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
Project description:Previous analysis of gene transcript levels of Geobacter species in groundwater during in situ bioremediation of a uranium-contaminated aquifer detected expression of genes encoding superoxide dismutase (sodA) and cytochrome d ubiquinol oxidase (cydA), proteins known to be involved in the response to oxidative stress in other microorganisms. In order to further elucidate gene expression patterns that could be attributed to oxygen exposure, G. uraniumreducens was grown with acetate as the electron donor and fumarate as the electron acceptor in the presence of oxygen and compared to non-oxygen treated cultures.
Project description:Cyanobacteria inhabit dynamic redox environments influenced by diurnal cycles, environmental fluctuations, and nutrient availability, necessitating tight redox regulation. This RNA-seq study examines transcriptional regulation of redox control in the model cyanobacterium Synechococcus elongatus PCC 7942 under controlled turbidostatic conditions. We manipulated oxygen concentrations to generate oxidative stress across distinct phases, measuring impacts on growth, physiology, and genome-wide gene expression. Transcriptional profiling reveals independently regulated gene modules that define graded transcriptional responses aligned with redox-regulated patterns activated under fluctuating light conditions. Our findings demonstrate a coordinated, multi-phase response involving ROS formation, detoxification, and damage repair. Oxidative stress induces transcriptional repression of essential cellular processes. This dataset includes wild-type strains under acute oxidative stress and experimentally evolved populations that underwent multiple rounds of elevated oxygen exposure. The evolved strains demonstrated improved tolerance to elevated oxygen levels, enhanced sucrose productivity under high-stress conditions, and accumulated DNA mutations in genes related to molybdopterin biosynthesis and glycogen metabolism.
Project description:This SuperSeries is composed of the following subset Series: GSE22497: Transcriptome analysis of Geobacter sulfurreducens under multiple growth conditions GSE22503: ChIP-chip of Geobacter sulfurreducens PCA with antibody against RNAP and RpoD under various conditions GSE22511: Genome-wide transcription start site determination of Geobacter sulfurreducens under multiple growth conditions Refer to individual Series
