7 results on '"Lueders, Tillmann"'
Search Results
2. Stable isotope probing of hypoxic toluene degradation at the Siklós aquifer reveals prominent role of Rhodocyclaceae.
- Author
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Táncsics, András, Szalay, Anna Róza, Farkas, Milan, Benedek, Tibor, Szoboszlay, Sándor, Szabó, István, and Lueders, Tillmann
- Subjects
AROMATIC compounds ,ORGANIC cyclic compounds ,TOLUENE ,GRAM-negative bacteria ,BACTERIA - Abstract
The availability of oxygen is often a limiting factor for the degradation of aromatic hydrocarbons in subsurface environments. However, while both aerobic and anaerobic degraders have been intensively studied, degradation betwixt, under micro- or hypoxic conditions has rarely been addressed. It is speculated that in environments with limited, but sustained oxygen supply, such as in the vicinity of groundwater monitoring wells, hypoxic degradation may take place. A large diversity of subfamily I.2.C extradiol dioxygenase genes has been previously detected in a BTEX-contaminated aquifer in Hungary. Older literature suggests that such catabolic potentials could be associated to hypoxic degradation. Bacterial communities dominated by members of the Rhodocyclaceae were found, but the majority of the detected C23O genotypes could not be affiliated to any known bacterial degrader lineages. To address this, a stable isotope probing (SIP) incubation of site sediments with 13C7-toluene was performed under microoxic conditions. A combination of 16S rRNA gene amplicon sequencing and T-RFLP fingerprinting of C23O genes from SIP gradient fractions revealed the central role of degraders within the Rhodocyclaceae in hypoxic toluene degradation. The main assimilators of 13C were identified as members of the genera Quatrionicoccus and Zoogloea, and a yet uncultured group of the Rhodocyclaceae. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
3. Electron acceptor-dependent identification of key anaerobic toluene degraders at a tar-oil-contaminated aquifer by Pyro-SIP.
- Author
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Pilloni, Giovanni, von Netzer, Frederick, Engel, Marion, and Lueders, Tillmann
- Subjects
ELECTROPHILES ,ANAEROBIC bacteria ,BIOAVAILABILITY ,BIODEGRADATION ,GEOCHEMISTRY ,OIL sands ,SOIL pollution ,SOIL microbiology - Abstract
Bioavailability of electron acceptors is probably the most limiting factor in the restoration of anoxic, contaminated environments. The oxidation of contaminants such as aromatic hydrocarbons, particularly in aquifers, often depends on the reduction of ferric iron or sulphate. We have previously detected a highly active fringe zone beneath a toluene plume at a tar-oil-contaminated aquifer in Germany, where a specialized community of contaminant degraders codominated by Desulfobulbaceae and Geobacteraceae had established. Although on-site geochemistry links degradation to sulphidogenic processes, dominating catabolic (benzylsuccinate synthase α-subunit, bssA) genes detected in situ appeared to be more related to those of Geobacter spp. Therefore, a stable isotope probing (SIP) incubation of sediment samples with
13 C7 -toluene and comparative electron acceptor amendment was performed. We introduce pyrosequencing of templates from SIP microcosms as a powerful new strategy in SIP gradient interpretation (Pyro-SIP). Our results reveal the central role of Desulfobulbaceae in sulphidogenic toluene degradation in situ, and affiliate the detected bssA genes to this lineage. This and the absence of13 C-labelled DNA of Geobacter spp. in SIP gradients preclude their relevance as toluene degraders in situ. In contrast, Betaproteobacteria related to Georgfuchsia spp. became labelled under iron-reducing conditions. Furthermore, secondary toluene degraders belonging to the Peptococcaceae detected in both treatments suggest the possibility of functional redundancy among anaerobic toluene degraders on site. [ABSTRACT FROM AUTHOR]- Published
- 2011
- Full Text
- View/download PDF
4. Enrichment and characterization of a sulfate-reducing toluene-degrading microbial consortium by combining in situ microcosms and stable isotope probing techniques.
- Author
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Bombach, Petra, Chatzinotas, Antonis, Neu, Thomas R., Kästner, Matthias, Lueders, Tillmann, and Vogt, Carsten
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FUNGUS-bacterium relationships ,TOLUENE ,CARBON ,SULFATES ,STABLE isotopes - Abstract
A toluene-degrading microbial consortium was enriched directly in a BTEX-contaminated aquifer under sulfate-reducing conditions using in situ microcosms consisting of toluene-loaded activated carbon pellets. Degradation of toluene and concomitant sulfide production by the consortium was subsequently demonstrated in laboratory microcosms. The consortium was physiologically and phylogenetically characterized by isotope tracer experiments using nonlabeled toluene, [
13 C]-α-toluene or [13 C7 ]-toluene as growth substrates. Cells incubated with [13 C]-α-toluene or [13 C7 ]-toluene incorporated 8–15 at.%13 C and 51–57 at.%13 C into total lipid fatty acids, respectively, indicating a lower specific incorporation of13 C from [13 C7 ]-toluene. In order to identify the toluene-assimilating bacteria, the incorporation of carbon from both [13 C]-α-toluene and [13 C7 ]-toluene into rRNA was analyzed by stable isotope probing. Time and buoyant density-resolved 16S rRNA gene-based terminal restriction fragment length polymorphism profiles, combined with cloning and sequencing, revealed that an uncultured bacterium (99% sequence similarity) related to the genus Desulfocapsa was the main toluene-degrading organism in the consortium. The ratio of the respective terminal restriction fragments changed over time, indicating trophic interactions within this consortium. [ABSTRACT FROM AUTHOR]- Published
- 2010
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5. Response and recovery of a pristine groundwater ecosystem impacted by toluene contamination – A meso-scale indoor aquifer experiment.
