246 results on '"Meyerdierks A"'
Search Results
202. Physical conditions of star forming sites in the S247/252 molecular complex
- Author
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Koempe, C., Joncas, G., Jan Wouterloot, and Meyerdierks, H.
- Subjects
Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,General Medicine ,Astrophysics::Galaxy Astrophysics - Abstract
By now, it is well established that massive stars form in giant molecular clouds. Numerous studies have shown that star formation, instead of being spread uniformly throughout molecular clouds, occurs in dense condensations located within these clouds. The physical conditions in these condensations are therefore critical input parameters for any theory of star formation.
203. Bacterial sulfur cycle shapes microbial communities in surface sediments of an ultramafic hydrothermal vent field
- Author
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Regina Schauer, Hans Røy, Nico Augustin, Hans-Hermann Gennerich, Marc Peters, Frank Wenzhoefer, Rudolf Amann, and Anke Meyerdierks
- Abstract
The ultramafic-hosted Logatchev hydrothermal field (LHF) is characterized by vent fluids, which are enriched in dissolved hydrogen and methane compared with fluids from basalt-hosted systems. Thick sediment layers in LHF are partly covered by characteristic white mats. In this study, these sediments were investigated in order to determine biogeochemical processes and key organisms relevant for primary production. Temperature profiling at two mat-covered sites showed a conductive heating of the sediments. Elemental sulfur was detected in the overlying mat and metal-sulfides in the upper sediment layer. Microprofiles revealed an intensive hydrogen sulfide flux from deeper sediment layers. Fluorescence in situ hybridization showed that filamentous and vibrioid, Arcobacter-related Epsilonproteobacteria dominated the overlying mats. This is in contrast to sulfidic sediments in basalt-hosted fields where mats of similar appearance are composed of large sulfur-oxidizing Gammaproteobacteria. Epsilonproteobacteria (7-21%) and Deltaproteobacteria (20-21%) were highly abundant in the surface sediment layer. The physiology of the closest cultivated relatives, revealed by comparative 16S rRNA sequence analysis, was characterized by the capability to metabolize sulfur components. High sulfate reduction rates as well as sulfide depleted in (34)S further confirmed the importance of the biogeochemical sulfur cycle. In contrast, methane was found to be of minor relevance for microbial life in mat-covered surface sediments. Our data indicate that in conductively heated surface sediments microbial sulfur cycling is the driving force for bacterial biomass production although ultramafic-hosted systems are characterized by fluids with high levels of dissolved methane and hydrogen.
204. Volkswagen's Development of the New Carbureted Exhaust Emission Concept for Model Year 1982
- Author
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Koch, Harald, primary, Meyerdierks, Dietrich, additional, and Golden, John, additional
- Published
- 1983
- Full Text
- View/download PDF
205. Limited wrist arthrodesis: A laboratory study
- Author
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Meyerdierks, Elizabeth M., primary, Mosher, John F., additional, and Werner, Frederick W., additional
- Published
- 1987
- Full Text
- View/download PDF
206. European and U.S. Engine Design Concepts After Introduction of Unleaded Fuel in Europe
- Author
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Meyerdierks, Dietrich, primary, Reinck, Ernst, additional, Urbansky, Rolf, additional, and Thomas, Ulrich, additional
- Published
- 1986
- Full Text
- View/download PDF
207. The International Urban Symposium
- Author
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Ross, Sara Meyerdierks
- Subjects
Local government ,City planning ,Municipal government - Published
- 1982
208. Nils Olav Neverdal.
- Author
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Haaverstad, Rune, Koldsland, Stein, Hagen, Ole Magnus, Kiil, Steinar, Meyerdierks, Oliver, Bjerkeset, Ottar Arild, and Viddal, Beate
- Published
- 2017
209. How to meet the press: a survival guide
- Author
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Ross, Sara Meyerdierks
- Subjects
How to Meet the Press: a Survival Guide (Book) -- Book reviews ,Books -- Book reviews ,Business ,Business, general - Published
- 1987
210. For Your Library.
- Author
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Paise, Michele Paynter, Rose, Paige, McCutcheon, Russell, Shorner-Johnson, Kevin, Bennett, Mary Lynne, Meyerdierks, Bradford H., Steele, Daniel L., Wagoner, Cynthia, Ladd, Jason S., Cangro, Richard, Zemek, Michael, Shouldice, Heather N., and Noppe, Alex
- Subjects
NONFICTION - Abstract
The article reviews books including "Constructing a Personal Orientation to Music Teaching" by Mark Robin Campbell, Linda K. Thompson, and Janet R. Barrett, "Music Education" by Thomas Rudolph and James Frankel, and "The Music Teaching Artist's Bible: Becoming a Virtuoso Educator" by Eric Booth.
- Published
- 2012
- Full Text
- View/download PDF
211. Tuscany -- The Path.
- Author
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Meyerdierks, Carsten
- Subjects
PHOTOGRAPHERS ,PHOTOGRAPHY of houses - Abstract
The article offers the insight of photographer Carsten Meyerdierks regarding his photography of a little house in Tuscany titled " Tuscany - The Path."
- Published
- 2016
212. Bjarnarhafnarfjall.
- Author
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Meyerdierks, Carsten
- Subjects
PHOTOGRAPHERS ,PHOTOGRAPHY of mountains - Abstract
The article offers the insight of photographer Carsten Meyerdierks regarding his photography of Kirkjufell mountain in Iceland titled "Bjarnarhafnarfjall."
- Published
- 2016
213. Godafoss Sunset.
- Author
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Meyerdierks, Carsten
- Subjects
PHOTOGRAPHERS ,NATURE photography - Abstract
The article offers the insight of photographer Carsten Meyerdierks regarding his photography of a waterfall in Iceland titled "Godafoss Sunset."
- Published
- 2016
214. Unbeatable Summer.
- Author
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Meyerdierks, Brad
- Subjects
MUSIC camps ,MUSIC education - Abstract
The article relates the author's best summer camp experience while attending an integrated music camp in Florida.
- Published
- 2001
215. Devil's Symphony.
- Author
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Meyerdierks, Bradford
- Subjects
DOCUMENTARY films ,FILM reviewing ,TINNITUS ,AUDIOVISUAL materials ,MAGNETIC recorders & recording - Abstract
The article reviews the documentary video recording "Devil's Symphony" about tinnitus sufferers produced by Michael Cohen.
- Published
- 2005
216. Microbial metal‐sulfide oxidation in inactive hydrothermal vent chimneys suggested by metagenomic and metaproteomic analyses.
- Author
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Meier, Dimitri V., Pjevac, Petra, Bach, Wolfgang, Markert, Stephanie, Schweder, Thomas, Jamieson, John, Petersen, Sven, Amann, Rudolf, and Meyerdierks, Anke
- Subjects
- *
PROTEOMICS , *HYDROTHERMAL vents , *METAGENOMICS , *MARINE sediments , *RADIOACTIVE dating - Abstract
Summary: Metal‐sulfides are wide‐spread in marine benthic habitats. At deep‐sea hydrothermal vents, they occur as massive sulfide chimneys formed by mineral precipitation upon mixing of reduced vent fluids with cold oxygenated sea water. Although microorganisms inhabiting actively venting chimneys and utilizing compounds supplied by the venting fluids are well studied, only little is known about microorganisms inhabiting inactive chimneys. In this study, we combined 16S rRNA gene‐based community profiling of sulfide chimneys from the Manus Basin (SW Pacific) with radiometric dating, metagenome (n = 4) and metaproteome (n = 1) analyses. Our results shed light on potential lifestyles of yet poorly characterized bacterial clades colonizing inactive chimneys. These include sulfate‐reducing Nitrospirae and sulfide‐oxidizing Gammaproteobacteria dominating most of the inactive chimney communities. Our phylogenetic analysis attributed the gammaproteobacterial clades to the recently described Woeseiaceae family and the SSr‐clade found in marine sediments around the world. Metaproteomic data identified these Gammaproteobacteria as autotrophic sulfide‐oxidizers potentially facilitating metal‐sulfide dissolution via extracellular electron transfer. Considering the wide distribution of these gammaproteobacterial clades in marine environments such as hydrothermal vents and sediments, microbially accelerated neutrophilic mineral oxidation might be a globally relevant process in benthic element cycling and a considerable energy source for carbon fixation in marine benthic habitats. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
217. On the path to Excellence: The Northshore Concert Band.
- Author
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Meyerdierks, Bradford
- Subjects
BANDS (Musical groups) ,NONFICTION - Abstract
Reviews the book "On the Path to Excellence: The Northshore Concert Band," by William Carson.
