scholarly journals Comparison of Mechanisms of Alkane Metabolism under Sulfate-Reducing Conditions among Two Bacterial Isolates and a Bacterial Consortium

2006 ◽  
Vol 72 (6) ◽  
pp. 4274-4282 ◽  
Author(s):  
Amy V. Callaghan ◽  
Lisa M. Gieg ◽  
Kevin G. Kropp ◽  
Joseph M. Suflita ◽  
Lily Y. Young
Keyword(s):  
Bacterial Consortium ◽  
Gas Chromatography Mass Spectrometry ◽  
Degradation Mechanisms ◽  
Bacterial Isolates ◽  
Alkane Degradation ◽  
Tetradecanoic Acid ◽  
Mass Spectral ◽  
Sulfate Reducing ◽  
Reducing Conditions ◽  
Fumarate Addition

ABSTRACT Recent studies have demonstrated that fumarate addition and carboxylation are two possible mechanisms of anaerobic alkane degradation. In the present study, we surveyed metabolites formed during growth on hexadecane by the sulfate-reducing isolates AK-01 and Hxd3 and by a mixed sulfate-reducing consortium. The cultures were incubated with either protonated or fully deuterated hexadecane; the sulfate-reducing consortium was also incubated with [1,2-13C2]hexadecane. All cultures were extracted, silylated, and analyzed by gas chromatography-mass spectrometry. We detected a suite of metabolites that support a fumarate addition mechanism for hexadecane degradation by AK-01, including methylpentadecylsuccinic acid, 4-methyloctadecanoic acid, 4-methyloctadec-2,3-enoic acid, 2-methylhexadecanoic acid, and tetradecanoic acid. By using d 34-hexadecane, mass spectral evidence strongly supporting a carbon skeleton rearrangement of the first intermediate, methylpentadecylsuccinic acid, was demonstrated for AK-01. Evidence indicating hexadecane carboxylation was not found in AK-01 extracts but was observed in Hxd3 extracts. In the mixed sulfate-reducing culture, however, metabolites consistent with both fumarate addition and carboxylation mechanisms of hexadecane degradation were detected, which demonstrates that multiple alkane degradation pathways can occur simultaneously within distinct anaerobic communities. Collectively, these findings underscore that fumarate addition and carboxylation are important alkane degradation mechanisms that may be widespread among phylogenetically and/or physiologically distinct microorganisms.

scholarly journals Anaerobic 1-Alkene Metabolism by the Alkane- and Alkene-Degrading Sulfate Reducer Desulfatibacillum aliphaticivorans Strain CV2803T

2007 ◽  
Vol 73 (24) ◽  
pp. 7882-7890 ◽  
Author(s):  
Vincent Grossi ◽  
Cristiana Cravo-Laureau ◽  
Alain Méou ◽  
Danielle Raphel ◽  
Frédéric Garzino ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Inorganic Carbon ◽  
Direct Evidence ◽  
Gas Chromatography Mass Spectrometry ◽  
Sulfate Reducing ◽  
Branched Fatty Acids ◽  
Initial Activation ◽  
Fumarate Addition ◽  
Chain Lengths ◽  
Methyl Branched Fatty Acids

ABSTRACT The alkane- and alkene-degrading, marine sulfate-reducing bacterium Desulfatibacillum aliphaticivorans strain CV2803T, known to oxidize n-alkanes anaerobically by fumarate addition at C-2, was investigated for its 1-alkene metabolism. The total cellular fatty acids of this strain were predominantly C-(even number) (C-even) when it was grown on C-even 1-alkenes and predominantly C-(odd number) (C-odd) when it was grown on C-odd 1-alkenes. Detailed analyses of those fatty acids by gas chromatography-mass spectrometry after 6- to 10-week incubations allowed the identification of saturated 2- and 4-ethyl-, 2- and 4-methyl-, and monounsaturated 4-methyl-branched fatty acids with chain lengths that correlated with those of the 1-alkene. The growth of D. aliphaticivorans on (per)deuterated 1-alkenes provided direct evidence of the anaerobic transformation of these alkenes into the corresponding 1-alcohols and into linear as well as 10- and 4-methyl-branched fatty acids. Experiments performed with [13C]bicarbonate indicated that the initial activation of 1-alkene by the addition of inorganic carbon does not occur. These results demonstrate that D. aliphaticivorans metabolizes 1-alkene by the oxidation of the double bond at C-1 and by the subterminal addition of organic carbon at both ends of the molecule [C-2 and C-(ω-1)]. The detection of ethyl-branched fatty acids from unlabeled 1-alkenes further suggests that carbon addition also occurs at C-3. Alkylsuccinates were not observed as potential initial intermediates in alkene metabolism. Based on our observations, the first pathways for anaerobic 1-alkene metabolism in an anaerobic bacterium are proposed. Those pathways indicate that diverse initial reactions of 1-alkene activation can occur simultaneously in the same strain of sulfate-reducing bacterium.