- Author
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Herzyk, Agnieszka, Fillinger, Lucas, Larentis, Michael, Qiu, Shiran, Maloszewski, Piotr, Hünniger, Marko, Schmidt, Susanne I., Stumpp, Christine, Marozava, Sviatlana, Knappett, Peter S.K., Elsner, Martin, Meckenstock, Rainer, Lueders, Tillmann, and Griebler, Christian
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BIODEGRADATION of toluene , *GROUNDWATER ecology , *MICROBIAL communities , *GROUNDWATER pollution , *ECOLOGICAL resilience - Abstract
Microbial communities are the driving force behind the degradation of contaminants like aromatic hydrocarbons in groundwater ecosystems. However, little is known about the response of native microbial communities to contamination in pristine environments as well as their potential to recover from a contamination event. Here, we used an indoor aquifer mesocosm filled with sandy quaternary calciferous sediment that was continuously fed with pristine groundwater to study the response, resistance and resilience of microbial communities to toluene contamination over a period of almost two years, comprising 132 days of toluene exposure followed by nearly 600 days of recovery. We observed an unexpectedly high intrinsic potential for toluene degradation, starting within the first two weeks after the first exposure. The contamination led to a shift from oxic to anoxic, primarily nitrate-reducing conditions as well as marked cell growth inside the contaminant plume. Depth-resolved community fingerprinting revealed a low resistance of the native microbial community to the perturbation induced by the exposure to toluene. Distinct populations that were dominated by a small number of operational taxonomic units (OTUs) rapidly emerged inside the plume and at the plume fringes, partially replacing the original community. During the recovery period physico-chemical conditions were restored to the pristine state within about 35 days, whereas the recovery of the biological parameters was much slower and the community composition inside the former plume area had not recovered to the original state by the end of the experiment. These results demonstrate the low resilience of sediment-associated groundwater microbial communities to organic pollution and underline that recovery of groundwater ecosystems cannot be assessed solely by physico-chemical parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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6. Biodegradation: Updating the Concepts of Control for Microbial Cleanup in Contaminated Aquifers.
- Author
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Meckenstock, Rainer U., Elsner, Martin, Griebler, Christian, Lueders, Tillmann, Stumpp, Christine, Aamand, Jens, Agathos, Spiros N., Albrechtsen, Hans-Jorgen, Bastiaens, Leen, Bjerg, Poul L., Boon, Nico, Dejonghe, Winnie, Huang, Wei E., Schmidt, Susanne I., Smolders, Erik, Sørensen, Sebastian R., Springael, Dirk, and van Breukelen, Boris M.
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CHEMICAL decomposition , *BIODEGRADATION , *BIOCHEMISTRY , *MICROBIOLOGY , *AQUIFER pollution - Abstract
The article presents information on microbial cleanup in contaminated aquifers. Topics discussed include biodegradation, organic chemicals released into the environment, and groundwater contamination. Also being discussed are whether biodegradation governed by thermodynamics, and biodegradation research.
- Published
- 2015
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7. Transcriptional response of Desulfatibacillum alkenivorans AK-01 to growth on alkanes: insights from RT-qPCR and microarray analyses
- Author
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Herath, Anjumala, Wawrik, Boris, Qin, Yujia, Zhou, Jizhong, Callaghan, Amy V, and Lueders, Tillmann
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Deltaproteobacteria ,alkane ,alkylsuccinate synthase ,Reverse Transcriptase Polymerase Chain Reaction ,Fatty Acids ,Palmitic Acid ,Bacterial ,Biological Sciences ,Medical and Health Sciences ,Microbiology ,Up-Regulation ,Environmental ,Genetic ,Gene Expression Regulation ,Alkanes ,anaerobic ,Biodegradation ,Genetics ,Environmental Pollutants ,transcription ,microarray ,Environmental Sciences ,Biotechnology - Abstract
Microbial transformation of n-alkanes in anaerobic ecosystems plays a pivotal role in biogeochemical carbon cycling and bioremediation, but the requisite genetic machinery is not well elucidated.Desulfatibacillum alkenivorans AK-01 utilizes n-alkanes (C13 to C18) and contains two genomic loci encoding alkylsuccinate synthase (ASS) gene clusters. ASS catalyzes alkane addition to fumarate to form methylalkylsuccinic acids. We hypothesized that the genes in the two clusters would be differentially expressed depending on the alkane substrate utilized for growth. RT-qPCR was used to investigate ass-gene expression across AK-01's known substrate range, and microarray-based transcriptomic analysis served to investigate whole-cell responses to growth on n-hexadecane versus hexadecanoate. RT-qPCR revealed induction of ass gene cluster 1 during growth on all tested alkane substrates, and the transcriptional start sites in cluster 1 were determined via 5'RACE. Induction of ass gene cluster 2 was not observed under the tested conditions. Transcriptomic analysis indicated that the upregulation of genes potentially involved in methylalkylsuccinate metabolism, including methylmalonyl-CoA mutase and a putative carboxyl transferase. These findings provide new directions for studying the transcriptional regulation of genes involved in alkane addition to fumarate, fumarate recycling and the processing of methylalkylsuccinates with regard to isolates, enrichment cultures and ecological datasets.
- Published
- 2016
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