Geotalea uraniireducens Rf4
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ABSTRACT:
PROVIDER: PRJNA15768 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Differential Gene Expression in G. uraniireducens during Growth on Iron or Manganese Oxide as Electron Acceptor
| PRJNA111053 | ENA
Project description:Analysis of the physiological status of Geobacter uraniireducens growing in uranium-contaminated subsurface sediments
| PRJNA107223 | ENA
Project description:Gene expression patterns under conditions of oxidative stress in Geobacter uraniumreducens
| PRJNA113015 | ENA
Project description:The bacterium Geotalea uraniireducens, commonly found in uranium-contaminated environments, plays a key role in bioremediation strategies by converting the soluble hexavalent form of uranium (U(VI)) into less soluble forms (e.g., U(IV)). While most of the reduction and concomitant precipitation of uranium occur outside the cells, there have been reports of important reduction processes taking place in the periplasm. In any case, the triheme periplasmic cytochromes are key players, either by ensuring an effective interface between the cell's interior and exterior or by directly participating in the reduction of the metal. Therefore, understanding the functional mechanism of the highly abundant triheme cytochromes in G. uraniireducens' is crucial for elucidating the respiratory pathways in this bacterium. In this work, a detailed functional characterization of the triheme cytochromes PpcA and PpcB from G. uraniireducens was conducted using NMR and visible spectroscopy techniques. Despite sharing high amino acid sequence identity and structural homology with their counterparts from Geobacter sulfurreducens, the results showed that the heme reduction potential values are less negative, the order of oxidation of the hemes is distinct, and the redox and redox-Bohr network of interactions revealed unprecedented functional mechanisms in the cytochromes of G. uraniireducens. In these cytochromes, the reduction potential values of the three heme groups are much more similar, resulting in a narrower range of values, that facilitates directional electron flow from the inner membrane, thereby optimizing the uranium reduction.
| S-EPMC11787507 | biostudies-literature
Project description:Desulfotomaculum reducens is the first Gram-positive sulfate- and metal- reducing bacterium for which the transcriptomic response to uranium exposure has been evaluated. The genes upregulated during fermentative growth in the presence of U(VI) as compared to its absence included those encoding for proteins involved in respiration such as NADH quinone oxidoreductase and heterodisulfide reductase. This finding suggested that electrons were shuttled to the electron transport chain during fermentation which points to the reduction of U(VI) as a metabolic process. While U(IV) is typically insoluble and readily removable by filtration, U(IV) produced during active growth was not retained by a 0.2 µm pore size filter and filtration was not sufficient to differentiate between U(VI) and U(IV). In addition, genes involved in iron homeostasis were upregulated in the presence of uranium, which was consistent with the upregulation of genes involved in c-type cytochrome biogenesis. Despite the upregulation of cytochrome biosynthesis genes, the sole c-type cytochrome encoded in the genome was not differentially expressed. Finally, genes encoding metal efflux pumps were also upregulated indicating the toxic nature of uranium. Analysis of the time-dependent gene expression showed that sporulation was the dominant process at the early stationary phase and that the presence of U at that stage did not impact expression. This data set is a time course comparing sulfate and uranium reduction with fermentative growth.
2010-07-15 | E-GEOD-22944 | biostudies-arrayexpress
Project description:Geobacteraceae transfer electrons from a donor such as acetate to an electron acceptor such as Fe(III) or U(VI). Geobacter uraniireducens is found in uranium-contaminated sites and plays an important role in in situ bioremediation. In this experiment, gene expression was compared between G. uraniireducens cultures grown in sediments from a uranium contaminated site amended with acetate and cultures grown in acetate/fumarate medium. Keywords: two-condition comparison
2008-10-20 | GSE10920 | GEO