Toxicity and degradation of metal-complexed cyanide by a bacterial consortium under sulfate-reducing conditions

2004 ◽  
Vol 26 (12) ◽  
pp. 1007-1011 ◽  
Author(s):  
Zhe-Xue Quan ◽  
Jin-Woo Bae ◽  
Sung-Keun Rhee ◽  
Yong-Gyun Cho ◽  
Sung-Taik Lee
Keyword(s):  
Bacterial Consortium ◽  
Sulfate Reducing ◽  
Reducing Conditions

scholarly journals “Bacterial consortium from hydrothermal vent sediments presents electrogenic activity achieved under sulfate reducing conditions in a microbial fuel cell”

2020 ◽  
Vol 18 (2) ◽  
pp. 1189-1205
Author(s):  
Margarita Isabel Pérez-Díaz ◽  
Paola Zárate-Segura ◽  
Luis Antonio Bermeo-Fernández ◽  
Khemlal Nirmalkar ◽  
Fernando Bastida-González ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Hydrothermal Vent ◽  
Bacterial Consortium ◽  
Sulfate Reducing ◽  
Reducing Conditions

scholarly journals Community dynamics within a bacterial consortium during growth on toluene under sulfate-reducing conditions

2009 ◽  
Vol 70 (3) ◽  
pp. 586-596 ◽  
Author(s):  
Susann Müller ◽  
Carsten Vogt ◽  
Mandy Laube ◽  
Hauke Harms ◽  
Sabine Kleinsteuber
Keyword(s):  
Community Dynamics ◽  
Bacterial Consortium ◽  
Sulfate Reducing ◽  
Reducing Conditions

scholarly journals Stable Isotopic Studies of n-Alkane Metabolism by a Sulfate-Reducing Bacterial Enrichment Culture

2005 ◽  
Vol 71 (12) ◽  
pp. 8174-8182 ◽  
Author(s):  
Irene A. Davidova ◽  
Lisa M. Gieg ◽  
Mark Nanny ◽  
Kevin G. Kropp ◽  
Joseph M. Suflita
Keyword(s):  
Enrichment Culture ◽  
Initial Step ◽  
Gas Chromatography Mass Spectrometry ◽  
Resonance Spectroscopy ◽  
Sulfate Reducing ◽  
Cell Extracts ◽  
Stable Isotopic ◽  
Isotopic Studies ◽  
Fumarate Addition ◽  
Metabolism Analysis

ABSTRACT Gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy were used to study the metabolism of deuterated n-alkanes (C6 to C12) and 1-13C-labeled n-hexane by a highly enriched sulfate-reducing bacterial culture. All substrates were activated via fumarate addition to form the corresponding alkylsuccinic acid derivatives as transient metabolites. Formation of d 14-hexylsuccinic acid in cell extracts from exogenously added, fully deuterated n-hexane confirmed that this reaction was the initial step in anaerobic alkane metabolism. Analysis of resting cell suspensions amended with 1-13C-labeled n-hexane confirmed that addition of the fumarate occurred at the C-2 carbon of the parent substrate. Subsequent metabolism of hexylsuccinic acid resulted in the formation of 4-methyloctanoic acid, and 3-hydroxy-4-methyloctanoic acid was tentatively identified. We also found that 13C nuclei from 1-13C-labeled n-hexane became incorporated into the succinyl portion of the initial metabolite in a manner that indicated that 13C-labeled fumarate was formed and recycled during alkane metabolism. Collectively, the findings obtained with a sulfate-reducing culture using isotopically labeled alkanes augment and support the previously proposed pathway (H. Wilkes, R. Rabus, T. Fischer, A. Armstroff, A. Behrends, and F. Widdel, Arch. Microbiol. 177:235-243, 2002) for metabolism of deuterated n-hexane by a denitrifying bacterium.

scholarly journals Anaerobic Oxidation of n-Dodecane by an Addition Reaction in a Sulfate-Reducing Bacterial Enrichment Culture

2000 ◽  
Vol 66 (12) ◽  
pp. 5393-5398 ◽  
Author(s):  
Kevin G. Kropp ◽  
Irene A. Davidova ◽  
Joseph M. Suflita
Keyword(s):  
Addition Reaction ◽  
Enrichment Culture ◽  
Methyl Esters ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatographic Retention ◽  
Sulfate Reducing ◽  
Acid Metabolites ◽  
Fumarate Addition ◽  
Deuterium Retention ◽  
Fragmentation Patterns

ABSTRACT We identified trace metabolites produced during the anaerobic biodegradation of H26- and D26-n-dodecane by an enrichment culture that mineralizes these compounds in a sulfate-dependent fashion. The metabolites are dodecylsuccinic acids that, in the case of the perdeuterated substrate, retain all of the deuterium atoms. The deuterium retention and the gas chromatography-mass spectrometry fragmentation patterns of the derivatized metabolites suggest that they are formed by C—H or C—D addition across the double bond of fumarate. As trimethylsilyl esters, two nearly coeluting metabolites of equal abundance with nearly identical mass spectra were detected from each of H26- and D26-dodecane, but as methyl esters, only a single metabolite peak was detected for each parent substrate. An authentic standard of protonatedn-dodecylsuccinic acid that was synthesized and derivatized by the two methods had the same fragmentation patterns as the metabolites of H26-dodecane. However, the standard gave only a single peak for each ester type and gas chromatographic retention times different from those of the derivatized metabolites. This suggests that the succinyl moiety in the dodecylsuccinic acid metabolites is attached not at the terminal methyl group of the alkane but at a subterminal position. The detection of two equally abundant trimethylsilyl-esterified metabolites in culture extracts suggests that the analysis is resolving diastereomers which have the succinyl moiety located at the same subterminal carbon in two different absolute configurations. Alternatively, there may be more than one methylene group in the alkane that undergoes the proposed fumarate addition reaction, giving at least two structural isomers in equal amounts.

