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531 results on '"Richnow, Hans H."'

101. Sulfur and Oxygen Isotope Fractionation During Bacterial Sulfur Disproportionation Under Anaerobic Haloalkaline Conditions

Author

Poser, Alexander (author), Vogt, Carsten (author), Knöller, Kay (author), Sorokin, Dimitry Y. (author), Finster, Kai W. (author), Richnow, Hans H. (author), Poser, Alexander (author), Vogt, Carsten (author), Knöller, Kay (author), Sorokin, Dimitry Y. (author), Finster, Kai W. (author), and Richnow, Hans H. (author)

Abstract

Sulfur and oxygen isotope fractionation of elemental sulfur disproportionation at anaerobic haloalkaline conditions was evaluated for the first time. Isotope enrichment factors of the strains Desulfurivibrio alkaliphilus and Dethiobacter alkaliphilus growing at pH 9 or 10 were −0.9‰ to −1‰ for sulfide (34ϵ), +3.6‰ to +4.7‰ for sulfate (34ϵ), and +3.5‰ to +7.7‰ for oxygen in sulfate (18ϵ). These values are significantly smaller compared to previously published values of sulfur disproportionators at neutral pH. We propose that this discrepancy is caused by masking effects due to preferential formation of polysulfides at high pH leading to accelerated internal sulfur turnover rates, but cannot rule out distinct isotope effects due to specific enzymatic disproportionation reactions under haloalkaline conditions. The results imply that the microbial sulfur cycle in haloalkaline environments is characterized by specific stable sulfur and oxygen isotope patterns., Accepted Author Manuscript, BT/Environmental Biotechnology

Published
2016
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102. Anaerobic Microbial Degradation of Hydrocarbons: From Enzymatic Reactions to the Environment

Author

Rabus, Ralf, Boll, Matthias, Heider, Johann, Meckenstock, Rainer U., Buckel, Wolfgang, Einsle, Oliver, Ermler, Ulrich, Golding, Bernard T., Gunsalus, Robert P., Kroneck, Peter M.H., Krüger, Martin, Lueders, Tillmann, Martins, Berta, Musat, Florin, Richnow, Hans H., Schink, Bernhard, Seifert, Jana, Szaleniec, Maciej, Treude, Tina, Ullmann, Matthias, Vogt, Carsten, von Bergen, Martin, Wilkes, Heinz, Rabus, Ralf, Boll, Matthias, Heider, Johann, Meckenstock, Rainer U., Buckel, Wolfgang, Einsle, Oliver, Ermler, Ulrich, Golding, Bernard T., Gunsalus, Robert P., Kroneck, Peter M.H., Krüger, Martin, Lueders, Tillmann, Martins, Berta, Musat, Florin, Richnow, Hans H., Schink, Bernhard, Seifert, Jana, Szaleniec, Maciej, Treude, Tina, Ullmann, Matthias, Vogt, Carsten, von Bergen, Martin, and Wilkes, Heinz

Abstract

Hydrocarbons are abundant in anoxic environments and pose biochemical challenges to their anaerobic degradation by microorganisms. Within the framework of the Priority Program 1319, investigations funded by the Deutsche Forschungsgemeinschaft on the anaerobic microbial degradation of hydrocarbons ranged from isolation and enrichment of hitherto unknown hydrocarbon-degrading anaerobic microorganisms, discovery of novel reactions, detailed studies of enzyme mechanisms and structures to process-oriented in situ studies. Selected highlights from this program are collected in this synopsis, with more detailed information provided by theme-focused reviews of the special topic issue on ‘Anaerobic biodegradation of hydrocarbons' [this issue, pp. 1-244]. The interdisciplinary character of the program, involving microbiologists, biochemists, organic chemists and environmental scientists, is best exemplified by the studies on alkyl-/arylalkylsuccinate synthases. Here, research topics ranged from in-depth mechanistic studies of archetypical toluene-activating benzylsuccinate synthase, substrate-specific phylogenetic clustering of alkyl-/arylalkylsuccinate synthases (toluene plus xylenes, p-cymene, p-cresol, 2-methylnaphthalene, n-alkanes), stereochemical and co-metabolic insights into n-alkane-activating (methylalkyl)succinate synthases to the discovery of bacterial groups previously unknown to possess alkyl-/arylalkylsuccinate synthases by means of functional gene markers and in situ field studies enabled by state-of-the-art stable isotope probing and fractionation approaches. Other topics are Mo-cofactor-dependent dehydrogenases performing O2-independent hydroxylation of hydrocarbons and alkyl side chains (ethylbenzene, p-cymene, cholesterol, n-hexadecane), degradation of p-alkylated benzoates and toluenes, glycyl radical-bearing 4-hydroxyphenylacetate decarboxylase, novel types of carboxylation reactions (for acetophenone, acetone, and potentially also benzene and, Peer Reviewed

