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Rainer U. Meckenstock - One of the best experts on this subject based on the ideXlab platform.
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Anaerobic degradation of 1-Methylnaphthalene by a member of the Thermoanaerobacteraceae contained in an iron-reducing enrichment culture
Biodegradation, 2018Co-Authors: Sviatlana Marozava, Housna Mouttaki, Hubert Müller, Nidal Abu Laban, Alexander J. Probst, Rainer U. MeckenstockAbstract:An anaerobic culture (1MN) was enriched with 1-Methylnaphthalene as sole source of carbon and electrons and Fe(OH)_3 as electron acceptor. 1-Naphthoic acid was produced as a metabolite during growth with 1-Methylnaphthalene while 2-naphthoic acid was detected with naphthalene and 2-Methylnaphthalene. This indicates that the degradation pathway of 1-Methylnaphthalene might differ from naphthalene and 2-Methylnaphthalene degradation in sulfate reducers. Terminal restriction fragment length polymorphism and pyrosequencing revealed that the culture is mainly composed of two bacteria related to uncultured Gram-positive Thermoanaerobacteraceae and uncultured gram-negative Desulfobulbaceae . Stable isotope probing showed that a ^13C-carbon label from ^13C_10-naphthalene as growth substrate was mostly incorporated by the Thermoanaerobacteraceae . The presence of putative genes involved in naphthalene degradation in the genome of this organism was confirmed via assembly-based metagenomics and supports that it is the naphthalene-degrading bacterium in the culture. Thermoanaerobacteraceae have previously been detected in oil sludge under thermophilic conditions, but have not been shown to degrade hydrocarbons so far. The second member of the community belongs to the Desulfobulbaceae and has high sequence similarity to uncultured bacteria from contaminated sites including recently proposed groundwater cable bacteria. We suggest that the gram-positive Thermoanaerobacteraceae degrade polycyclic aromatic hydrocarbons while the Desulfobacterales are mainly responsible for Fe(III) reduction.
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combined genomic and proteomic approaches identify gene clusters involved in anaerobic 2 Methylnaphthalene degradation in the sulfate reducing enrichment culture n47
Journal of Bacteriology, 2010Co-Authors: Drazenka Selesi, Nico Jehmlich, Martin Von Bergen, Frank Schmidt, Thomas Rattei, Patrick Tischler, Tillmann Lueders, Rainer U. MeckenstockAbstract:The highly enriched deltaproteobacterial culture N47 anaerobically oxidizes the polycyclic aromatic hydrocarbons naphthalene and 2-Methylnaphthalene, with sulfate as the electron acceptor. Combined genome sequencing and liquid chromatography-tandem mass spectrometry-based shotgun proteome analyses were performed to identify genes and proteins involved in anaerobic aromatic catabolism. Proteome analysis of 2-Methylnaphthalene-grown N47 cells resulted in the identification of putative enzymes catalyzing the anaerobic conversion of 2-Methylnaphthalene to 2-naphthoyl coenzyme A (2-naphthoyl-CoA), as well as the reductive ring cleavage of 2-naphthoyl-CoA, leading to the formation of acetyl-CoA and CO(2). The glycyl radical-catalyzed fumarate addition to the methyl group of 2-Methylnaphthalene is catalyzed by naphthyl-2-methyl-succinate synthase (Nms), composed of alpha-, beta-, and gamma-subunits that are encoded by the genes nmsABC. Located upstream of nmsABC is nmsD, encoding the Nms-activating enzyme, which harbors the characteristic [Fe(4)S(4)] cluster sequence motifs of S-adenosylmethionine radical enzymes. The bns gene cluster, coding for enzymes involved in beta-oxidation reactions converting naphthyl-2-methyl-succinate to 2-naphthoyl-CoA, was found four intervening open reading frames further downstream. This cluster consists of eight genes (bnsABCDEFGH) corresponding to 8.1 kb, which are closely related to genes for enzymes involved in anaerobic toluene degradation within the denitrifiers "Aromatoleum aromaticum" EbN1, Azoarcus sp. strain T, and Thauera aromatica. Another contiguous DNA sequence harbors the gene for 2-naphthoyl-CoA reductase (ncr) and 16 additional genes that were found to be expressed in 2-Methylnaphthalene-grown cells. These genes code for enzymes that were supposed to catalyze the dearomatization and ring cleavage reactions converting 2-naphthoyl-CoA to acetyl-CoA and CO(2). Comparative sequence analysis of the four encoding subunits (ncrABCD) showed the gene product to have the closest similarity to the Azoarcus type of benzoyl-CoA reductase. The present work provides the first insight into the genetic basis of anaerobic 2-Methylnaphthalene metabolism and delivers implications for understanding contaminant degradation.
