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dc.contributor.authorHocking, William Petereng
dc.contributor.authorStokke, Runareng
dc.contributor.authorRoalkvam, Ireneeng
dc.contributor.authorSteen, Ida Heleneeng
dc.PublishedFrontiers in Microbiology 2014, 5:95eng
dc.description.abstractEnergy conservation via the pathway of dissimilatory sulfate reduction is present in a diverse group of prokaryotes, but is most comprehensively studied in Deltaproteobacteria. In this study, whole-genome microarray analyses were used to provide a model of the energy metabolism of the sulfate-reducing archaeon Archaeoglobus fulgidus, based on comparative analysis of litoautotrophic growth with H2/CO2 and thiosulfate, and heterotrophic growth on lactate with sulfate or thiosulfate. Only 72 genes were expressed differentially between the cultures utilizing sulfate or thiosulfate, whereas 269 genes were affected by a shift in energy source. We identified co-located gene cluster encoding putative lactate dehydrogenases (LDHs; lldD, dld, lldEFG), also present in sulfate-reducing bacteria. These enzymes may take part in energy conservation in A. fulgidus by specifically linking lactate oxidation with APS reduction via the Qmo complex. High transcriptional levels of Fqo confirm an important role of F420H2, as well as a menaquinone-mediated electron transport chain, during heterotrophic growth. A putative periplasmic thiosulfate reductase was identified by specific up-regulation. Also, putative genes for transport of sulfate and sulfite are discussed. We present a model for hydrogen metabolism, based on the probable bifurcation reaction of the Mvh:Hdl hydrogenase, which may inhibit the utilization of Fdred for energy conservation. Energy conservation is probably facilitated via menaquinone to multiple membrane-bound heterodisulfide reductase (Hdr) complexes and the DsrC protein—linking periplasmic hydrogenase (Vht) to the cytoplasmic reduction of sulfite. The ambiguous roles of genes corresponding to fatty acid metabolism induced during growth with H2 are discussed. Putative co-assimilation of organic acids is favored over a homologous secondary carbon fixation pathway, although both mechanisms may contribute to conserve the amount of Fdred needed during autotrophic growth with H2.en_US
dc.rightsAttribution CC BYeng
dc.subjectArchaeoglobus fulgiduseng
dc.subjectheterodisulfide reductaseeng
dc.subjectdissimilatory sulfate reductioneng
dc.subjectlactate dehydrogenaseeng
dc.titleIdentification of key components in the energy metabolism of Archaeoglobus fulgidus by transcriptome analysesen_US
dc.typePeer reviewed
dc.typeJournal article
dc.rights.holderCopyright 2014 The Authorsen_US
dc.relation.projectNorges forskningsråd: 179560
dc.subject.nsiVDP::Matematikk og naturvitenskap: 400::Basale biofag: 470::Generell mikrobiologi: 472
dc.subject.nsiVDP::Mathematics and natural scienses: 400::Basic biosciences: 470::General microbiology: 472

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