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9 result(s) for "Jaekel, Ulrike"
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Anaerobic oxidation of ethane by archaea from a marine hydrocarbon seep
Ethane is the second most abundant component of natural gas in addition to methane, and—similar to methane—is chemically unreactive. The biological consumption of ethane under anoxic conditions was suggested by geochemical profiles at marine hydrocarbon seeps 1 – 3 , and through ethane-dependent sulfate reduction in slurries 4 – 7 . Nevertheless, the microorganisms and reactions that catalyse this process have to date remained unknown 8 . Here we describe ethane-oxidizing archaea that were obtained by specific enrichment over ten years, and analyse these archaea using phylogeny-based fluorescence analyses, proteogenomics and metabolite studies. The co-culture, which oxidized ethane completely while reducing sulfate to sulfide, was dominated by an archaeon that we name ‘ Candidatus Argoarchaeum ethanivorans’; other members were sulfate-reducing Deltaproteobacteria. The genome of Ca . Argoarchaeum contains all of the genes that are necessary for a functional methyl-coenzyme M reductase, and all subunits were detected in protein extracts. Accordingly, ethyl-coenzyme M (ethyl-CoM) was identified as an intermediate by liquid chromatography–tandem mass spectrometry. This indicated that Ca . Argoarchaeum initiates ethane oxidation by ethyl-CoM formation, analogous to the recently described butane activation by ‘ Candidatus Syntrophoarchaeum’ 9 . Proteogenomics further suggests that oxidation of intermediary acetyl-CoA to CO 2 occurs through the oxidative Wood–Ljungdahl pathway. The identification of an archaeon that uses ethane (C 2 H 6 ) fills a gap in our knowledge of microorganisms that specifically oxidize members of the homologous alkane series (C n H 2 n +2 ) without oxygen. Detection of phylogenetic and functional gene markers related to those of Ca . Argoarchaeum at deep-sea gas seeps 10 – 12 suggests that archaea that are able to oxidize ethane through ethyl-CoM are widespread members of the local communities fostered by venting gaseous alkanes around these seeps. An archaeon, ‘ Candidatus Argoarchaeum ethanivorans’, which is involved in the oxidation of ethane observed in anoxic marine habitats, is identified and metabolically characterized.
Microbial decomposition of marine dissolved organic matter in cool oceanic crust
Marine dissolved organic carbon (DOC) is one of the largest active reservoirs of reduced carbon on Earth. In the deep ocean, DOC has been described as biologically recalcitrant and has a radiocarbon age of 4,000 to 6,000 years, which far exceeds the timescale of ocean overturning. However, abiotic removal mechanisms cannot account for the full magnitude of deep-ocean DOC loss. Deep-ocean water circulates at low temperatures through volcanic crust on ridge flanks, but little is known about the associated biogeochemical processes and carbon cycling. Here we present analyses of DOC in fluids from two borehole observatories installed in crustal rocks west of the Mid-Atlantic Ridge, and show that deep-ocean DOC is removed from these cool circulating fluids. The removal mechanism is isotopically selective and causes a shift in specific features of molecular composition, consistent with microbe-mediated oxidation. We suggest organic molecules with an average radiocarbon age of 3,200 years are bioavailable to crustal microbes, and that this removal mechanism may account for at least 5% of the global loss of DOC in the deep ocean. Cool crustal circulation probably contributes to maintaining the deep ocean as a reservoir of ‘aged’ and refractory DOC by discharging the surviving organic carbon constituents that are molecularly degraded and depleted in 14C and 13C into the deep ocean.
Anaerobic degradation of propane and butane by sulfate-reducing bacteria enriched from marine hydrocarbon cold seeps
The short-chain, non-methane hydrocarbons propane and butane can contribute significantly to the carbon and sulfur cycles in marine environments affected by oil or natural gas seepage. In the present study, we enriched and identified novel propane and butane-degrading sulfate reducers from marine oil and gas cold seeps in the Gulf of Mexico and Hydrate Ridge. The enrichment cultures obtained were able to degrade simultaneously propane and butane, but not other gaseous alkanes. They were cold-adapted, showing highest sulfate-reduction rates between 16 and 20 °C. Analysis of 16S rRNA gene libraries, followed by whole-cell hybridizations with sequence-specific oligonucleotide probes showed that each enrichment culture was dominated by a unique phylotype affiliated with the Desulfosarcina-Desulfococcus cluster within the Deltaproteobacteria . These phylotypes formed a distinct phylogenetic cluster of propane and butane degraders, including sequences from environments associated with hydrocarbon seeps. Incubations with 13 C-labeled substrates, hybridizations with sequence-specific probes and nanoSIMS analyses showed that cells of the dominant phylotypes were the first to become enriched in 13 C, demonstrating that they were directly involved in hydrocarbon degradation. Furthermore, using the nanoSIMS data, carbon assimilation rates were calculated for the dominant cells in each enrichment culture.