Published
2016

107. The active microbial diversity drives ecosystem multifunctionality and is physiologically related to carbon availability in Mediterranean semi-arid soils

Author

Bastida, Felipe, primary, Torres, Irene F., additional, Moreno, José L., additional, Baldrian, Petr, additional, Ondoño, Sara, additional, Ruiz-Navarro, Antonio, additional, Hernández, Teresa, additional, Richnow, Hans H., additional, Starke, Robert, additional, García, Carlos, additional, and Jehmlich, Nico, additional

Published
2016
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114. Anaerobic Microbial Degradation of Hydrocarbons: From Enzymatic Reactions to the Environment

Author

Rabus, Ralf, primary, Boll, Matthias, additional, Heider, Johann, additional, Meckenstock, Rainer U., additional, Buckel, Wolfgang, additional, Einsle, Oliver, additional, Ermler, Ulrich, additional, Golding, Bernard T., additional, Gunsalus, Robert P., additional, Kroneck, Peter M.H., additional, Krüger, Martin, additional, Lueders, Tillmann, additional, Martins, Berta M., additional, Musat, Florin, additional, Richnow, Hans H., additional, Schink, Bernhard, additional, Seifert, Jana, additional, Szaleniec, Maciej, additional, Treude, Tina, additional, Ullmann, G. Matthias, additional, Vogt, Carsten, additional, von Bergen, Martin, additional, and Wilkes, Heinz, additional

Published
2016
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115. Physico-chemical and biological characterization of an aquifer polluted with ETBE

Author

Yves Benoit, Laure Chancerelle, Alain Dumestre, Joanna Falcao Salles, Françoise Fayolle-Guichard, Geneviève Grundmann, Martina Kyselkova, Jeanne Moriniere, Pascal PANDARD, Richnow, Hans H., Monica Rosell, IFP Energies nouvelles (IFPEN), Institut National de l'Environnement Industriel et des Risques (INERIS), SERPOL SA, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Vétérinaire de Lyon (ENVL)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique (INRA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS), Centre for Environmental Research, Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), IFP Energies nouvelles ( IFPEN ), Institut National de l'Environnement Industriel et des Risques ( INERIS ), Université Claude Bernard Lyon 1 ( UCBL ), Ecologie microbienne ( EM ), Centre National de la Recherche Scientifique ( CNRS ) -Ecole Nationale Vétérinaire de Lyon ( ENVL ) -Université Claude Bernard Lyon 1 ( UCBL ), and Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique ( INRA ) -VetAgro Sup ( VAS )

Subjects
[ SDE ] Environmental Sciences, BIOREMEDIATION, ECOTOXICITY, POLLUTION, [SDE]Environmental Sciences, [ SDV.TOX.ECO ] Life Sciences [q-bio]/Toxicology/Ecotoxicology, AQUIFER, BIODIVERSITY, [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology, HYDROCARBONS, ETHER
Abstract

International audience; Petroleum compounds and among them, gasoline, is the most massively used chemicals worldwide and, as a consequence gasoline derives compounds are the most frequently found contaminants in groundwater

Published
2010

131. Carbon and Hydrogen Stable Isotope Fractionation Associated with the Aerobic and Anaerobic Degradation of Saturated and Alkylated Aromatic Hydrocarbons.

Author

Musat, Florin, Vogt, Carsten, and Richnow, Hans H.

