michard, and G. Michard (1984), “Composition chimique et composition isotopique du strontium dans les eaux Hydrothermales sous-marines de la dorsale Est Pacifique a 13° Nord, Comptes R. Acad. Sci. Paris”, 299, Series II, no. 13, 865-870 Michard, A., F. Albarede, G. Michard, J.-F. Minster, and J.-L. Charlou (1983), “Rare-earth elements and uranium in high-temperature solutions from East Pacific Rise Hydrothermal field (13°N)”, Nature, 303, 795-797 Merlivat, L., F. Pineau, and M. Javoy (1987), “Hydrothermal Vent waters at 13°N on the East Pacific Rise: isotopic composition and gas concentration”, Earth and Planetary Science Letters, 84, 100-108 Michard, A., and F. Albarede (1986), “The REE content of some Hydrothermal fluids”, Chemical Geology, 55, 51-60 Palmer, M.R. (1992), “Controls over the chloride concentration of Submarine Hydrothermal Vent fluids: evidence from Sr/Ca and 87Sr/86Sr ratios”, Earth and Planetary Science Letters, 109, 37-46 Douville, E., P. Bienvenue, J.L. Charlou, J.P.Donval, Y. Fouquet, P. Appriou, and T. Gamo (1999), “Yttrium and rare earth elements in fluids fom various deep-sea Hydrothermal systems”, Geochimica et Cosmochimica Acta, 63, 627-64
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VentDB: EPR11-13N, Mid-Ocean Ridge Hydrothermal Vent Chemistry Data Collection. Bowers (1988), Campbell (1989), Campbell (1994), Chan (1993), Klinkhammer (1994), Palmer (1989 a,b), Palmer (1992), Spivack (1987)
Interdisciplinary Earth Data Alliance (IEDA), 2012Co-Authors: Mottl MichaelAbstract:Collection of Hydrothermal Vent fluid chemistry data from EPR11-13N - End-member data for major, minor, and trace species, transition metals, rare earth elements, and isotopes of Li, B, and Sr. This file is just one part of a much larger effort (VentDB) to make available to the scientific community as much Hydrothermal ridge Vent chemistry data as possible (for a list of all the VentDB related data collections available, search the EarthChem Library for the term “VentDB”). For more information about this compilation, please see “Explanatory Notes and Master Chemical Item Spreadsheet for the VentDB Data Collections housed in the EarthChem Library” (M. Mottl), available at www.earthchem.org/library.Bowers, T.S., A.C. Campbell, C.I. Measures, A.J. Spivack, M. Khadem, and J.M. Edmond (1988), Chemical controls on the composition of Vent fluids at 13o-11oN and 21oN, East Pacific Rise, Journal of Geophysical Research, 93, 4522-4536 Campbell, A.C., and J.M. Edmond (1989), Halide systematics of Submarine Hydrothermal Vents, Nature, 342, 168-170 Campbell, A.C., C.R. German, M.R. Palmer, T. Gamo, and J.M. Edmond (1994), Chemistry of Hydrothermal fluids from Escanaba Trough, Gorda Ridge, U.S. Geological Survey Bulletin, 2022, 201-221 Chan, L.-H., J.M. Edmond, and G. Thompson (1993), A lithium isotope study of hot springs and metabasalts from mid-ocean ridge Hydrothermal systems, Journal of Geophysical Research, 98, 9653-9659 Klinkhammer, G.P., H. Elderfield, J.M. Edmond, and A. Mitra (1994), Geochemical implications of rare earth element patterns in Hydrothermal fluids from mid-ocean ridges, Geochimica et Cosmochimica Acta, 58, 5105-5113 Palmer, M.R. (1992), Controls over the chloride concentration of Submarine Hydrothermal Vent fluids: evidence from Sr/Ca and 87Sr/86Sr ratios, Earth and Planetary Science Letters, 109, 37-46 Palmer, M.R., and J.M. Edmond (1989a), The strontium isotope budget of the modern ocean, Earth and Planetary Science Letters, 92, 11-26 Palmer, M.R., and J.M. Edmond (1989b), Cesium and rubidium in Submarine Hydrothermal fluids: evidence for recycling of alkali elements, Earth and Planetary Science Letters, 95, 8-14 Spivack, A.J., and J.M. Edmond (1987), Boron isotope exchange between seawater and the oceanic crust, Geochimica et Cosmochimica Acta, 51, 1033-104