- Published
- 2004
218. Molecular ecology of deep-sea hydrothermal plumes
- Author
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Dede, Bledina, Amann, Rudolf, Meyerdierks, Anke, and Huber, Julie
- Subjects
plume ,chemolithoautotrophs ,ddc:570 ,microbial communities ,570 Life sciences ,biology ,hydrothermal vent ,niche differentiation - Abstract
Hydrothermal plumes are considered ephemeral habitats in the deep-sea and are reported to serve as hotspots for microbial biomass. The chemolithoautotrophic microbial communities form the basis of the food web in the resource-limited deep-sea and contribute to biogeochemical cycles over larger spatial scales. Despite their influence on biogeochemistry, a comprehensive analysis of microbial clades inhabiting hydrothermal plumes, their metabolism and distribution in the open-ocean is lacking. In this thesis, I investigated the communities of ten hydrothermal plumes, located in the Atlantic and Pacific oceans, originating at different depths and characterized by distinct chemical conditions. In these plumes, the dynamics and ecological function of the dominant microbial clades were investigated and ecological niches subsequently described. The first study identified and described the niches of three new SUP05 species in three sulfur rich plumes. The niche partitioning between SUP05 species was shown to be driven by depth and minor variations in environmental parameters. Based on differences in species distribution between vent sites and open-ocean, we propose that plumes serve as growth chambers for SUP05 species, from which they are released into the surrounding water. The investigation of four plumes originating from hydrothermally active volcanoes in the South Pacific Ocean elucidated a dominance of the alkane-degrading Alcanivorax. Results of our analysis, revealed a niche partitioning driven by depth and the complexity of hydrocarbons. We hypothesized that the Alcanivorax genus could be used as an indicator of environmental perturbations, such as hydrocarbon leakage from the seabed. Finally, the third study characterized the microbial community of four hydrothermal plumes in the Mid-Atlantic Ridge (MAR). The prominent taxa in these hydrogen-rich plumes were the SUP05 clade and Sulfurimonas. The high abundance of Sulfurimonas and SUP05 pointed towards a niche partitioning between the two clades, potentially driven by oxygen and hydrogen concentrations. The results of this thesis provide valuable information on the ecology of microbial communities inhabiting diverse hydrothermal plumes, their metabolisms and their ecological niches. With this, I show how we can move towards predictive ecology of plume communities. Furthermore, the data collected and analyzed from plumes in this study, considerably expands the currently available plume data and can serve as a valuable resource in future studies.
- Published
- 2022
219. Identification and activity of acetate-assimilating bacteria in diffuse fluids venting from two deep-sea hydrothermal systems.
- Author
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Winkel, Matthias, Pjevac, Petra, Kleiner, Manuel, Littmann, Sten, Meyerdierks, Anke, Amann, Rudolf, and Mußmann, Marc
- Subjects
- *
ACETATES analysis , *FLUID mechanics , *ORGANIC compounds , *MICROORGANISMS , *HETEROTROPHIC bacteria , *FLUORESCENCE in situ hybridization - Abstract
Diffuse hydrothermal fluids often contain organic compounds such as hydrocarbons, lipids, and organic acids. Microorganisms consuming these compounds at hydrothermal sites are so far only known from cultivation-dependent studies. To identify potential heterotrophs without prior cultivation, we combined microbial community analysis with short-term incubations using 13C-labeled acetate at two distinct hydrothermal systems. We followed cell growth and assimilation of 13C into single cells by nanoSIMS combined with fluorescence in situ hybridization (FISH). In 55 °C-fluids from the Menez Gwen hydrothermal system/Mid-Atlantic Ridge, a novel epsilonproteobacterial group accounted for nearly all assimilation of acetate, representing the first aerobic acetate-consuming member of the Nautiliales. In contrast, Gammaproteobacteria dominated the 13C-acetate assimilation in incubations of 37 °C-fluids from the back-arc hydrothermal system in the Manus Basin/Papua New Guinea. Here, 16S rRNA gene sequences were mostly related to mesophilic Marinobacter, reflecting the high content of seawater in these fluids. The rapid growth of microorganisms upon acetate addition suggests that acetate consumers in diffuse fluids are copiotrophic opportunists, which quickly exploit their energy sources, whenever available under the spatially and temporally highly fluctuating conditions. Our data provide first insights into the heterotrophic microbial community, catalyzing an under-investigated part of microbial carbon cycling at hydrothermal vents. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
220. Microbial lipids reveal carbon assimilation patterns on hydrothermal sulfide chimneys.
- Author
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Reeves, Eoghan P., Yoshinaga, Marcos Y., Pjevac, Petra, Goldenstein, Nadine I., Peplies, Jörg, Meyerdierks, Anke, Amann, Rudolf, Bach, Wolfgang, and Hinrichs, Kai ‐ Uwe
- Subjects
- *
MICROBIAL lipids , *HYDROTHERMAL vents , *HABITATS , *CARBON fixation , *MICROBIAL diversity , *PROTEOBACTERIA - Abstract
Sulfide 'chimneys' characteristic of seafloor hydrothermal venting are diverse microbial habitats. 13 C/12 C ratios of microbial lipids have rarely been used to assess carbon assimilation pathways on these structures, despite complementing gene- and culture-based approaches. Here, we integrate analyses of the diversity of intact polar lipids ( IPL) and their side-chain δ13 C values (δ13 Clipid) with 16S r RNA gene-based phylogeny to examine microbial carbon flow on active and inactive sulfide structures from the Manus Basin. Surficial crusts of active structures, dominated by E psilonproteobacteria, yield bacterial δ13 Clipid values higher than biomass δ13 C (total organic carbon), implicating autotrophy via the reverse tricarboxylic acid cycle. Our data also suggest δ13 Clipid values vary on individual active structures without accompanying microbial diversity changes. Temperature and/or dissolved substrate effects - likely relating to variable advective-diffusive fluxes to chimney exteriors - may be responsible for differing 13 C fractionation during assimilation. In an inactive structure, δ13 Clipid values lower than biomass δ13 C and a distinctive IPL and 16S r RNA gene diversity suggest a shift to a more diverse community and an alternate carbon assimilation pathway after venting ceases. We discuss here the potential of IPL and δ13 Clipid analyses to elucidate carbon flow in hydrothermal structures when combined with other molecular tools. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
221. Long-term results after simple versus complex stenting of coronary artery bifurcation lesions: nordic bifurcation study 5-year follow-up results.
- Author
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Maeng, Michael, Holm, Niels R, Erglis, Andrejs, Kumsars, Indulis, Niemelä, Matti, Kervinen, Kari, Jensen, Jan S, Galløe, Anders, Steigen, Terje K, Wiseth, Rune, Narbute, Inga, Gunnes, Pål, Mannsverk, Jan, Meyerdierks, Oliver, Rotevatn, Svein, Nikus, Kjell, Vikman, Saila, Ravkilde, Jan, James, Stefan, and Aarøe, Jens
- Published
- 2013
- Full Text
- View/download PDF
222. Bacterial sulfur cycling shapes microbial communities in surface sediments of an ultramafic hydrothermal vent field.