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Anaerobic degradation of 2-Methylnaphthalene by a sulfate-reducing enrichment culture.
Applied and environmental microbiology, 2000Co-Authors: Eva Annweiler, Hans H. Richnow, Andreas Kappler, Arne Materna, Michael Safinowski, Walter Michaelis, Rainer U. MeckenstockAbstract:Anaerobic degradation of 2-Methylnaphthalene was investigated with a sulfate-reducing enrichment culture. Metabolite analyses revealed two groups of degradation products. The first group comprised two succinic acid adducts which were identified as naphthyl-2-methyl-succinic acid and naphthyl-2-methylene-succinic acid by comparison with chemically synthesized reference compounds. Naphthyl-2-methyl-succinic acid accumulated to 0.5 mM in culture supernatants. Production of naphthyl-2-methyl-succinic acid was analyzed in enzyme assays with dense cell suspensions. The conversion of 2-Methylnaphthalene to naphthyl-2-methyl-succinic acid was detected at a specific activity of 0.020 6 0.003 nmol min 21 mg of protein 21 only in the presence of cells and fumarate. We conclude that under anaerobic conditions 2-Methylnaphthalene is activated by fumarate addition to the methyl group, as is the case in anaerobic toluene degradation. The second group of metabolites comprised 2-naphthoic acid and reduced 2-naphthoic acid derivatives, including 5,6,7,8-tetrahydro-2-naphthoic acid, octahydro-2-naphthoic acid, and decahydro-2-naphthoic acid. These compounds were also identified in an earlier study as products of anaerobic naphthalene degradation with the same enrichment culture. A pathway for anaerobic degradation of 2-Methylnaphthalene analogous to that for anaerobic toluene degradation is proposed.
Koichiro Tanigami - One of the best experts on this subject based on the ideXlab platform.
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characterization of toluene and 2 Methylnaphthalene transport separated by syndiotactic polystyrene having various crystalline forms
Polymer Journal, 2013Co-Authors: Koichiro Tanigami, Daisuke Ishii, Takahiko Nakaoki, Pieter StroeveAbstract:Transport of toluene or 2-Methylnaphthalene through nanoporous syndiotactic polystyrene (sPS) film. The δe-sPS was used as a film for transport measurement of toluene or 2-methynaphthalene in hexane. These solutes basically transport in the non-crystalline regions of the polystyrene. The δe-sPS crystal is characterized by the nanopore in the unit cell, which is enough space for toluene to transport, but 2-Methylnaphthalene is too large to transport in the pore. This results in low flux of 2-Methylnaphthalene in the δe-sPS film.