A distinct and active bacterial community in cold oxygenated fluids circulating beneath the western flank of the Mid-Atlantic ridge
The rock-hosted, oceanic crustal aquifer is one of the largest ecosystems on Earth, yet little is known about its indigenous microorganisms. Here we provide the first phylogenetic and functional description of an active microbial community residing in the cold oxic crustal aquifer. Using subseafloor observatories, we recovered crustal fluids and found that the geochemical composition is similar to bottom seawater, as are cell abundances. However, based on relative abundances and functional potential of key bacterial groups, the crustal fluid microbial community is heterogeneous and markedly distinct from seawater. Potential rates of autotrophy and heterotrophy in the crust exceeded those of seawater, especially at elevated temperatures (25 °C) and deeper in the crust. Together, these results reveal an active, distinct, and diverse bacterial community engaged in both heterotrophy and autotrophy in the oxygenated crustal aquifer, providing key insight into the role of microbial communities in the ubiquitous cold dark subseafloor biosphere.
Author Correction: A distinct and active bacterial community in cold oxygenated fluids circulating beneath the western flank of the Mid-Atlantic ridge
An amendment to this paper has been published and can be accessed via a link at the top of the paper.An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Implementation of health-related quality of life in the German TraumaRegister DGU® – first results of a pilot study
Background Approximately 30,000 people are affected by severe injuries in Germany each year. Continuous progress in prehospital and hospital care has significantly reduced the mortality of polytrauma patients. With increasing survival rates, the functional outcome, health-related quality (hrQoL) of life and ability to work are now gaining importance. Aim of the study is, the presentation of the response behavior of seriously injured patients on the one hand and the examination of the factors influencing the quality of life and ability to work 12 months after major trauma on the other hand. Building on these initial results, a standard outcome tool shall be integrated in the established TraumaRegister DGU® in the future. Methods In 2018, patients [Injury Severity Score (ISS) ≥ 16; age:18–75 years] underwent multicenter one-year posttraumatic follow-up in six study hospitals. In addition to assessing hrQoL by using the Short-Form Health Survey (SF-12), five additional questions (treatment satisfaction; ability to work; trauma-related medical treatment; relevant physical disability, hrQoL as compared with the prior to injury status) were applied. Results Of the 1,162 patients contacted, 594 responded and were included in the analysis. The post-injury hrQoL does not show statistically significant differences between the sexes. Regarding age, however, the younger the patient at injury, the better the SF-12 physical sum score. Furthermore, the physically perceived quality of life decreases statistically significantly in relation to the severity of the trauma as measured by the ISS, whereas the mentally perceived quality of life shows no differences in terms of injury severity. A large proportion of severely injured patients were very satisfied (42.2%) or satisfied (39.9%) with the treatment outcome. It should be emphasized that patients with a high injury severity (ISS > 50) were on average more often very satisfied with the treatment outcome (46.7%). A total of 429 patients provided information on their ability to work 12 months post-injury. Here, 194 (45.2%) patients had a full employment, and 58 (13.5%) patients were had a restricted employment. Conclusion The present results show the importance of a structured assessment of the postinjury hrQoL and the ability to work after polytrauma. Further studies on the detection of influenceable risk factors on hrQoL and ability to work in the intersectoral course of treatment should follow to enable the best possible outcome of polytrauma survivors.
Generation of in silico predicted coxsackievirus B3-derived MHC class I epitopes by proteasomes
Proteasomes are known to be the main suppliers of MHC class I (MHC-I) ligands. In an attempt to identify coxsackievirus B3 (CVB3)-MHC-I epitopes, a combined approach of in silico MHC-I/transporters associated with antigen processing (TAP)-binding and proteasomal cleavage prediction was applied. Accordingly, 13 potential epitopes originating from the structural and non-structural protein region of CVB3 were selected for further in vitro processing analysis by proteasomes. Mass spectrometry demonstrated the generation of seven of the 13 predicted MHC-I ligands or respective ligand precursors by proteasomes. Detailed processing analysis of three adjacent MHC-I ligands with partially overlapping sequences, i.e. VP2(273–281), VP2(284–292) and VP2(285–293), revealed the preferential generation predominantly of the VP2(285–293) epitope by immunoproteasomes due to altered cleavage site preferences. The VP2(285–293) peptide was identified to be a high affinity binder, rendering VP2(285–293) a likely candidate for CD8 T cell immunity in CVB3 infection. In conclusion, the concerted usage of different in silico prediction methods and in vitro epitope processing/presentation studies was supportive in the identification of CVB3 MHC-I epitopes.
The ATHENA Framework for Cross-Organizational Business Processes
This chapter contains sections titled: Introduction, E-Procurement Case Study, Related Work, Design of Cross-Organizational Business Processes, Execution of Cross-Organizational Business Processes, Piloting in ATHENA, Conclusion, Acknowledgment, References