- Author
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Schauer, Regina, Røy, Hans, Augustin, Nico, Gennerich, Hans-Hermann, Peters, Marc, Wenzhoefer, Frank, Amann, Rudolf, and Meyerdierks, Anke
- Subjects
- *
SULFUR cycle , *BIOTIC communities , *SEDIMENTS , *HYDROTHERMAL vent ecology , *SULFUR bacteria , *MICROBIAL mats , *HYDROGEN sulfide , *FLUORESCENCE in situ hybridization - Abstract
Summary The ultramafic-hosted Logatchev hydrothermal field (LHF) is characterized by vent fluids, which are enriched in dissolved hydrogen and methane compared with fluids from basalt-hosted systems. Thick sediment layers in LHF are partly covered by characteristic white mats. In this study, these sediments were investigated in order to determine biogeochemical processes and key organisms relevant for primary production. Temperature profiling at two mat-covered sites showed a conductive heating of the sediments. Elemental sulfur was detected in the overlying mat and metal-sulfides in the upper sediment layer. Microprofiles revealed an intensive hydrogen sulfide flux from deeper sediment layers. Fluorescence in situ hybridization showed that filamentous and vibrioid, Arcobacter-related Epsilonproteobacteria dominated the overlying mats. This is in contrast to sulfidic sediments in basalt-hosted fields where mats of similar appearance are composed of large sulfur-oxidizing Gammaproteobacteria. Epsilonproteobacteria (7-21%) and Deltaproteobacteria (20-21%) were highly abundant in the surface sediment layer. The physiology of the closest cultivated relatives, revealed by comparative 16S rRNA sequence analysis, was characterized by the capability to metabolize sulfur components. High sulfate reduction rates as well as sulfide depleted in 34S further confirmed the importance of the biogeochemical sulfur cycle. In contrast, methane was found to be of minor relevance for microbial life in mat-covered surface sediments. Our data indicate that in conductively heated surface sediments microbial sulfur cycling is the driving force for bacterial biomass production although ultramafic-hosted systems are characterized by fluids with high levels of dissolved methane and hydrogen. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
223. Bacterial enzymes for dissimilatory sulfate reduction in a marine microbial mat (Black Sea) mediating anaerobic oxidation of methane.
- Author
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Basen, Mirko, Krüger, Martin, Milucka, Jana, Kuever, Jan, Kahnt, Jörg, Grundmann, Olav, Meyerdierks, Anke, Widdel, Friedrich, and Shima, Seigo
- Subjects
- *
BACTERIAL proteins , *SULFATE-reducing bacteria , *MICROBIAL mats , *OXIDATION , *METHANE , *ARCHAEBACTERIA , *AMINO acids , *POLYMERASE chain reaction , *SULFOTRANSFERASES - Abstract
Anaerobic oxidation of methane (AOM) with sulfate is catalysed by microbial consortia of archaea and bacteria affiliating with methanogens and sulfate-reducing Deltaproteobacteria respectively. There is evidence that methane oxidation is catalysed by enzymes related to those in methanogenesis, but the enzymes for sulfate reduction coupled to AOM have not been examined. We collected microbial mats with high AOM activity from a methane seep in the Black Sea. The mats consisted mainly of archaea of the ANME-2 group and bacteria of the Desulfosarcina-Desulfococcus group. Cell-free mat extract contained activities of enzymes involved in sulfate reduction to sulfide: ATP sulfurylase (adenylyl : sulfate transferase; Sat), APS reductase (Apr) and dissimilatory sulfite reductase (Dsr). We partially purified the enzymes by anion-exchange chromatography. The amounts obtained indicated that the enzymes are abundant in the mat, with Sat accounting for 2% of the soluble mat protein. N-terminal amino acid sequences of purified proteins suggested similarities to the corresponding enzymes of known species of sulfate-reducing bacteria. The deduced amino acid sequence of PCR-amplified genes of the Apr subunits is similar to that of Apr of the Desulfosarcina/ Desulfococcus group. These results indicate that the major enzymes involved in sulfate reduction in the Back Sea microbial mats are of bacterial origin, most likely originating from the bacterial partner in the consortium. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
224. Identification of the dominant sulfate-reducing bacterial partner of anaerobic methanotrophs of the ANME-2 clade.
- Author
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Schreiber, Lars, Holler, Thomas, Knittel, Katrin, Meyerdierks, Anke, and Amann, Rudolf
- Subjects
- *
METHANOTROPHS , *ANAEROBIC bacteria , *METHANE , *SULFATES , *PHYLOGENY - Abstract
The anaerobic oxidation of methane (AOM) with sulfate as terminal electron acceptor is mediated by consortia of methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB). Whereas three clades of ANME have been repeatedly studied with respect to phylogeny, key genes and genomic capabilities, little is known about their sulfate-reducing partner. In order to identify the partner of anaerobic methanotrophs of the ANME-2 clade, bacterial 16S rRNA gene libraries were constructed from cultures highly enriched for ANME-2a and ANME-2c in consortia with Deltaproteobacteria of the Desulfosarcina/Desulfococcus group (DSS). Phylogenetic analysis of those and publicly available sequences from AOM sites supported the hypothesis by Knittel and colleagues that the DSS partner belongs to the diverse SEEP-SRB1 cluster. Six subclusters of SEEP-SRB1, SEEP-SRB1a to SEEP-SRB1f, were proposed and specific oligonucleotide probes were designed. Using fluorescence in situ hybridization on samples from six different AOM sites, SEEP-SRB1a was identified as sulfate-reducing partner in up to 95% of total ANME-2 consortia. SEEP-SRB1a cells exhibited a rod-shaped, vibrioid, or coccoid morphology and were found to be associated with subgroups ANME-2a and ANME-2c. Moreover, SEEP-SRB1a was also detected in 8% to 23% of ANME-3 consortia in Haakon Mosby Mud Volcano sediments, previously described to be predominantly associated with SRB of the Desulfobulbus group. SEEP-SRB1a contributed to only 0.3% to 0.7% of all single cells in almost all samples indicating that these bacteria are highly adapted to a symbiotic relationship with ANME-2. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
225. Genome sequence of Desulfobacterium autotrophicum HRM2, a marine sulfate reducer oxidizing organic carbon completely to carbon dioxide.
- Author
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Strittmatter, Axel W., Liesegang, Heiko, Rabus, Ralf, Decker, Iwona, Amann, Judith, Andres, Sönke, Henne, Anke, Fricke, Wolfgang Florian, Martinez-Arias, Rosa, Bartels, Daniela, Goesmann, Alexander, Krause, Lutz, Pühler, Alfred, Klenk, Hans-Peter, Richter, Michael, Schüler, Margarete, Glöckner, Frank Oliver, Meyerdierks, Anke, Gottschalk, Gerhard, and Amann, Rudolf
- Subjects
- *
GENE mapping research , *MARINE sediment microbiology , *CARBON dioxide , *MARINE sediments , *MICROBIAL ecology , *DESULFOVIBRIO - Abstract
Sulfate-reducing bacteria (SRB) belonging to the metabolically versatile Desulfobacteriaceae are abundant in marine sediments and contribute to the global carbon cycle by complete oxidation of organic compounds. Desulfobacterium autotrophicum HRM2 is the first member of this ecophysiologically important group with a now available genome sequence. With 5.6 megabasepairs (Mbp) the genome of Db. autotrophicum HRM2 is about 2 Mbp larger than the sequenced genomes of other sulfate reducers (SRB). A high number of genome plasticity elements (> 100 transposon-related genes), several regions of GC discontinuity and a high number of repetitive elements (132 paralogous genes Mbp−1) point to a different genome evolution when comparing with Desulfovibrio spp. The metabolic versatility of Db. autotrophicum HRM2 is reflected in the presence of genes for the degradation of a variety of organic compounds including long-chain fatty acids and for the Wood–Ljungdahl pathway, which enables the organism to completely oxidize acetyl-CoA to CO2 but also to grow chemolithoautotrophically. The presence of more than 250 proteins of the sensory/regulatory protein families should enable Db. autotrophicum HRM2 to efficiently adapt to changing environmental conditions. Genes encoding periplasmic or cytoplasmic hydrogenases and formate dehydrogenases have been detected as well as genes for the transmembrane TpII- c3, Hme and Rnf complexes. Genes for subunits A, B, C and D as well as for the proposed novel subunits L and F of the heterodisulfide reductases are present. This enzyme is involved in energy conservation in methanoarchaea and it is speculated that it exhibits a similar function in the process of dissimilatory sulfate reduction in Db. autotrophicum HRM2. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
226. Clustered Genes Related to Sulfate Respiration in Uncultured Prokaryotes Support the Theory of Their Concomitant Horizontal Transfer.
