Metabolic response of Agrobacterium tumefaciens 5A to arsenite: Altered regulation of metabolic pathways by arsenite
Metabolic response of Agrobacterium tumefaciens 5A to arsenite: Altered regulation of metabolic pathways by arsenite
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根癌农杆菌 5A 对亚砷酸盐的代谢反应：亚砷酸盐改变代谢途径的调节
DOI：
10.1111/1462-2920.13615
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发表时间：
2017
影响因子：
5.1
通讯作者：
Wang, Gejiao
中科院分区：
文献类型：
--
作者：
Tokmina-Lukaszewska, Monika;Shi, Zunji;Tripet, Brian;McDermott, Timothy R.;Copié, Valérie;Bothner, Brian;Wang, Gejiao
砷在土壤和水中的广泛存在以及高毒性使砷成为环境污染物中的首位。早期研究表明，微生物可以调节无机砷（亚砷酸盐、As(III) 与砷酸盐 As(V)）的浓度和价态。此后，人们利用遗传学、转录组学和蛋白质组学技术，对微生物砷解毒、呼吸 As(V) 还原和 As(III) 氧化进行了研究。然而，砷暴露对全细胞胞内微生物代谢的影响尚未得到广泛研究。我们结合 LC-MS 和 1 H NMR 来量化根癌农杆菌（菌株 5A）在暴露于亚致死浓度的 As(III) 后的代谢变化。代谢组学分析揭示了对照组和 As(III) 暴露组之间代谢物浓度的整体差异，对穿梭于 TCA 循环并在其内循环的中间体存在显着干扰。这些数据与丙酮酸脱氢酶和 α-酮戊二酸脱氢酶这两种关键 TCA 循环酶的破坏最为一致。 As(III) 胁迫后糖酵解也出现改变，碳以复合糖的形式积累。这些观察结果表明，自然界中 As(III) 污染的一个重要后果将是改变微生物群落水平的微生物碳代谢，因此有可能从根本上影响环境中的所有生物地球化学循环。
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 inAgrobacterium 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.