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Characterization of toluene and 2-Methylnaphthalene transport separated by syndiotactic polystyrene having various crystalline forms
Polymer Journal, 2013Co-Authors: Koichiro Tanigami, Daisuke Ishii, Takahiko Nakaoki, Pieter StroeveAbstract:Transport of toluene or 2-Methylnaphthalene through nanoporous syndiotactic polystyrene (sPS) film. The δ_e-sPS was used as a film for transport measurement of toluene or 2-methynaphthalene in hexane. These solutes basically transport in the non-crystalline regions of the polystyrene. The δ_e-sPS crystal is characterized by the nanopore in the unit cell, which is enough space for toluene to transport, but 2-Methylnaphthalene is too large to transport in the pore. This results in low flux of 2-Methylnaphthalene in the δ_e-sPS film. Diffusion of toluene and 2-Methylnaphthalene, in hexane solutions, through amorphous, δ_e and β films of syndiotactic polystyrene (sPS) is investigated. The diffusivity for the transport of toluene (amorphous>δ_e-sPS>β-sPS) is inversely proportional to the crystallinity. Flux in the non-crystalline region ( ) for the amorphous and δ_e-sPS films are similar, and greater than for the β-sPS film, because crystallization is promoted in the amorphous film during transport measurements. Nanopores in crystalline δ_e-sPS act as tunnels for the transport of toluene, whereas there are no such structures for β-sPS; and thus, the toluene flux is slower. The transport of 2-methynaphthalene is much slower in comparison to toluene, which can be attributed to molecular size. The diffusivity in the amorphous film is slightly larger than that for the δ_e-sPS, whereas no diffusion is observed in the β-sPS film because of the presence of deformed noncrystalline chains resulting from the high crystallinity. The for the amorphous film is larger than that for the δ_e-sPS film, because the pores in the δ_e-sPS are of insufficient size for the transport of 2-methynaphthalene.
Pieter Stroeve - One of the best experts on this subject based on the ideXlab platform.
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characterization of toluene and 2 Methylnaphthalene transport separated by syndiotactic polystyrene having various crystalline forms
Polymer Journal, 2013Co-Authors: Koichiro Tanigami, Daisuke Ishii, Takahiko Nakaoki, Pieter StroeveAbstract:Transport of toluene or 2-Methylnaphthalene through nanoporous syndiotactic polystyrene (sPS) film. The δe-sPS was used as a film for transport measurement of toluene or 2-methynaphthalene in hexane. These solutes basically transport in the non-crystalline regions of the polystyrene. The δe-sPS crystal is characterized by the nanopore in the unit cell, which is enough space for toluene to transport, but 2-Methylnaphthalene is too large to transport in the pore. This results in low flux of 2-Methylnaphthalene in the δe-sPS film.
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Characterization of toluene and 2-Methylnaphthalene transport separated by syndiotactic polystyrene having various crystalline forms
Polymer Journal, 2013Co-Authors: Koichiro Tanigami, Daisuke Ishii, Takahiko Nakaoki, Pieter StroeveAbstract:Transport of toluene or 2-Methylnaphthalene through nanoporous syndiotactic polystyrene (sPS) film. The δ_e-sPS was used as a film for transport measurement of toluene or 2-methynaphthalene in hexane. These solutes basically transport in the non-crystalline regions of the polystyrene. The δ_e-sPS crystal is characterized by the nanopore in the unit cell, which is enough space for toluene to transport, but 2-Methylnaphthalene is too large to transport in the pore. This results in low flux of 2-Methylnaphthalene in the δ_e-sPS film. Diffusion of toluene and 2-Methylnaphthalene, in hexane solutions, through amorphous, δ_e and β films of syndiotactic polystyrene (sPS) is investigated. The diffusivity for the transport of toluene (amorphous>δ_e-sPS>β-sPS) is inversely proportional to the crystallinity. Flux in the non-crystalline region ( ) for the amorphous and δ_e-sPS films are similar, and greater than for the β-sPS film, because crystallization is promoted in the amorphous film during transport measurements. Nanopores in crystalline δ_e-sPS act as tunnels for the transport of toluene, whereas there are no such structures for β-sPS; and thus, the toluene flux is slower. The transport of 2-methynaphthalene is much slower in comparison to toluene, which can be attributed to molecular size. The diffusivity in the amorphous film is slightly larger than that for the δ_e-sPS, whereas no diffusion is observed in the β-sPS film because of the presence of deformed noncrystalline chains resulting from the high crystallinity. The for the amorphous film is larger than that for the δ_e-sPS film, because the pores in the δ_e-sPS are of insufficient size for the transport of 2-methynaphthalene.