- Author
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Mussmann, Marc, Richter, Michael, Lombardo, Thierry, Meyerdierks, Anke, Kuever, Jan, Kube, Michael, Glöckner, Frank Oliver, and Amann, Rudolf
- Subjects
- *
PROKARYOTES , *MARINE sediments , *SULFUR , *CARBON , *BACTERIA , *BACTERIOLOGY - Abstract
The dissimilatory reduction of sulfate is an ancient metabolic process central to today's biogeochemical cycling of sulfur and carbon in marine sediments. Until now its polyphyletic distribution was most parsimoniously explained by multiple horizontal transfers of single genes rather than by a not-yet-identified "metabolic island." Here we provide evidence that the horizontal transfer of a gene cluster may indeed be responsible for the patchy distribution of sulfate-reducing prokaryotes (SRP) in the phylogenetic tree. We isolated three DNA fragments (32 to 41 kb) from uncultured, closely related SRP from DNA directly extracted from two distinct marine sediments. Fosmid ws39f7, and partially also fosmids ws7f8 and hr42c9, harbored a core set of essential genes for the dissimilatory reduction of sulfate, including enzymes for the reduction of sulfur intermediates and synthesis of the prosthetic group of the dissimilatory sulfite reductase. Genome comparisons suggest that encoded membrane proteins universally present among SRP are critical for electron transfer to cytoplasmic enzymes. In addition, novel, conserved hypothetical proteins that are likely involved in dissimilatory sulfate reduction were identified. Based on comparative genomics and previously published experimental evidence, a more comprehensive model of dissimilatory sulfate reduction is presented. The observed clustering of genes involved in dissimilatory sulfate reduction has not been previously found. These findings strongly support the hypothesis that genes responsible for dissimilatory sulfate reduction were concomitantly transferred in a single event among prokaryotes. The acquisition of an optimized gene set would enormously facilitate a successful implementation of a novel pathway. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
227. Characterization of a Spontaneous Nonmagnetic Mutant of Magnetospirillum gryphiswaldense Reveals a Large Deletion Comprising a Putative Magnetosome Island.
- Author
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Schübbe, Sabrina, Kube, Michael, Scheffel, André, Wawer, Cathrin, Heyen, Udo, Meyerdierks, Anke, Madkour, Mohamed H., Mayer, Frank, Reinhardt, Richard, and Schür, Dirk
- Subjects
- *
MICROBIAL mutation , *BACTERIA - Abstract
Discusses the characterization of a spontaneous nonmagnetic mutant of Magnetospirillum gryphiswaldense. Deletion comprising a putative magnetosome island; Uptake and accumulation of iron; Isolation of a bacterial artificial chromosome clone.
- Published
- 2003
- Full Text
- View/download PDF
228. Molecular Ecology of Free-Living Chemoautotrophic Microbial Communities at a Shallow-sea Hydrothermal Vent
- Author
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Huang, Chia-I, Amann, Rudolf, Meyerdierks, Anke, and Bach, Wolfgang
- Subjects
metagenomics ,hydroerhmal vents ,sulfur cycle ,ddc:570 ,570 Life sciences ,biology ,microbial community ,thermophiles - Abstract
Deep-sea hydrothermal systems are unique habitats for microbial life with primary production based on chemosynthesis. They are considered to be windows to the subsurface biosphere. Their far more accessible shallow-sea counterparts are valuable targets to study the effects of hydrothermal activity on geology, seawater chemistry and microorganisms. Such an area of shallow-sea hydrothermal venting is observed approximately 2.5 km east off Panarea Island (Sicily, Italy). This system is characterized by fluid temperatures of up to 135°C, gas emissions dominated by CO2 and precipitation of elemental sulfur on the seafloor. It is quite well studied, yet, only very few studies exist on its microbial ecology. This thesis is therefore targeting the microbiology of sediment cores as part of an interdisciplinary project which combines geological, geochemical, biomarker and molecular biological investigations. It was intended to correlate the environmental parameters with the taxonomic composition and the metagenomes of the microbial community thereby gaining insights into the interaction of geosphere and biosphere. All samples were taken at Hot Lake, an oval-shaped (~10 by 6 meters) shallow (~2.5 m deep) depression at 18 m below sea level. The sediments in this depression are strongly affected by hydrothermal activity. In situ temperatures at 10 cm below sea floor of 36°C and 74°C were measured at two different sites within Hot Lake. Based on the physico-chemical parameters, a thermodynamic modeling was performed which revealed sulfur oxidation and sulfur reduction to be exergonic at Hot Lake. Microbial community structures of different sediment layers were first screened by automated rRNA intergenic spacer analysis (ARISA). Based on the ARISA fingerprints, a total of eight bacterial and archaeal 16S rRNA gene libraries were constructed from surface to bottom layers of sediments to gain more insights into microbial diversity. Comparative sequence analyses revealed a dominance of sequences affiliated with Epsilonproteobacteria, Deltaproteobacteria and Bacteroidetes. In the surface sediments, sequences close to anoxygenic phototrophic Chlorobi were also detected. In the bottom sediments, thermophilic bacteria such as Thermodesulfobacteria spp. were found. Hyperthermophilic Archaea sequences related to Desulfurococcaceae and Korarchaeota were retrieved from 74°C hot sediment. Based on the most closely related cultured representatives, it could be deduced that the majority of microorganisms in Hot Lake sediments have a sulfur-dependent metabolism, including sulfide oxidation, sulfur reduction or sulfate reduction. Fluorescence in situ hybridization showed the dominance of Bacteria in all depths of sediments. With increasing depth and temperature, the abundance of Archaea increased relatively to that of Bacteria. Metagenomic analyses revealed that Epsilonproteobacteria were dominating surface sediments of Hot Lake where they gain energy from sulfur metabolism to fix CO2 by the reductive tricarboxylic acid (rTCA) cycle. This is consistent with findings reported from deep-sea hydrothermal vent systems. The results have led to the conclusion that mixing between hydrothermal fluids and seawater results in distinctly different temperature gradients and ecological niches in Hot Lake sediments. Overall, the correlation of geochemical profiles, IPL analyses, characterization of the microbiological community and metagenomic analyses provided strong evidence for a sulfur-dominated metabolism in the surface sediments of Hot Lake.
- Published
- 2012
229. Bestimmung des genetischen Potentials von nicht-kultivierten, sulfat-reduzierenden Bakterien
- Author
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Schreiber, Lars, Amann, Rudolf, Meyerdierks, Anke, and Boetius, Antje
- Subjects
Sulfate-reduction ,metagenomics ,ddc:570 ,570 Life sciences ,biology ,anaerobic oxidation of methane ,cold seep - Abstract
The anaerobic oxidation of methane with sulfate (AOM) removes more than 90% of the methane produced in marine sediments. The process is mediated by consortia of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB). Previous studies focusing on the archaeal part of ANME/SRB consortia yielded as yet only a fragmentary understanding of this process. Additionally, whereas ANME clades have been repeatedly studied with respect to phylogeny, key genes, and genomic capabilities, little is known about their sulfate-reducing partner. Thus, in order to change this situation, this thesis focused on SRB associated with AOM.In the first part of this thesis, SRB associated with Archaea from the ANME-2 clade were investigated. Sequences of bacterial 16S rRNA genes retrieved from ANME-2/SRB enrichment cultures supported a previous hypothesis that ANME-2 associated SRB belong to the SEEP-SRB1 group within the deltaproteobacterial Desulfosarcina/Desulfococcus (DSS) group. Using fluorescence in situ hybridization (FISH) and probes for newly defined SEEP-SRB1 subgroups (a-f), bacteria from the SEEP-SRB1a subgroup were identified as the dominant sulfatereducing partners in ANME-2 consortia in samples from six different AOM sites. In contrast to their abundance as ANME-2 partners, single SEEP-SRB1a cells were very rare (
- Published
- 2010
230. Diversität und Funktion mikrobieller Gemeinschaften in Sedimenten aus verschiedenen Tiefseehabitaten
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Schauer, R., Amann, Rudolf, Meyerdierks, Anke, and Harder, Jens
- Subjects
deep sea ,ddc:570 ,570 Life sciences ,biology ,biogeography ,chemosynthesis - Abstract
