Elucidating the Molecular Basis and Regulation of Chromium(VI) Reduction by Shewanella oneidensis MR-1 and Resistance to Metal Toxicity Using Integrated Biochemical, Genomic and Proteomic Approaches

Thompson, Dorothea K. ; Hettich, Robert

Purdue University and Oak Ridge National Laboratory

关键词: Heavy Metals;    Toxicity Chromate Bioremediation, Metal Stress, Shewanella Oneidensis Mr-1, Functional Genomics;    Sediments;    Chromates;    Bioremediation;   

DOI  :  10.2172/898979
RP-ID  :  DE/FE/64163-1 Final Report
RP-ID  :  FG02-06ER64163
RP-ID  :  898979

美国|英语

来源: UNT Digital Library

【 摘 要 】

Shewanella oneidensis MR-1 is a model environmental organism that possesses diverse respiratory capacities, including the ability to reduce soluble Cr(VI) to sparingly soluble, less toxic Cr(III). Chromate is a serious anthropogenic pollutant found in subsurface sediment and groundwater environments due to its widespread use in defense and industrial applications. Effective bioremediation of chromate-contaminated sites requires knowledge of the molecular mechanisms and regulation of heavy metal resistance and biotransformation by dissimilatory metal-reducing bacteria. Towards this goal, our ERSP-funded work was focused on the identification and functional analysis of genes/proteins comprising the response pathways for chromate detoxification and/or reduction. Our work utilized temporal transcriptomic profiling and whole-cell proteomic analyses to characterize the dynamic molecular response of MR-1 to an acute chromate shock (up to 90 min) as well as to a 24-h, low-dose exposure. In addition, we have examined the transcriptome of MR-1 cells actively engaged in chromate reduction. These studies implicated the involvement of a functionally undefined DNA-binding response regulator (SO2426) and a putative azoreductase (SO3585) in the chromate stress response of MR-1.