scholarly journals Anaerobic Degradation of Ethylbenzene by a New Type of Marine Sulfate-Reducing Bacterium

2003 ◽  
Vol 69 (2) ◽  
pp. 760-768 ◽  
Author(s):  
Olaf Kniemeyer ◽  
Thomas Fischer ◽  
Heinz Wilkes ◽  
Frank Oliver Glöckner ◽  
Friedrich Widdel
Keyword(s):  
Gulf Of California ◽  
Anaerobic Degradation ◽  
Denitrifying Bacteria ◽  
Gas Chromatography Mass Spectrometry ◽  
Rrna Gene ◽  
Cell Type ◽  
Alkane Degradation ◽  
Sulfate Reducing ◽  
Close Relationship ◽  
New Type

ABSTRACT Anaerobic degradation of the aromatic hydrocarbon ethylbenzene was studied with sulfate as the electron acceptor. Enrichment cultures prepared with marine sediment samples from different locations showed ethylbenzene-dependent reduction of sulfate to sulfide and always contained a characteristic cell type that formed gas vesicles towards the end of growth. A pure culture of this cell type, strain EbS7, was isolated from sediment from Guaymas Basin (Gulf of California). Complete mineralization of ethylbenzene coupled to sulfate reduction was demonstrated in growth experiments with strain EbS7. Sequence analysis of the 16S rRNA gene revealed a close relationship between strain EbS7 and the previously described marine sulfate-reducing strains NaphS2 and mXyS1 (similarity values, 97.6 and 96.2%, respectively), which grow anaerobically with naphthalene and m-xylene, respectively. However, strain EbS7 did not oxidize naphthalene, m-xylene, or toluene. Other compounds utilized by strain EbS7 were phenylacetate, 3-phenylpropionate, formate, n-hexanoate, lactate, and pyruvate. 1-Phenylethanol and acetophenone, the characteristic intermediates in anaerobic ethylbenzene degradation by denitrifying bacteria, neither served as growth substrates nor were detectable as metabolites by gas chromatography-mass spectrometry in ethylbenzene-grown cultures of strain EbS7. Rather, (1-phenylethyl)succinate and 4-phenylpentanoate were detected as specific metabolites in such cultures. Formation of these intermediates can be explained by a reaction sequence involving addition of the benzyl carbon atom of ethylbenzene to fumarate, carbon skeleton rearrangement of the succinate moiety (as a thioester), and loss of one carboxyl group. Such reactions are analogous to those suggested for anaerobic n-alkane degradation and thus differ from the initial reactions in anaerobic ethylbenzene degradation by denitrifying bacteria which employ dehydrogenations.

scholarly journals Multi-Oxygenated Organic Compounds in Fine Particulate Matter Collected in the Western Mediterranean Area

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 94
Author(s):  
Esther Borrás ◽  
Luis Antonio Tortajada-Genaro ◽  
Francisco Sanz ◽  
Amalia Muñoz
Keyword(s):  
Particulate Matter ◽  
Carboxylic Acids ◽  
Organic Compounds ◽  
Organic Pollutants ◽  
Mediterranean Area ◽  
Western Mediterranean ◽  
Anthropogenic Sources ◽  
Gas Chromatography Mass Spectrometry ◽  
Industrial Emissions ◽  
Tetradecanoic Acid

The chemical characterization of aerosols, especially fine organic fraction, is a relevant atmospheric challenge because their composition highly depends on localization. Herein, we studied the concentration of multi-oxygenated organic compounds in the western Mediterranean area, focusing on sources and the effect of air patterns. The organic aerosol fraction ranged 3–22% of the total organic mass in particulate matter (PM)2.5. Seventy multi-oxygenated organic pollutants were identified by gas chromatography–mass spectrometry, including n-alkanones, n-alcohols, anhydrosugars, monocarboxylic acids, dicarboxylic acids, and keto-derivatives. The highest concentrations were found for carboxylic acids, such as linoleic acid, tetradecanoic acid and, palmitic acid. Biomarkers for vegetation sources, such as levoglucosan and some fatty acids were detected at most locations. In addition, carboxylic acids from anthropogenic sources—mainly traffic and cooking—have been identified. The results indicate that the organic PM fraction in this region is formed mainly from biogenic pollutants, emitted directly by vegetation, and from the degradation products of anthropogenic and biogenic volatile organic pollutants. Moreover, the chemical profile suggested that this area is interesting for aerosol studies because several processes such as local costal breezes, industrial emissions, and desert intrusions affect fine PM composition.

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