Deep-sea floors are diverse environments that range from permanently cold (desert-like plains) to hot systems (hydrothermal vents). In hot systems, primary productivity is performed by microbial communities which use chemical energy generated by geological processes (lithotrophy). This energy transfer from mantle to the ocean is as yet poorly understood, and the diversity and activity of microbes at these sites is therefore an interesting target for microbial ecologists. However, the vast majority of all globally distributed deep-sea sediments is permanently cold. The distribution of microorganisms in deep-sea floors and the factors controlling it at small and large scales are important for the understanding of the mechanisms that regulate biodiversity. During this thesis, hydrothermally influenced sediments of the peridotite-hosted Logatchev hydrothermal vent field were investigated in an interdisciplinary study to reveal the diversity and activity of the associated microbial communities. In situ microprofiles showed that these sediments were controlled by diffusive transport, instead of previously reported advective processes. White mats on top of these sediments resemble Beggiatoa-mats from the basalt- hosted field in the Guaymas Basin. However, fluorescence in situ hybridization revealed that the overlying sulfur-mats were dominated by filamentous Epsilonproteobacteria or a vibrioid Arcobacter-type. The microbial community of the surface layer was predominantly composed of Epsilonproteobacteria (7-21%), Deltaproteobacteria (20-21%), and Bacteroidetes (19- 20%). Comparative 16S rRNA gene sequence analyses identified various bacteria related to those found in basaltic systems. The presence of an active microbial community in these sediment surface layers was confirmed by high oxygen consumption rates. Geochemical analyses detected metal-sulfides in the sediments, elemental sulfur in the mats and an intensive sulfide flux from below. Ex situ incubations and turnover rate experiments revealed that sulfide is consumed and that sulfate-reduction is performed by the surface sediment microbial community. This was consistent with the detection of aprA-genes and soxB-genes, which are both key genes of the sulfur cycle. Further metabolic capabilities such as denitrification and CO2-fixation were indicated by primary analysis of metagenomic data retrieved by pyrosequencing. So far, our analyses suggest that sulfur cycling is one of the driving forces for primary production and biomass formation in surface sediments of the ultramafic-hosted Logatchev hydrothermal vent fields. Therefore, major differences in microbial composition between basalt- and peridotite-hosted fields were not detected. Hydrothermally influenced sediments from the Mid-Atlantic Ridge and permanently cold sediments from three basins of the eastern South Atlantic Ocean were investigated to examine the ability of microorganisms to disperse in the deep-sea. Besides spatial distance, the structuring effect of the physical barrier Walvis Ridge, which separates the Cape Basin from the other two basins, was determined. The analysis of 16S rRNA gene sequences of the deep- sea sediments revealed phylotypes affiliated with Gammaproteobacteria, Deltaproteobacteria and Acidobacteria, which were present in all three basins. The distribution of these shared phylotypes seemed to be influenced neither by the Walvis Ridge nor by different deep water masses, suggesting a high dispersal capability, as also indicated by low distance decay relationships. In contrast, the comparison of the total bacterial diversity of the cold sediments as well as of the hydrothermally influenced sediments revealed significant differences between the microbial communities. Within the Logatchev field and therefore for small distances (3000 km), both factors influenced bacterial diversity, indicating a complex interplay of local contemporary environmental effects and dispersal limitation.
- Published
- 2010
231. TCT-318 Ten-year All-cause Mortality after Simple versus Complex Stenting of Coronary Artery Bifurcation Lesions in the Randomized Nordic Bifurcation Study.
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Steigen, Terje, Holm, Niels, Kumsars, Indulis, Niemela, Matti, James, Stefan, Erglis, Andrejs, Kervinen, Kari, Jensen, Jan Skov, Galloe, Anders Michael, Wiseth, Rune, Gunnes, Paul, Meyerdierks, Oliver, Rotevatn, Svein, Vikman, saila, Maeng, Michael, Ravkilde, Jan, Ylitalo, Antti, Helqvist, Steffen, Sjogren, Iwar, and Jensen, Lisette Okkels
- Subjects
- *
CORONARY heart disease treatment , *CORONARY artery surgery , *DRUG-eluting stents , *RAPAMYCIN , *MORTALITY - Published
- 2016
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232. Bacterial chemolithoautotrophy in ultramafic plumes along the Mid-Atlantic Ridge.
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Dede B, Reeves EP, Walter M, Bach W, Amann R, and Meyerdierks A
- Subjects
- Atlantic Ocean, Microbiota, Hydrogen metabolism, Phylogeny, Sulfur metabolism, Oxidation-Reduction, In Situ Hybridization, Fluorescence, Carbon Dioxide metabolism, Hydrothermal Vents microbiology, RNA, Ribosomal, 16S genetics, Bacteria genetics, Bacteria classification, Bacteria isolation & purification, Chemoautotrophic Growth, Seawater microbiology
- Abstract
Hydrothermal vent systems release reduced chemical compounds that act as an important energy source in the deep sea. Chemolithoautotrophic microbes inhabiting hydrothermal plumes oxidize these compounds, in particular, hydrogen and reduced sulfur, to obtain the energy required for CO2 fixation. Here, we analysed the planktonic communities of four hydrothermal systems located along the Mid-Atlantic Ridge: Irinovskoe, Semenov-2, Logatchev-1, and Ashadze-2, by combining long-read 16S rRNA gene analysis, fluorescence in situ hybridization, meta-omics, and thermodynamic calculations. Sulfurimonas and SUP05 dominated the microbial communities in these hydrothermal plumes. Investigation of Sulfurimonas and SUP05 MAGs, and their gene transcription in plumes indicated a niche partitioning driven by hydrogen and sulfur. In addition to sulfur and hydrogen oxidation, a novel SAR202 clade inhabiting the plume, here referred to as genus Carboxydicoccus, harbours the capability for CO oxidation and CO2 fixation via reverse TCA cycle. Both pathways were also highly transcribed in other hydrogen-rich plumes, including the Von Damm vent field. Carboxydicoccus profundi reached up to 4% relative abundance (1.0 x 103 cell ml- 1) in Irinovskoe non-buoyant plume and was also abundant in non-hydrothermally influenced deep-sea metagenomes (up to 5 RPKM). Therefore, CO, which is probably not sourced from the hydrothermal fluids (1.9-5.8 μM), but rather from biological activities within the rising fluid, may serve as a significant energy source in hydrothermal plumes. Taken together, this study sheds light on the chemolithoautotrophic potential of the bacterial community in Mid-Atlantic Ridge plumes., (© The Author(s) 2024. Published by Oxford University Press on behalf of the International Society for Microbial Ecology.)
- Published
- 2024
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233. High abundance of hydrocarbon-degrading Alcanivorax in plumes of hydrothermally active volcanoes in the South Pacific Ocean.
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Dede B, Priest T, Bach W, Walter M, Amann R, and Meyerdierks A
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- Pacific Ocean, In Situ Hybridization, Fluorescence, RNA, Ribosomal, 16S genetics, Hydrocarbons metabolism, Phylogeny, Seawater, Alcanivoraceae genetics, Alcanivoraceae metabolism
- Abstract
Species within the genus Alcanivorax are well known hydrocarbon-degraders that propagate quickly in oil spills and natural oil seepage. They are also inhabitants of the deep-sea and have been found in several hydrothermal plumes. However, an in-depth analysis of deep-sea Alcanivorax is currently lacking. In this study, we used multiple culture-independent techniques to analyze the microbial community composition of hydrothermal plumes in the Northern Tonga arc and Northeastern Lau Basin focusing on the autecology of Alcanivorax. The hydrothermal vents feeding the plumes are hosted in an arc volcano (Niua), a rear-arc caldera (Niuatahi) and the Northeast Lau Spreading Centre (Maka). Fluorescence in situ hybridization revealed that Alcanivorax dominated the community at two sites (1210-1565 mbsl), reaching up to 48% relative abundance (3.5 × 10
4 cells/ml). Through 16S rRNA gene and metagenome analyses, we identified that this pattern was driven by two Alcanivorax species in the plumes of Niuatahi and Maka. Despite no indication for hydrocarbon presence in the plumes of these areas, a high expression of genes involved in hydrocarbon-degradation was observed. We hypothesize that the high abundance and gene expression of Alcanivorax is likely due to yet undiscovered hydrocarbon seepage from the seafloor, potentially resulting from recent volcanic activity in the area. Chain-length and complexity of hydrocarbons, and water depth could be driving niche partitioning in Alcanivorax., (© 2023. The Author(s).)- Published
- 2023
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234. Niche differentiation of sulfur-oxidizing bacteria (SUP05) in submarine hydrothermal plumes.