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VentDB: EPR21N, Mid-Ocean Ridge Hydrothermal Vent Chemistry Data Collection. Von Damm (1983), Albarede (1981), Bourles (1991), Campbell (1988), Campbell (1989), Chan (1993), Chen (1986), Klinkhammer (1994), Michard (1986), Mortlock (1993), Palmer (1989 a,b), Palmer (1991), Palmer (1992), Spivack (1987), Von Damm (1985), Von Damm (1990), Woodruff (1988)
Interdisciplinary Earth Data Alliance (IEDA), 2012Co-Authors: Mottl MichaelAbstract:Collection of Hydrothermal Vent fluid chemistry data from EPR21N - Raw and end-member data for major, minor, and trace species, transition metals, U, rare earth elements, nutrients, and isotopes of Li, Be, B, S, Sr, U, and Pb. This file is just one part of a much larger effort (VentDB) to make available to the scientific community as much Hydrothermal ridge Vent chemistry data as possible (for a list of all the VentDB related data collections available, search the EarthChem Library for the term “VentDB”). For more information about this compilation, please see “Explanatory Notes and Master Chemical Item Spreadsheet for the VentDB Data Collections housed in the EarthChem Library” (M. Mottl), available at www.earthchem.org/library.Von Damm, K.L. (1983), Chemistry of Submarine Hydrothermal solutions at 21°N, East Pacific Rise and Guaymas Basin,Gulf of California, Ph.D. thesis, WHOI-MIT Joint Program in Oceanography, 240 pp. Albarede, F., A. Michard, J.F. Minster, and G. Michard (1981), 87Sr/86Sr ratios in Hydrothermal waters and deposits from the East Pacific Rise at 21oN, Earth and Planetary Science Letters, 55, 229-236 Bourles, D.L., G.M. Taisbeck, E.T. Brown, F. Yiou, and J.M. Edmond (1991), Beryllium isotope systematics of Submarine Hydrothermal systems, Earth and Planetary Science Letters, 105, 534-542 Campbell, A.C., and J.M. Edmond (1989), Halide systematics of Submarine Hydrothermal Vents, Nature, 342, 168-170 Campbell, A.C., T.S. Bowers, C.I. Measures, K.Kl. Falkner, M. Khadem, and J.M. Edmond (1988), A time series of Vent fluid compositions from 21oN, East Pacific Rise (1979, 1981, 1985), and the Guaymas Basin, Gulf of California (1982, 1985), Journal of Geophysical Research, 93, 4537-4549 Chan, L.-H., J.M. Edmond, and G. Thompson (1993), A lithium isotope study of hot springs and metabasalts from mid-ocean ridge Hydrothermal systems, Journal of Geophysical Research, 98, 9653-9659 Chen, J.H., G.J. Wasserburg, K.L. Von Damm, and J.M. Edmond (1986), The U-Th-Pb systematics in hot springs on the East Pacific Rise at 21°N and Guaymas Basin, Geochimica et Cosmochimica Acta, 50, 2467-2479 Klinkhammer, G.P., H. Elderfield, J.M. Edmond, and A. Mitra (1994), Geochemical implications of rare earth element patterns in Hydrothermal fluids from mid-ocean ridges, Geochimica et Cosmochimica Acta, 58, 5105-5113 Michard, A., and F. Albarede (1986), The REE content of some Hydrothermal fluids, Chemical Geology, 55, 51-60 Mortlock, R.A., P.N. Froelich, R.A. Feely, G.J. Massoth, D.A. Butterfield, and J.E. Lupton (1993), Silica and germanium in Pacific Ocean Hydrothermal Vents and plumes, Earth and Planetary Science Letters, 119, 365-378 Palmer, M.R. (1991), Boron isotope systematics of Hydrothermal fluids and tourmalines: a synthesis, Chemical Geology (Isotope Geoscience Section), 94, 111-121 Palmer, M.R. (1992), Controls over the chloride concentration of Submarine Hydrothermal Vent fluids: evidence from Sr/Ca and 87Sr/86Sr ratios, Earth and Planetary