Ralf Rabus - One of the best experts on this subject based on the ideXlab platform.
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anaerobic degradation of naphthalene and 2 Methylnaphthalene by strains of marine sulfate reducing bacteria
Environmental Microbiology, 2009Co-Authors: Florin Musat, Alexander Galushko, Jacob H. Jacob, Friedrich Widdel, Michael Kube, Richard Reinhardt, Heinz Wilkes, Bernhard Schink, Ralf RabusAbstract:Summary The anaerobic biodegradation of naphthalene, an aromatic hydrocarbon in tar and petroleum, has been repeatedly observed in environments but scarcely in pure cultures. To further explore the relationships and physiology of anaerobic naphthalene-degrading microorganisms, sulfate-reducing bacteria (SRB) were enriched from a Mediterranean sediment with added naphthalene. Two strains (NaphS3, NaphS6) with oval cells were isolated which showed naphthalene-dependent sulfate reduction. According to 16S rRNA gene sequences, both strains were Deltaproteobacteria and closely related to each other and to a previously described naphthalene-degrading sulfate-reducing strain (NaphS2) from a North Sea habitat. Other close relatives were SRB able to degrade alkylbenzenes, and phylotypes enriched anaerobically with benzene. If in adaptation experiments the three naphthalene-grown strains were exposed to 2-Methylnaphthalene, this compound was utilized after a pronounced lag phase, indicating that naphthalene did not induce the capacity for 2-Methylnaphthalene degradation. Comparative denaturing gel electrophoresis of cells grown with naphthalene or 2-Methylnaphthalene revealed a striking protein band which was only present upon growth with the latter substrate. Peptide sequences from this band perfectly matched those of a protein predicted from genomic libraries of the strains. Sequence similarity (50% identity) of the predicted protein to the large subunit of the toluene-activating enzyme (benzylsuccinate synthase) from other anaerobic bacteria indicated that the detected protein is part of an analogous 2-Methylnaphthalene-activating enzyme. The absence of this protein in naphthalene-grown cells together with the adaptation experiments as well as isotopic metabolite differentiation upon growth with a mixture of d8-naphthalene and unlabelled 2-Methylnaphthalene suggest that the marine strains do not metabolize naphthalene by initial methylation via 2-Methylnaphthalene, a previously suggested mechanism. The inability to utilize 1-naphthol or 2-naphthol also excludes these compounds as free intermediates. Results leave open the possibility of naphthalene carboxylation, another previously suggested activation mechanism.
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Anaerobic degradation of naphthalene and 2‐Methylnaphthalene by strains of marine sulfate‐reducing bacteria
Environmental microbiology, 2008Co-Authors: Florin Musat, Alexander Galushko, Jacob H. Jacob, Friedrich Widdel, Michael Kube, Richard Reinhardt, Heinz Wilkes, Bernhard Schink, Ralf RabusAbstract:Summary The anaerobic biodegradation of naphthalene, an aromatic hydrocarbon in tar and petroleum, has been repeatedly observed in environments but scarcely in pure cultures. To further explore the relationships and physiology of anaerobic naphthalene-degrading microorganisms, sulfate-reducing bacteria (SRB) were enriched from a Mediterranean sediment with added naphthalene. Two strains (NaphS3, NaphS6) with oval cells were isolated which showed naphthalene-dependent sulfate reduction. According to 16S rRNA gene sequences, both strains were Deltaproteobacteria and closely related to each other and to a previously described naphthalene-degrading sulfate-reducing strain (NaphS2) from a North Sea habitat. Other close relatives were SRB able to degrade alkylbenzenes, and phylotypes enriched anaerobically with benzene. If in adaptation experiments the three naphthalene-grown strains were exposed to 2-Methylnaphthalene, this compound was utilized after a pronounced lag phase, indicating that naphthalene did not induce the capacity for 2-Methylnaphthalene degradation. Comparative denaturing gel electrophoresis of cells grown with naphthalene or 2-Methylnaphthalene revealed a striking protein band which was only present upon growth with the latter substrate. Peptide sequences from this band perfectly matched those of a protein predicted from genomic libraries of the strains. Sequence similarity (50% identity) of the predicted protein to the large subunit of the toluene-activating enzyme (benzylsuccinate synthase) from other anaerobic bacteria indicated that the detected protein is part of an analogous 2-Methylnaphthalene-activating enzyme. The absence of this protein in naphthalene-grown cells together with the adaptation experiments as well as isotopic metabolite differentiation upon growth with a mixture of d8-naphthalene and unlabelled 2-Methylnaphthalene suggest that the marine strains do not metabolize naphthalene by initial methylation via 2-Methylnaphthalene, a previously suggested mechanism. The inability to utilize 1-naphthol or 2-naphthol also excludes these compounds as free intermediates. Results leave open the possibility of naphthalene carboxylation, another previously suggested activation mechanism.