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Dede B, Hansen CT, Neuholz R, Schnetger B, Kleint C, Walker S, Bach W, Amann R, and Meyerdierks A
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- Bacteria, In Situ Hybridization, Fluorescence, Oxidation-Reduction, Phylogeny, RNA, Ribosomal, 16S genetics, RNA, Ribosomal, 16S metabolism, Seawater microbiology, Sulfur metabolism, Hydrothermal Vents microbiology
- Abstract
Hydrothermal plumes transport reduced chemical species and metals into the open ocean. Despite their considerable spatial scale and impact on biogeochemical cycles, niche differentiation of abundant microbial clades is poorly understood. Here, we analyzed the microbial ecology of two bathy- (Brothers volcano; BrV-cone and northwest caldera; NWC) and a mesopelagic (Macauley volcano; McV) plumes on the Kermadec intra-oceanic arc in the South Pacific Ocean. The microbial community structure, determined by a combination of 16S rRNA gene, fluorescence in situ hybridization and metagenome analysis, was similar to the communities observed in other sulfur-rich plumes. This includes a dominance of the vent characteristic SUP05 clade (up to 22% in McV and 51% in BrV). In each of the three plumes analyzed, the community was dominated by a different yet uncultivated chemoautotrophic SUP05 species, here, provisionally named, Candidatus Thioglobus vadi (McV), Candidatus Thioglobus vulcanius (BrV-cone) and Candidatus Thioglobus plumae (BrV-NWC). Statistical analyses, genomic potential and mRNA expression profiles suggested a SUP05 niche partitioning based on sulfide and iron concentration as well as water depth. A fourth SUP05 species was present at low frequency throughout investigated plume samples and may be capable of heterotrophic or mixotrophic growth. Taken together, we propose that small variations in environmental parameters and depth drive SUP05 niche partitioning in hydrothermal plumes., (© 2022. The Author(s).)
- Published
- 2022
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235. Bacterial communities in temperate and polar coastal sands are seasonally stable.
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Miksch S, Meiners M, Meyerdierks A, Probandt D, Wegener G, Titschack J, Jensen MA, Ellrott A, Amann R, and Knittel K
- Abstract
Coastal sands are biocatalytic filters for dissolved and particulate organic matter of marine and terrestrial origin, thus, acting as centers of organic matter transformation. At high temporal resolution, we accessed the variability of benthic bacterial communities over two annual cycles at Helgoland (North Sea), and compared it with seasonality of communities in Isfjorden (Svalbard, 78°N) sediments, where primary production does not occur during winter. Benthic community structure remained stable in both, temperate and polar sediments on the level of cell counts and 16S rRNA-based taxonomy. Actinobacteriota of uncultured Actinomarinales and Microtrichales were a major group, with 8 ± 1% of total reads (Helgoland) and 31 ± 6% (Svalbard). Their high activity (frequency of dividing cells 28%) and in situ cell numbers of >10% of total microbes in Svalbard sediments, suggest Actinomarinales and Microtrichales as key heterotrophs for carbon mineralization. Even though Helgoland and Svalbard sampling sites showed no phytodetritus-driven changes of the benthic bacterial community structure, they harbored significantly different communities (p < 0.0001, r = 0.963). The temporal stability of benthic bacterial communities is in stark contrast to the dynamic succession typical of coastal waters, suggesting that pelagic and benthic bacterial communities respond to phytoplankton productivity very differently., (© 2021. The Author(s).)
- Published
- 2021
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236. Cultivation and functional characterization of 79 planctomycetes uncovers their unique biology.
- Author
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Wiegand S, Jogler M, Boedeker C, Pinto D, Vollmers J, Rivas-Marín E, Kohn T, Peeters SH, Heuer A, Rast P, Oberbeckmann S, Bunk B, Jeske O, Meyerdierks A, Storesund JE, Kallscheuer N, Lücker S, Lage OM, Pohl T, Merkel BJ, Hornburger P, Müller RW, Brümmer F, Labrenz M, Spormann AM, Op den Camp HJM, Overmann J, Amann R, Jetten MSM, Mascher T, Medema MH, Devos DP, Kaster AK, Øvreås L, Rohde M, Galperin MY, and Jogler C
- Subjects
- Bacteria classification, Bacteria cytology, Bacteria genetics, Cell Division, Ecosystem, Genetic Variation, Genome, Bacterial genetics, Phylogeny, RNA, Ribosomal, 16S genetics, Secondary Metabolism, Signal Transduction, Bacteria growth & development, Bacterial Physiological Phenomena
- Abstract
When it comes to the discovery and analysis of yet uncharted bacterial traits, pure cultures are essential as only these allow detailed morphological and physiological characterization as well as genetic manipulation. However, microbiologists are struggling to isolate and maintain the majority of bacterial strains, as mimicking their native environmental niches adequately can be a challenging task. Here, we report the diversity-driven cultivation, characterization and genome sequencing of 79 bacterial strains from all major taxonomic clades of the conspicuous bacterial phylum Planctomycetes. The samples were derived from different aquatic environments but close relatives could be isolated from geographically distinct regions and structurally diverse habitats, implying that 'everything is everywhere'. With the discovery of lateral budding in 'Kolteria novifilia' and the capability of the members of the Saltatorellus clade to divide by binary fission as well as budding, we identified previously unknown modes of bacterial cell division. Alongside unobserved aspects of cell signalling and small-molecule production, our findings demonstrate that exploration beyond the well-established model organisms has the potential to increase our knowledge of bacterial diversity. We illustrate how 'microbial dark matter' can be accessed by cultivation techniques, expanding the organismic background for small-molecule research and drug-target detection.
- Published
- 2020
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237. Horizontal acquisition of a patchwork Calvin cycle by symbiotic and free-living Campylobacterota (formerly Epsilonproteobacteria).
- Author
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Assié A, Leisch N, Meier DV, Gruber-Vodicka H, Tegetmeyer HE, Meyerdierks A, Kleiner M, Hinzke T, Joye S, Saxton M, Dubilier N, and Petersen JM
- Subjects
- Animals, Bivalvia microbiology, Carbon Cycle, Citric Acid Cycle, Epsilonproteobacteria classification, Epsilonproteobacteria genetics, Gammaproteobacteria genetics, Phylogeny, Symbiosis, Epsilonproteobacteria metabolism, Photosynthesis
- Abstract
Most autotrophs use the Calvin-Benson-Bassham (CBB) cycle for carbon fixation. In contrast, all currently described autotrophs from the Campylobacterota (previously Epsilonproteobacteria) use the reductive tricarboxylic acid cycle (rTCA) instead. We discovered campylobacterotal epibionts ("Candidatus Thiobarba") of deep-sea mussels that have acquired a complete CBB cycle and may have lost most key genes of the rTCA cycle. Intriguingly, the phylogenies of campylobacterotal CBB cycle genes suggest they were acquired in multiple transfers from Gammaproteobacteria closely related to sulfur-oxidizing endosymbionts associated with the mussels, as well as from Betaproteobacteria. We hypothesize that "Ca. Thiobarba" switched from the rTCA cycle to a fully functional CBB cycle during its evolution, by acquiring genes from multiple sources, including co-occurring symbionts. We also found key CBB cycle genes in free-living Campylobacterota, suggesting that the CBB cycle may be more widespread in this phylum than previously known. Metatranscriptomics and metaproteomics confirmed high expression of CBB cycle genes in mussel-associated "Ca. Thiobarba". Direct stable isotope fingerprinting showed that "Ca. Thiobarba" has typical CBB signatures, suggesting that it uses this cycle for carbon fixation. Our discovery calls into question current assumptions about the distribution of carbon fixation pathways in microbial lineages, and the interpretation of stable isotope measurements in the environment.
- Published
- 2020
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238. Metaproteogenomic Profiling of Microbial Communities Colonizing Actively Venting Hydrothermal Chimneys.
- Author
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Pjevac P, Meier DV, Markert S, Hentschker C, Schweder T, Becher D, Gruber-Vodicka HR, Richter M, Bach W, Amann R, and Meyerdierks A
- Abstract
At hydrothermal vent sites, chimneys consisting of sulfides, sulfates, and oxides are formed upon contact of reduced hydrothermal fluids with oxygenated seawater. The walls and surfaces of these chimneys are an important habitat for vent-associated microorganisms. We used community proteogenomics to investigate and compare the composition, metabolic potential and relative in situ protein abundance of microbial communities colonizing two actively venting hydrothermal chimneys from the Manus Basin back-arc spreading center (Papua New Guinea). We identified overlaps in the in situ functional profiles of both chimneys, despite differences in microbial community composition and venting regime. Carbon fixation on both chimneys seems to have been primarily mediated through the reverse tricarboxylic acid cycle and fueled by sulfur-oxidation, while the abundant metabolic potential for hydrogen oxidation and carbon fixation via the Calvin-Benson-Bassham cycle was hardly utilized. Notably, the highly diverse microbial community colonizing the analyzed black smoker chimney had a highly redundant metabolic potential. In contrast, the considerably less diverse community colonizing the diffusely venting chimney displayed a higher metabolic versatility. An increased diversity on the phylogenetic level is thus not directly linked to an increased metabolic diversity in microbial communities that colonize hydrothermal chimneys.