Subjects
STABLE isotopes, CARBON isotopes, HYDROGEN isotopes, ALKYLATION, AROMATIC compounds, BIODEGRADATION
Abstract

Saturated hydrocarbons (alkanes) and alkylated aromatic hydrocarbons are abundant environmental compounds. Hydrocarbons are primarily removed from the environment by biodegradation, a process usually associated with moderate carbon and significant hydrogen isotope fractionation allowing monitoring of biodegradation processes in the environment. Here, we review the carbon and hydrogen stable isotope fractionation associated with the cleavage of C-H bonds at alkyl chains of hydrocarbons. Propane, n -butane and ethylbenzene were used as model components for alkyl moieties of aliphatic and aromatic hydrocarbons with emphasis on the cleavage of the C-H bond without the involvement of molecular oxygen. The carbon and hydrogen isotope fractionation factors were further used to explore the diagnostic potential for characterizing the mode of bond cleavage under oxic and anoxic conditions. ? factors, calculated to correlate carbon and hydrogen fractionation, allowed to distinguish between aerobic and anaerobic biodegradation processes in the environment. [ABSTRACT FROM AUTHOR]

Published
2016
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132. Functional Gene Markers for Fumarate-Adding and Dearomatizing Key Enzymes in Anaerobic Aromatic Hydrocarbon Degradation in Terrestrial Environments.

Author

von Netzer, Frederick, Kuntze, Kevin, Vogt, Carsten, Richnow, Hans H., Boll, Matthias, and Lueders, Tillmann

Subjects
BIODEGRADATION of aromatic compounds, BISOPROLOL, ENZYMES, ANAEROBIC bacteria, BIOCHEMISTRY
Abstract

Anaerobic degradation is a key process in many environments either naturally or anthropogenically exposed to petroleum hydrocarbons. Considerable advances into the biochemistry and physiology of selected anaerobic degraders have been achieved over the last decades, especially for the degradation of aromatic hydrocarbons. However, researchers have only recently begun to explore the ecology of complex anaerobic hydrocarbon degrader communities directly in their natural habitats, as well as in complex laboratory systems using tools of molecular biology. These approaches have mainly been facilitated by the establishment of a suite of targeted marker gene assays, allowing for rapid and directed insights into the diversity as well as the identity of intrinsic degrader populations and degradation potentials established at hydrocarbon-impacted sites. These are based on genes encoding either peripheral or central key enzymes in aromatic compound breakdown, such as fumarate-adding benzylsuccinate synthases or dearomatizing aryl-coenzyme A reductases, or on aromatic ring-cleaving hydrolases. Here, we review recent advances in this field, explain the different detection methodologies applied, and discuss how the detection of site-specific catabolic gene markers has improved the understanding of processes at contaminated sites. Functional marker gene-based strategies may be vital for the development of a more elaborate population-based assessment and prediction of aromatic degradation potentials in hydrocarbon-impacted environments. [ABSTRACT FROM AUTHOR]

Published
2016
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133. Stable Isotope Probing Approaches to Study Anaerobic Hydrocarbon Degradation and Degraders.

Author

Vogt, Carsten, Lueders, Tillmann, Richnow, Hans H., Krüger, Martin, von Bergen, Martin, and Seifert, Jana

Subjects
BIODEGRADATION of aromatic compounds, STABLE isotope analysis, MICROBIAL ecology, MICROORGANISM identification, MICROBIAL biotechnology
Abstract

Stable isotope probing (SIP) techniques have become stateof- the-art in microbial ecology over the last 10 years, allowing for the targeted detection and identification of organisms, metabolic pathways and elemental fluxes active in specific processes within complex microbial communities. For studying anaerobic hydrocarbon-degrading microbial communities, four stable isotope techniques have been used so far: DNA/RNA-SIP, PLFA (phospholipid-derived fatty acids)-SIP, protein-SIP, and single-cell-SIP by nanoSIMS (nanoscale secondary ion mass spectrometry) or confocal Raman microscopy. DNA/RNA-SIP techniques are most frequently applied due to their most meaningful phylogenetic resolution. Especially using 13 C-labeled benzene and toluene as model substrates, many new hydrocarbon degraders have been identified by SIP under various electron acceptor conditions. This has extended the current perspective of the true diversity of anaerobic hydrocarbon degraders relevant in the environment. Syntrophic hydrocarbon degradation was found to be a common mechanism for various electron acceptors. Fundamental concepts and recent advances in SIP are reflected here. A discussion is presented concerning how these techniques generate direct insights into intrinsic hydrocarbon degrader populations in environmental systems and how useful they are for more integrated approaches in the monitoring of contaminated sites and for bioremediation. [ABSTRACT FROM AUTHOR]

Published
2016
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