title: Metabolic response of Agrobacterium tumefaciens 5A to arsenite.
abstract: Wide-spread abundance in soil and water, coupled with high toxicity have put arsenic at the top of the list of environmental contaminants. Early studies demonstrated that both concentration and the valence state of inorganic arsenic (arsenite, As(III) vs. arsenate As(V)) can be modulated by microbes. Using genetics, transcriptomic and proteomic techniques, microbe-arsenic detoxification, respiratory As(V) reduction and As(III) oxidation have since been examined. The effect of arsenic exposure on whole-cell intracellular microbial metabolism, however, has not been extensively studied. We combined LC-MS and1H NMR to quantify metabolic changes in Agrobacterium tumefaciens (strain 5A) upon exposure to sub-lethal concentrations of As(III). Metabolomics analysis reveals global differences in metabolite concentrations between control and As(III) exposure groups, with significant perturbations to intermediates shuttling into and cycling within the TCA cycle. These data are most consistent with the disruption of two key TCA cycle enzymes, pyruvate dehydrogenase and α-ketoglutarate dehydrogenase. Glycolysis also appeared altered following As(III) stress, with carbon accumulating as complex saccharides. These observations suggest that an important consequence of As(III) contamination in nature will be to alter microbial carbon metabolism at the microbial community level and thus has the potential to foundationally impact all biogeochemical cycles in the environment.
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, 59717, USA.
authors.forename: Monika
authors.initials: M
authors.lastname: Tokmina-Lukaszewska
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, 59717, USA.|State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
authors.forename: Zunji
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, 59717, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Tripet
authors.affiliation: Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, 59717, USA.
authors.forename: Timothy R
authors.initials: TR
authors.lastname: McDermott
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, 59717, USA.
authors.forename: Valérie
authors.initials: V
authors.lastname: Copié
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, 59717, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Bothner
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
authors.forename: Gejiao
authors.initials: G
authors.lastname: Wang
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000378:metabolism*; D018053:Arsenites / Q000378:metabolism*; D010084:Oxidation-Reduction; D040901:Proteomics; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D018053:Arsenites; D012989:Soil Pollutants; C015001:arsenite