- Published
- 2018
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239. Niche partitioning of diverse sulfur-oxidizing bacteria at hydrothermal vents.
- Author
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Meier DV, Pjevac P, Bach W, Hourdez S, Girguis PR, Vidoudez C, Amann R, and Meyerdierks A
- Subjects
- Carbon Cycle, Environmental Microbiology, Genome, Bacterial, Metagenome, Oxidation-Reduction, Oxides, Phylogeny, RNA, Ribosomal, 16S genetics, Sulfur chemistry, Sulfur Compounds, Epsilonproteobacteria classification, Epsilonproteobacteria physiology, Hydrothermal Vents microbiology, Seawater microbiology, Sulfur metabolism
- Abstract
At deep-sea hydrothermal vents, primary production is carried out by chemolithoautotrophic microorganisms, with the oxidation of reduced sulfur compounds being a major driver for microbial carbon fixation. Dense and highly diverse assemblies of sulfur-oxidizing bacteria (SOB) are observed, yet the principles of niche differentiation between the different SOB across geochemical gradients remain poorly understood. In this study niche differentiation of the key SOB was addressed by extensive sampling of active sulfidic vents at six different hydrothermal venting sites in the Manus Basin, off Papua New Guinea. We subjected 33 diffuse fluid and water column samples and 23 samples from surfaces of chimneys, rocks and fauna to a combined analysis of 16S rRNA gene sequences, metagenomes and real-time in situ measured geochemical parameters. We found Sulfurovum Epsilonproteobacteria mainly attached to surfaces exposed to diffuse venting, while the SUP05-clade dominated the bacterioplankton in highly diluted mixtures of vent fluids and seawater. We propose that the high diversity within Sulfurimonas- and Sulfurovum-related Epsilonproteobacteria observed in this study derives from the high variation of environmental parameters such as oxygen and sulfide concentrations across small spatial and temporal scales.
- Published
- 2017
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240. Ubiquitous Gammaproteobacteria dominate dark carbon fixation in coastal sediments.
- Author
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Dyksma S, Bischof K, Fuchs BM, Hoffmann K, Meier D, Meyerdierks A, Pjevac P, Probandt D, Richter M, Stepanauskas R, and Mußmann M
- Subjects
- Australia, Europe, Gammaproteobacteria genetics, Gammaproteobacteria isolation & purification, Gene Expression Profiling, Geography, Metagenomics, Oceans and Seas, Oxidation-Reduction, Sequence Analysis, DNA, Carbon metabolism, Carbon Cycle, Gammaproteobacteria metabolism, Geologic Sediments microbiology, Sulfur metabolism
- Abstract
Marine sediments are the largest carbon sink on earth. Nearly half of dark carbon fixation in the oceans occurs in coastal sediments, but the microorganisms responsible are largely unknown. By integrating the 16S rRNA approach, single-cell genomics, metagenomics and transcriptomics with (14)C-carbon assimilation experiments, we show that uncultured Gammaproteobacteria account for 70-86% of dark carbon fixation in coastal sediments. First, we surveyed the bacterial 16S rRNA gene diversity of 13 tidal and sublittoral sediments across Europe and Australia to identify ubiquitous core groups of Gammaproteobacteria mainly affiliating with sulfur-oxidizing bacteria. These also accounted for a substantial fraction of the microbial community in anoxic, 490-cm-deep subsurface sediments. We then quantified dark carbon fixation by scintillography of specific microbial populations extracted and flow-sorted from sediments that were short-term incubated with (14)C-bicarbonate. We identified three distinct gammaproteobacterial clades covering diversity ranges on family to order level (the Acidiferrobacter, JTB255 and SSr clades) that made up >50% of dark carbon fixation in a tidal sediment. Consistent with these activity measurements, environmental transcripts of sulfur oxidation and carbon fixation genes mainly affiliated with those of sulfur-oxidizing Gammaproteobacteria. The co-localization of key genes of sulfur and hydrogen oxidation pathways and their expression in genomes of uncultured Gammaproteobacteria illustrates an unknown metabolic plasticity for sulfur oxidizers in marine sediments. Given their global distribution and high abundance, we propose that a stable assemblage of metabolically flexible Gammaproteobacteria drives important parts of marine carbon and sulfur cycles.
- Published
- 2016
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241. Metagenome and mRNA expression analyses of anaerobic methanotrophic archaea of the ANME-1 group.
- Author
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Meyerdierks A, Kube M, Kostadinov I, Teeling H, Glöckner FO, Reinhardt R, and Amann R
- Subjects
- Base Sequence, Cytochromes c genetics, Euryarchaeota classification, Hydrogenase genetics, Iron-Sulfur Proteins genetics, Metagenomics, Methane metabolism, Molecular Sequence Data, Oceans and Seas, Oxidation-Reduction, Euryarchaeota genetics, Euryarchaeota metabolism, Metagenome, RNA, Messenger metabolism
- Abstract
Microbial consortia mediating the anaerobic oxidation of methane with sulfate are composed of methanotrophic Archaea (ANME) and Bacteria related to sulfate-reducing Deltaproteobacteria. Cultured representatives are not available for any of the three ANME clades. Therefore, a metagenomic approach was applied to assess the genetic potential of ANME-1 archaea. In total, 3.4 Mbp sequence information was generated based on metagenomic fosmid libraries constructed directly from a methanotrophic microbial mat in the Black Sea. These sequence data represent, in 30 contigs, about 82-90% of a composite ANME-1 genome. The dataset supports the hypothesis of a reversal of the methanogenesis pathway. Indications for an assimilatory, but not for a dissimilatory sulfate reduction pathway in ANME-1, were found. Draft genome and expression analyses are consistent with acetate and formate as putative electron shuttles. Moreover, the dataset points towards downstream electron-accepting redox components different from the ones known from methanogenic archaea. Whereas catalytic subunits of [NiFe]-hydrogenases are lacking in the dataset, genes for an [FeFe]-hydrogenase homologue were identified, not yet described to be present in methanogenic archaea. Clustered genes annotated as secreted multiheme c-type cytochromes were identified, which have not yet been correlated with methanogenesis-related steps. The genes were shown to be expressed, suggesting direct electron transfer as an additional possible mode to shuttle electrons from ANME-1 to the bacterial sulfate-reducing partner.
- Published
- 2010
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242. Metagenomic approach to the study of halophages: the environmental halophage 1.
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Santos F, Meyerdierks A, Peña A, Rosselló-Mora R, Amann R, and Antón J
- Subjects
- Bacteriophages ultrastructure, Base Composition, Base Sequence, Blotting, Southern, Cluster Analysis, Codon genetics, DNA Primers genetics, Genome Components, Microscopy, Electron, Transmission, Molecular Sequence Data, Restriction Mapping, Seawater virology, Sequence Analysis, DNA, Spain, Bacteriophages genetics, Biodiversity, Genome, Viral genetics, Halobacteriaceae virology, Phylogeny, Seawater microbiology, Water Microbiology
- Abstract
Hypersaline environments, such as crystallizer ponds of solar salterns, show one of the highest concentration of viruses reported for aquatic systems. All the halophages characterized so far are isolates obtained by cultivation from described haloarchaeal species that have only low abundance in the environment. We employed a culture-independent metagenomic approach to analyse for the first time complete genomes in the halophage community and explored the in situ diversity by transmission electron microscopy and pulsed-field gel electrophoresis. We report the genomic sequence of a not yet isolated halophage (named as environmental halophage 1 'EHP-1') whose DNA was obtained from crystallizer samples with a salinity of 31%. The sequenced genome has a size of 35 kb and a G + C content around 51%. The G + C content is lower than that of previously characterized halophages. However, G + C content and codon usage in EHP-1 are similar to the recently cultivated and sequenced Haloquadratum walsbyi, the major prokaryotic component in solar salterns around the world. Forty open reading frames have been predicted, including genes that putatively code for proteins involved in DNA replication (ribonucleotide reductases, thymidylate kinase) normally found in lytic viruses.