Science Letters, 109, 37-46 Palmer, M.R., and J.M. Edmond (1989a), The strontium isotope budget of the modern ocean, Earth and Planetary Science Letters, 92, 11-26 Palmer, M.R., and J.M. Edmond (1989b), Cesium and rubidium in Submarine Hydrothermal fluids: evidence for recycling of alkali elements, Earth and Planetary Science Letters, 95, 8-14 Spivack, A.J., and J.M. Edmond (1987), Boron isotope exchange between seawater and the oceanic crust, Geochimica et Cosmochimica Acta, 51, 1033-1043 Von Damm, K.L. (1990), Seafloor Hydrothermal activity: black smoker chemistry and chimneys, Annual Reviews of Earth and Planetary Science, 18, 173-204 Von Damm, K.L., J.M. Edmond, B. Grant, C.I. Measures, B. Walden, and R.F. Weiss (1985), Chemistry of Submarine Hydrothermal solutions at 21°N, East Pacific Rise, Geochimica et Cosmochimica Acta, 49, 2197-2230 Woodruff, L.G., and W.C. Shanks III (1988), Sulfur isotope study of chimney minerals and Vent fluids from 21°N, East Pacific Rise: Hydrothermal sulfur sources and disequilibrium sulfate reduction, Journal of Geophysical Research, 93, 4562-457
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VentDB: Mid-Atlantic Ridge, TAG MARK, Mid-Ocean Ridge Hydrothermal Vent Chemistry Data Collection. Campbell (1988), Bau (1999) Bourles (1994), Campbell (1989), Campbell (1994), Chan (1993), Charlou (1996), Douville (1999), Edmond (1995), Edmonds (1996), Gamo (1996), James (1996), Jean-Baptiste (1991), Klinkhammer, Metz and Trefry (2000), Michard (1989), Mitra (1994), Palmer (1991), Palmer (1992), Palmer (1989a,b), Rudnicki and Elderfield (1992)
Interdisciplinary Earth Data Alliance (IEDA), 2012Co-Authors: Mottl MichaelAbstract:Collection of Hydrothermal Vent fluid chemistry data from Mid-Atlantic Ridge, TAG MARK - Raw and end-member data for major, minor, and trace species, transition metals, U, rare earth elements, dissolved gases, nutrients, and isotopes of O, He, Li, Be, B, C,S, Rn, and Ra. This file is just one part of a much larger effort (VentDB) to make available to the scientific community as much Hydrothermal ridge Vent chemistry data as possible (for a list of all the VentDB related data collections available, search the EarthChem Library for the term “VentDB”). For more information about this compilation, please see “Explanatory Notes and Master Chemical Item Spreadsheet for the VentDB Data Collections housed in the EarthChem Library” (M. Mottl), available at www.earthchem.org/library.Campbell, A.C., M.R. Palmer, G.P. Klinkhammer, T.S. Bowers, J.M. Edmond, J.R. Lawrence, J.F. Casey, G. Thompson, S. Humphris, P. Rona, and J.A. Karson (1988), Chemistry of hot springs on the Mid-Atlantic Ridge, Nature, 335, 514 Bau, M., and P. Dulski (1999), Comparing yttrium and rare earths in Hydrothermal fluids from the Mid-Atlantic Ridge: implications for Y and REE behaviour during near-Vent mixing and for the Y/Ho ratio of Proterozoic seawater, Chemical Geology, 155, 77-90 Bourles, D.L., E.T. Brown, C.R.German, C.I. Measures, J.M. Edmond, G.M. Raisbeck, and F. Yiou (1994), Examination of Hydrothermal influences on oceanic beryllium using fluids, plume particles and sediments from the TAG Hydrothermal field, Earth and Planetary Science Letters, 122, 143-157 Campbell, A.C., and J.M. Edmond (1989), Halide systematics of Submarine Hydrothermal Vents, Nature, 342, 168-170 Campbell, A.C., C.R. German, M.R. Palmer, T. Gamo, and J.M. Edmond (1994), Chemistry of Hydrothermal fluids from Escanaba Trough, Gorda Ridge, U.S. Geological Survey Bulletin, 2022, 201-221 Chan, L.