Project description:This SuperSeries is composed of the following subset Series: GSE8015: Pyruvate fermentation vs Lactate-Sulfate GSE8037: Hydrogen vs Lactate as electron donor in Sulfate reduction GSE8071: Pyruvate vs Lactate as electron donor in Sulfate reduction GSE8072: Thiosulfate vs Sulfate as electron acceptor in Sulfate reduction Keywords: SuperSeries Refer to individual Series
Project description:The sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough possesses four periplasmic hydrogenases to facilitate the oxidation of molecular hydrogen. These include an [Fe], a [NiFeSe] and two [NiFe] hydrogenases encoded by the hyd, hys, hyn1 and hyn2 genes, respectively. In order to understand their cellular functions the expression levels of these hydrogenases, along with the growth rate analysis of mutant strains, was determined during growth on defined media under 3 different conditions. These conditions incuded lactate or hydrogen at either 5% or 50% (vol/vol) used as the sole electron donor for sulfate reduction. Keywords: Electron donor change
Project description:The sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough possesses four periplasmic hydrogenases to facilitate the oxidation of molecular hydrogen. These include an [Fe], a [NiFeSe] and two [NiFe] hydrogenases encoded by the hyd, hys, hyn1 and hyn2 genes, respectively. In order to understand their cellular functions the expression levels of these hydrogenases, along with the growth rate analysis of mutant strains, was determined during growth on defined media under 3 different conditions. These conditions incuded lactate or hydrogen at either 5% or 50% (vol/vol) used as the sole electron donor for sulfate reduction. Keywords: Electron donor change For each condition 2 unique biological samples were hybridized to 4 arrays that each contained duplicate spots. Genomic DNA was used as universal reference. After total intensity normalization the SAM (significance analysis of microarrays) was used to find differentially expressed genes.
Project description:In order to obtain a global view of energy metabolism pathways of the sulfate-reducer Desulfovibrio vulgaris Hildenborough and the proteins involved therein whole-genome microarrays were used to compare the transcriptional response of cells grown with hydrogen/sulfate, pyruvate/sulfate, lactate/thiosulfate, and pyruvate with limiting sulfate, relative to growth in standard lactate/sulfate condition. Growth with hydrogen/sulfate showed the largest number of differently expressed genes and the largest changes in expression levels. The most up-regulated energy metabolism genes were those coding for the periplasmic [NiFeSe] hydrogenase, followed by the Ech hydrogenase, and the most down-regulated were genes coding for the Coo hydrogenase. The results point to the involvement of formate cycling and the ethanol pathway during growth on hydrogen, whereas there is evidence for CO cycling during growth on lactate and pyruvate, but not on H2. Growth with thiosulfate showed the hallmarks of a reduced energy status of the cells with down regulation of the ATP synthase and the Qmo and Dsr complexes., whereas growth with pyruvate showed the smallest differences but an increased role for the Ech hydrogenase.that in this case functions in reverse from the case of growth with H2. The multiple periplasmic hydrogenases and formate dehydrogenases, do not display the same regulation pattern showing that their metabolic roles are not totally interchangeable. This result together with the observation that several genes coding for proteins that have not been biochemically characterised were considerably affected in this study, reveals a more complex energy metabolism than previously considered and provides guidance for further studies. Keywords: Growth protocol Desulfovibrio vulgaris from our laboratory culture collection was cultured at 37°C with hydrogen as the only electron donor (with sulfate as the electron acceptor) to mid-log phase. Cultures were also cultivated similarly using lactate as the sole electron donor to mid-log phase. Gene expression profiles of cultures grown with hydrogen as the electron donor were compared with those of the cultures grown with lactate as the electron donor for sulfate reduction. Total RNA was harvested from four replicate cultures for microarray analysis. RNA extraction, purification, and labeling were performed independently on each cell sample.Two samples of each total RNA preparation were labeled, one with Cy3-dUTP and another with Cy5-dUTP for microarray hybridization (dye swap).
Project description:In order to obtain a global view of energy metabolism pathways of the sulfate-reducer Desulfovibrio vulgaris Hildenborough and the proteins involved therein whole-genome microarrays were used to compare the transcriptional response of cells grown with hydrogen/sulfate, pyruvate/sulfate, lactate/thiosulfate, and pyruvate with limiting sulfate, relative to growth in standard lactate/sulfate condition. Growth with hydrogen/sulfate showed the largest number of differently expressed genes and the largest changes in expression levels. The most up-regulated energy metabolism genes were those coding for the periplasmic [NiFeSe] hydrogenase, followed by the Ech hydrogenase, and the most down-regulated were genes coding for the Coo hydrogenase. The results point to the involvement of formate cycling and the ethanol pathway during growth on hydrogen, whereas there is evidence for CO cycling during growth on lactate and pyruvate, but not on H2. Growth with thiosulfate showed the hallmarks of a reduced energy status of the cells with down regulation of the ATP synthase and the Qmo and Dsr complexes., whereas growth with pyruvate showed the smallest differences but an increased role for the Ech hydrogenase.that in this case functions in reverse from the case of growth with H2. The multiple periplasmic hydrogenases and formate dehydrogenases, do not display the same regulation pattern showing that their metabolic roles are not totally interchangeable. This result together with the observation that several genes coding for proteins that have not been biochemically characterised were considerably affected in this study, reveals a more complex energy metabolism than previously considered and provides guidance for further studies. Keywords: Growth protocol Desulfovibrio vulgaris Hildenborough was cultured at 37°C with pyruvate as the only electron donor (with sulfate as the electron acceptor) to mid-log phase. Cultures were also cultivated similarly using lactate as the sole electron donor to mid-log phase. Gene expression profiles of cultures grown with pyruvate as the electron donor were compared with those of the cultures grown with lactate as the electron donor for sulfate reduction. Total RNA was harvested from three replicate cultures for microarray analysis. RNA extraction, purification, and labeling were performed independently on each cell sample.Two samples of each total RNA preparation were labeled, one with Cy3-dUTP and another with Cy5-dUTP for microarray hybridization (dye swap).
Project description:The gene expression profile of wild-type Desulfovibrio vulgaris grown on cathodic hydrogen, generated at an iron electrode surface with an imposed negative potential of -1.1 V (cathodic protection conditions). The gene expression profile of cells grown on cathodic hydrogen was compared to that of cells grown with gaseous hydrogen bubbling through the culture. Relative to the latter, the electrode-grown cells over-expressed two hydrogenases, the hyn1 genes for [NiFe] hydrogenase-1, and the hyd genes, encoding [Fe] hydrogenase. The hmc genes for the high molecular weight cytochrome (Hmc) complex, which allows electron flow from the hydrogenases across the cytoplasmic membrane, were also over-expressed. In contrast, cells grown on gaseous hydrogen over-expressed the hys genes for [NiFeSe] hydrogenase. Cells growing on the electrode also over-expressed genes encoding proteins which promote biofilm formation. Although the gene expression profiles for these two modes of growth were distinct, they were more closely related to each other than to that for cells grown in a lactate- and sulfate-containing medium. Electrochemically measured corrosion rates were lower for iron electrodes covered with hyn1-, hyd-, and hmc-mutant biofilms, as compared to wild-type biofilms. This confirms the importance, suggested by the gene expression studies, of the corresponding gene products in D. vulgaris-mediated iron corrosion. Keywords: Growth on Iron Electrode and Biofilm formation