Yusuke Shimoyama - One of the best experts on this subject based on the ideXlab platform.
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Phase equilibria for the [{water+1-Methylnaphthalene+ p -xylene}] system at T =(573, 623 and 653)K
The Journal of Chemical Thermodynamics, 2013Co-Authors: Masaki Togo, Taisuke Maeda, Akira Ito, Yusuke ShimoyamaAbstract:Abstract Phase equilibria for the [{water + 1-Methylnaphthalene + p -xylene}] ternary system at T = (573, 623 and 653) K and (4.2 to 20.7) MPa were measured by a flow method. The phase equilibrium measurements were carried out with change of the feed mole fraction of 1-Methylnaphthalene in pure water from 0.25 to 0.75. The two phase region of the vapour–liquid equilibria is expanded by increasing the feed mole fraction of 1-Methylnaphthalene in pure water. The vapour–liquid–liquid equilibria were found at T = 573 K unlike the (water + p -xylene) binary system. It is found that the type of phase behaviour for the (water + 1-Methylnaphthalene + p -xylene) ternary system measured in this work is similar to that for the (water + 1-Methylnaphthalene) binary system rather than that for the (water + p -xylene) binary system.
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Phase transitions on (liquid + liquid) equilibria for (water + 1-Methylnaphthalene + light aromatic hydrocarbon) ternary systems at T = (563, 573, and 583) K
The Journal of Chemical Thermodynamics, 2012Co-Authors: Masaki Togo, Yoshiki Inamori, Yusuke ShimoyamaAbstract:Abstract Phase transitions for (water + 1-Methylnaphthalene + light aromatic hydrocarbon) ternary systems are observed at their (liquid + liquid) equilibria at T = (563, 573, and 583) K and (8.6 to 25.0) MPa. The phase transition pressures at T = (563, 573, and 583) K were measured for the five species of light aromatic hydrocarbons, o -, m -, p -xylenes, ethylbenzene, and mesitylene. The measurements of the phase transition pressures were carried out by changing the feed mole fraction of water and 1-Methylnaphthalene in water free, respectively. Effects of the feed mole fraction of water on the phase transition pressures are very small. Increasing the feed mole fraction of 1-Methylnaphthalene results in decreasing the phase transition pressures at constant temperature. The slopes depending on the feed mole fraction for 1-Methylnaphthalene at the phase transition pressures are decreased with increasing temperature for (water + 1-Methylnaphthalene + p -xylene), (water + 1-Methylnaphthalene + o -xylene), and (water + 1-Methylnaphthalene + mesitylene) systems. For xylene isomers, the highest and lowest of the phase transition pressures are obtained in the case of p - and o -xylenes, respectively. The phase transition pressures for ethylbenzene are lower than those in the case of p -xylene. The similar phase transition pressures are given for p -xylene and mesitylene.