-H., J.M. Edmond, and G. Thompson (1993), A lithium isotope study of hot springs and metabasalts from mid-ocean ridge Hydrothermal systems, Journal of Geophysical Research, 98, 9653-9659 Charlou, J.L., J.P. Donval, P. Jean-Baptiste, and A. Dapoigny (1996), Gases and helium isotopes in high temperature solutions sampled before and after ODP Leg 158 drilling at TAG Hydrothermal field (26°N, MAR), Geophysical Research Letters, 23, 3491-3494 Douville, E., P. Bienvenue, J.L. Charlou, J.P.Donval, Y. Fouquet, P. Appriou, and T. Gamo (1999), Yttrium and rare earth elements in fluids fom various deep-sea Hydrothermal systems, Geochimica et Cosmochimica Acta, 63, 627-643 Edmond, J.M., A.C. Campbell, M.R. Palmer, G.P Klinkhammer, C.R. German, H.N. Edmonds, H. Elderfield, G. Thompson, and P. Rona (1995), Time series studies of Vent fluids from the TAG and MARK sites (1986, 1990) Mid-Atlantic Ridge: a new solution chemistry model and a mechanism for Cu/Zn zonation in massive sulphide orebodies, Hydrothermal Vents and Processes (L.M. Parson, C.L. Walker, and D.R. Dixon, eds.), Geological Society Special Publication No. 87, 77-86 Edmonds, H.N., C.R. German, D.R.H. Green, Y. Huh, T. Gamo, and J.M. Edmond (1996), Continuation of the Hydrothermal fluid chemistry time series at TAG, and the effects of ODP drilling, Geophysical Research Letters, 23, 3487-3489 Gamo, T., H. Chiba, H. Masuda, H.N. Edmonds, K. Fujioka, Y. Kodama, H. Nanba, and Y. Sano (1996), Chemical characteristics of Hydrothermal fluids form the TAG mound of the Mid-Atlantic Ridge in August 1994: implications for spatial and temporal variability of Hydrothermal activity, Geophysical Research Letters, 23, 3483-3486 James, R.H., and H. Elderfield (1996), Chemistry of ore-forming fluids and mineral formation rates in an active Hydrothermal sulfide deposit on the Mid-Atlantic Ridge, Geology, 24, 1147-1150 Jean-Baptiste, P., J.L. Charlou, M. Stievenard, J.P. Donval, H. Bougault, and C. Mevel (1991), Helium and methane measurements in Hydrothermal fluids from the Mid-Atlantic Ridge: the Snake Pit site at 23°N, Earth and Planetary Science Letters, 106, 17-28 Klinkhammer, G.P., H. Elderfield, J.M. Edmond, and A. Mitra (1994), Geochemical implications of rare earth element patterns in Hydrothermal fluids from mid-ocean ridges, Geochimica et Cosmochimica Acta, 58, 5105-5113 Metz, S., and J.H. Trefry (2000), Chemical and mineralogical influences on concentrations of trace metals in Hydrothermal fluids, Geochimica et Cosmochimica Acta, 64, 2267-2279 Michard, A. (1989), Rare earth element systematics in Hydrothermal fluids, Geochimica et Cosmochimica Acta, 53, 745-750 Mitra, A., H. Elderfield, and M.J. Greaves (1994), Rare earth elements in Submarine Hydrothermal fluids and plumes from the Mid-atlantic Ridge, Marine Chemistry, 46, 217-235 Palmer, M.R. (1991), Boron isotope systematics of Hydrothermal fluids and tourmalines: a synthesis, Chemical Geology (Isotope Geoscience Section), 94, 111-121 Palmer, M.R. (1992), Controls over the chloride concentration of Submarine Hydrothermal Vent fluids: evidence from Sr/Ca and 87Sr/86Sr ratios, Earth and Planetary Science Letters, 109, 37-46 Palmer, M.R., and J.M. Edmond (1989a), The strontium isotope budget of the modern ocean, Earth and Planetary Science Letters, 92, 11-26 Palmer, M.R., and J.M. Edmond (1989b), Cesium and rubidium in Submarine Hydrothermal fluids: evidence for recycling of alkali elements, Earth and Planetary Science Letters, 95, 8-14 Rudnicki, M.D., and H. Elderfield (1992), Helium, radon, and manganese at the TAG and Snakepit Hydrothermal Vent fields, 26° and 23°N, Mid-Atlantic Ridge, Earth and Planetary Science Letters, 113, 307-32
Andrew Maffei - One of the best experts on this subject based on the ideXlab platform.