- Published
- 2007
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243. Insights into the genomes of archaea mediating the anaerobic oxidation of methane.
- Author
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Meyerdierks A, Kube M, Lombardot T, Knittel K, Bauer M, Glöckner FO, Reinhardt R, and Amann R
- Subjects
- Amino Acid Sequence, Anaerobiosis, Archaea metabolism, Base Composition, Geologic Sediments microbiology, Molecular Sequence Data, Multigene Family, Oceans and Seas, Operon, Oregon, Oxidation-Reduction, RNA, Archaeal, RNA, Ribosomal, Russia, Sequence Alignment, Water Microbiology, Archaea genetics, Genome, Archaeal, Methane metabolism
- Abstract
The anaerobic oxidation of methane is a globally significant process which is mediated by consortia of yet uncultivated methanotrophic archaea (ANME) and sulfate-reducing bacteria. In order to gain deeper insights into genome characteristics of the different ANME groups, large-insert genomic libraries were constructed using DNA extracted from a methanotrophic microbial mat growing in the anoxic part of the Black Sea, and from sediments above gas hydrates at the Hydrate Ridge off the coast of Oregon. Analysis of these fosmid libraries with respect to archaeal 16S rRNA gene diversity revealed a single ANME-1b ribotype for the Black Sea libraries, whereas the sequences derived from the Hydrate Ridge library phylogenetically affiliated with the ANME-2a, ANME-2c and ANME-3 group. Genome walking for ANME-1b resulted in a contiguous 155 kb composite genome fragment. The comparison of a set of four genomic fragments belonging to the different ANME groups revealed differences in the rRNA operon structure and the average G+C content, with the ANME-2c contig showing the highest divergence within the set. A detailed analysis of the ANME contigs with respect to genes putatively involved in the anaerobic oxidation of methane led to the identification of: (i) a putative N5,N10-methenyltetrahydromethanopterin cyclohydrolase gene, (ii) a gene cluster supposedly encoding a novel type of heterodisulfide reductase/dehydrogenase complex and (iii) a gene cluster putatively encoding a new type of CO dehydrogenase/acetyl-CoA synthase enzyme complex.
- Published
- 2005
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244. Application of tetranucleotide frequencies for the assignment of genomic fragments.
- Author
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Teeling H, Meyerdierks A, Bauer M, Amann R, and Glöckner FO
- Subjects
- Base Composition, Databases, Genetic, Likelihood Functions, Species Specificity, Bacteria genetics, Genome, Bacterial, Genomics methods, Nucleotides genetics
- Abstract
A basic problem of the metagenomic approach in microbial ecology is the assignment of genomic fragments to a certain species or taxonomic group, when suitable marker genes are absent. Currently, the (G + C)-content together with phylogenetic information and codon adaptation for functional genes is mostly used to assess the relationship of different fragments. These methods, however, can produce ambiguous results. In order to evaluate sequence-based methods for fragment identification, we extensively compared (G + C)-contents and tetranucleotide usage patterns of 9054 fosmid-sized genomic fragments generated in silico from 118 completely sequenced bacterial genomes (40 982 931 fragment pairs were compared in total). The results of this systematic study show that the discriminatory power of correlations of tetranucleotide-derived z-scores is by far superior to that of differences in (G + C)-content and provides reasonable assignment probabilities when applied to metagenome libraries of small diversity. Using six fully sequenced fosmid inserts from a metagenomic analysis of microbial consortia mediating the anaerobic oxidation of methane (AOM), we demonstrate that discrimination based on tetranucleotide-derived z-score correlations was consistent with corresponding data from 16S ribosomal RNA sequence analysis and allowed us to discriminate between fosmid inserts that were indistinguishable with respect to their (G + C)-contents.
- Published
- 2004
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245. A conspicuous nickel protein in microbial mats that oxidize methane anaerobically.
- Author
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Krüger M, Meyerdierks A, Glöckner FO, Amann R, Widdel F, Kube M, Reinhardt R, Kahnt J, Böcher R, Thauer RK, and Shima S
- Subjects
- Amino Acid Sequence, Anaerobiosis, Archaeal Proteins chemistry, Bacterial Proteins chemistry, Deltaproteobacteria metabolism, Geologic Sediments chemistry, Methanosarcinales metabolism, Molecular Sequence Data, Oceans and Seas, Phylogeny, Protein Subunits chemistry, Protein Subunits metabolism, Archaeal Proteins metabolism, Bacterial Proteins metabolism, Geologic Sediments microbiology, Metalloproteins chemistry, Metalloproteins metabolism, Methane metabolism, Nickel analysis
- Abstract
Anaerobic oxidation of methane (AOM) in marine sediments is an important microbial process in the global carbon cycle and in control of greenhouse gas emission. The responsible organisms supposedly reverse the reactions of methanogenesis, but cultures providing biochemical proof of this have not been isolated. Here we searched for AOM-associated cell components in microbial mats from anoxic methane seeps in the Black Sea. These mats catalyse AOM rather than carry out methanogenesis. We extracted a prominent nickel compound displaying the same absorption spectrum as the nickel cofactor F430 of methyl-coenzyme M reductase, the terminal enzyme of methanogenesis; however, the nickel compound exhibited a higher molecular mass than F430. The apparent variant of F(430) was part of an abundant protein that was purified from the mat and that consists of three different subunits. Determined amino-terminal amino acid sequences matched a gene locus cloned from the mat. Sequence analyses revealed similarities to methyl-coenzyme M reductase from methanogenic archaea. The abundance of the nickel protein (7% of extracted proteins) in the mat suggests an important role in AOM.
- Published
- 2003
- Full Text
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246. Interferon-alpha induces nmi-IFP35 heterodimeric complex formation that is affected by the phosphorylation of IFP35.
- Author
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Zhou X, Liao J, Meyerdierks A, Feng L, Naumovski L, Bottger EC, and Omary MB
- Subjects
- Antibodies, Carrier Proteins analysis, Carrier Proteins isolation & purification, Cross-Linking Reagents, Dimerization, Fluorescent Antibody Technique, Humans, Inhibitor of Differentiation Proteins, Interferon alpha-2, Interferon-gamma pharmacology, Jurkat Cells, Kinetics, Leucine Zippers, Nuclear Proteins analysis, Nuclear Proteins isolation & purification, Phosphorylation, Protein Binding, Recombinant Proteins metabolism, Tumor Cells, Cultured, Carrier Proteins metabolism, Interferon-alpha pharmacology, Intracellular Signaling Peptides and Proteins, Nuclear Proteins metabolism
- Abstract
Nmi and IFP35 are interferon (IFN)-induced proteins. In cells treated with IFN-gamma, Nmi enhances the association of transcription co-activator CBP/p300 with signal transducer and activator of transcription proteins, and IFP35 forms a high molecular weight cytosolic complex of unknown constituents. Here we show that Nmi and IFP35 co-immunoprecipitate with an anti-keratin 19 antibody, which is due to cross-reaction of the antibody with Nmi, and suggests an Nmi-IFP35 physical association. In support of this, Nmi and IFP35 co-immunoprecipitate using anti-Nmi and anti-IFP35 antibodies, manifest enhanced colocalization as determined by immunofluorescence staining of IFN-treated cells, and form heterodimers as determined by chemical cross-linking. Nmi and IFP35 are primarily cytosolic proteins, and their interaction is increased after IFN-alpha treatment of cells as early as 1 h after exposure. Sucrose gradient sedimentation and size fractionation showed a shift of Nmi-IFP35 heterodimers toward a heavier fraction (100-200 kDa) in IFN-alpha-treated cells. This dynamic complex formation is reversed by pretreatment with okadaic acid. Two-dimensional gel analysis indicates that the IFN-induced complex formation correlates with IFP35 dephosphorylation. Our data demonstrate Nmi-IFP35 cytosolic localization and heterodimerization, and an IFN-alpha-regulated molecular event in which Nmi and IFP35 participate, reversibly and by a dephosphorylation dependent fashion, in a 100-200-kDa molecular complex formation.
- Published
- 2000
- Full Text
- View/download PDF
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