Inhibition of methanogenesis leads to accumulation of methylated arsenic species and enhances arsenic volatilization from rice paddy soil
Inhibition of methanogenesis leads to accumulation of methylated arsenic species and enhances arsenic volatilization from rice paddy soil
复制标题
抑制产甲烷作用导致甲基化砷形态的积累并增强稻田土壤中砷的挥发
DOI：
10.1016/j.scitotenv.2021.151696
复制
发表时间：
2022
影响因子：
9.8
通讯作者：
Reid, Matthew C.
中科院分区：
文献类型：
--
作者：
Zhang, Xuhui;Reid, Matthew C.
淹水土壤是砷（As）生物甲基化和随后挥发的重要环境，砷是全球关注的污染物。无机物质转化为甲基化的氧化砷物质被认为是挥发性（甲基）胂的生产和排放的限速步骤。虽然产甲烷菌和硫酸盐还原菌（SRB）已被确定为厌氧土壤中甲基化砷氧化物浓度的重要调节剂，这些微生物群体对生物挥发的影响仍不清楚。在这里，与阿肯色州，美国，水稻土的微宇宙和批量培养实验进行了代谢抑制，以测试产甲烷活性的影响As形态和生物挥发。抑制甲烷与2-溴乙烷磺酸盐（BES）导致甲基化的氧砷物种的积累，主要是二甲基胂酸（DMAs（V）），和四倍增加作为生物挥发相比，控制土壤。我们的结果支持了一个概念模型，即产甲烷活动通过提高As脱甲基化率来抑制生物挥发。这项工作完善的认识，调节生物挥发在厌氧土壤环境中的地球化学过程，并扩展最近的见解甲烷和代谢之间的联系，从美国中南部水稻生产区的土壤。
Flooded soils are important environments for the biomethylation and subsequent volatilization of arsenic (As), a contaminant of global concern. Conversion of inorganic to methylated oxyarsenic species is thought to be the rate-limiting step in the production and emission of volatile (methyl)arsines. While methanogens and sulfate-reducing bacteria (SRB) have been identified as important regulators of methylated oxyarsenic concentrations in anaerobic soils, the effects of these microbial groups on biovolatilization remain unclear. Here, microcosm and batch incubation experiments with an Arkansas, USA, rice paddy soil were performed in conjunction with metabolic inhibition to test the effects of methanogenic activity on As speciation and biovolatilization. Inhibition of methanogenesis with 2-bromoethanesulfonate (BES) led to the accumulation of methylated oxyarsenic species, primarily dimethylarsinic acid (DMAs(V)), and a four-fold increase in As biovolatilization compared to a control soil. Our results support a conceptual model that methanogenic activity suppresses biovolatilization by enhancing As demethylation rates. This work refines understanding of biogeochemical processes regulating As biovolatilization in anaerobic soil environments, and extends recent insights into links between methanogenesis and As metabolism to soils from the mid-South United States rice production region.