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An authoritative global database for active Submarine Hydrothermal Vent fields
Geochemistry Geophysics Geosystems, 2013Co-Authors: Stace E. Beaulieu, Castro RodrÍguez Anibal German, Edward T. Baker, Andrew MaffeiAbstract:The InterRidge Vents Database is available online as the authoritative reference for locations of active Submarine Hydrothermal Vent fields. Here we describe the revision of the database to an open source content management system and conduct a meta-analysis of the global distribution of known active Vent fields. The number of known active Vent fields has almost doubled in the past decade (521 as of year 2009), with about half visually confirmed and others inferred active from physical and chemical clues. Although previously known mainly from mid-ocean ridges (MORs), active Vent fields at MORs now comprise only half of the total known, with about a quarter each now known at volcanic arcs and back-arc spreading centers. Discoveries in arc and back-arc settings resulted in an increase in known Vent fields within exclusive economic zones, consequently reducing the proportion known in high seas to one third. The increase in known Vent fields reflects a number of factors, including increased national and commercial interests in seafloor Hydrothermal deposits as mineral resources. The purpose of the database now extends beyond academic research and education and into marine policy and management, with at least 18% of known Vent fields in areas granted or pending applications for mineral prospecting and 8% in marine protected areas.
Gerard Muyzer - One of the best experts on this subject based on the ideXlab platform.
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identification of 16s ribosomal dna defined bacterial populations at a shallow Submarine Hydrothermal Vent near milos island greece
Applied and Environmental Microbiology, 2000Co-Authors: Stefan M Sievert, Jan Kuever, Gerard MuyzerAbstract:In a recent publication (S. M. Sievert, T. Brinkhoff, G. Muyzer, W. Ziebis, and J. Kuever, Appl. Environ. Microbiol. 65:3834–3842, 1999) we described spatiotemporal changes in the bacterial community structure at a shallow-water Hydrothermal Vent in the Aegean Sea near the isle of Milos (Greece). Here we describe identification and phylogenetic analysis of the predominant bacterial populations at the Vent site and their distribution at the Vent site as determined by sequencing of DNA molecules (bands) excised from denaturing gradient gels. A total of 36 bands could be sequenced, and there were representatives of eight major lineages of the domain Bacteria. Cytophaga-Flavobacterium and Acidobacterium were the most frequently retrieved bacterial groups. Less than 33% of the sequences exhibited 90% or more identity with cultivated organisms. The predominance of putative heterotrophic populations in the sequences retrieved is explained by the input of allochthonous organic matter at the Vent site.
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spatial heterogeneity of bacterial populations along an environmental gradient at a shallow Submarine Hydrothermal Vent near milos island greece
Applied and Environmental Microbiology, 1999Co-Authors: Stefan M Sievert, Gerard Muyzer, Thorsten Brinkhoff, Wiebke Ziebis, Jan KueverAbstract:The spatial heterogeneity of bacterial populations at a shallow-water Hydrothermal Vent in the Aegean Sea close to the island of Milos (Greece) was examined at two different times by using acridine orange staining for total cell counts, cultivation-based techniques, and denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA gene fragments. Concurrent with measurements of geochemical parameters, samples were taken along a transect from the center of the Vent to the surrounding area. Most-probable-number (MPN) counts of metabolically defined subpopulations generally constituted a minor fraction of the total cell counts; both counting procedures revealed the highest cell numbers in a transition zone from the strongly Hydrothermally influenced sediments to normal sedimentary conditions. Total cell counts ranged from 3.2 x 10(5) cells ml(-1) in the water overlying the sediments to 6.4 x 10(8) cells g (wet weight) of sediment(-1). MPN counts of chemolithoautotrophic sulfur-oxidizing bacteria varied between undetectable and 1.4 x 10(6) cells g(-1). MPN counts for sulfate-reducing bacteria and dissimilatory iron-reducing bacteria ranged from 8 to 1.4 x 10(5) cells g(-1) and from undetectable to 1.4 x 10(6) cells g(-1), respectively. DGGE revealed a trend from a diverse range of bacterial populations which were present in approximately equal abundance in the transition zone to a community dominated by few populations close to the center of the Vent. Temperature was found to be an important parameter in determining this trend. However, at one sampling time this trend was not discernible, possibly due to storm-induced disturbance of the upper sediment layers.
Jan Kuever - One of the best experts on this subject based on the ideXlab platform.
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identification of 16s ribosomal dna defined bacterial populations at a shallow Submarine Hydrothermal Vent near milos island greece
Applied and Environmental Microbiology, 2000Co-Authors: Stefan M Sievert, Jan Kuever, Gerard MuyzerAbstract:In a recent publication (S. M. Sievert, T. Brinkhoff, G. Muyzer, W. Ziebis, and J. Kuever, Appl. Environ. Microbiol. 65:3834–3842, 1999) we described spatiotemporal changes in the bacterial community structure at a shallow-water Hydrothermal Vent in the Aegean Sea near the isle of Milos (Greece). Here we describe identification and phylogenetic analysis of the predominant bacterial populations at the Vent site and their distribution at the Vent site as determined by sequencing of DNA molecules (bands) excised from denaturing gradient gels. A total of 36 bands could be sequenced, and there were representatives of eight major lineages of the domain Bacteria. Cytophaga-Flavobacterium and Acidobacterium were the most frequently retrieved bacterial groups. Less than 33% of the sequences exhibited 90% or more identity with cultivated organisms. The predominance of putative heterotrophic populations in the sequences retrieved is explained by the input of allochthonous organic matter at the Vent site.
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spatial heterogeneity of bacterial populations along an environmental gradient at a shallow Submarine Hydrothermal Vent near milos island greece
Applied and Environmental Microbiology, 1999Co-Authors: Stefan M Sievert, Gerard Muyzer, Thorsten Brinkhoff, Wiebke Ziebis, Jan KueverAbstract:The spatial heterogeneity of bacterial populations at a shallow-water Hydrothermal Vent in the Aegean Sea close to the island of Milos (Greece) was examined at two different times by using acridine orange staining for total cell counts, cultivation-based techniques, and denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA gene fragments. Concurrent with measurements of geochemical parameters, samples were taken along a transect from the center of the Vent to the surrounding area. Most-probable-number (MPN) counts of metabolically defined subpopulations generally constituted a minor fraction of the total cell counts; both counting procedures revealed the highest cell numbers in a transition zone from the strongly Hydrothermally influenced sediments to normal sedimentary conditions. Total cell counts ranged from 3.2 x 10(5) cells ml(-1) in the water overlying the sediments to 6.4 x 10(8) cells g (wet weight) of sediment(-1). MPN counts of chemolithoautotrophic sulfur-oxidizing bacteria varied between undetectable and 1.4 x 10(6) cells g(-1). MPN counts for sulfate-reducing bacteria and dissimilatory iron-reducing bacteria ranged from 8 to 1.4 x 10(5) cells g(-1) and from undetectable to 1.4 x 10(6) cells g(-1), respectively. DGGE revealed a trend from a diverse range of bacterial populations which were present in approximately equal abundance in the transition zone to a community dominated by few populations close to the center of the Vent. Temperature was found to be an important parameter in determining this trend. However, at one sampling time this trend was not discernible, possibly due to storm-induced disturbance of the upper sediment layers.
