Role of Thioarsenic Compounds in As(III) Oxidation in an Alkaline Lake

硫代砷化合物在碱性湖中 As(III) 氧化中的作用

• 批准号: 0952271
• 负责人: James Hollibaugh
• 金额: $ 42.3万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0952271&HistoricalAwards=false
• 关键词: Role; Thioarsenic; Compounds; III; Oxidation

This research will seek to elucidate the pathway for thioarsenate decomposition by microbial assemblages, using alkaline, sulfidic and arsenic-enriched Mono Lake bottom waters as a study site. Enrichment cultures and manipulation experiments will be performed to test the effects of different electron acceptors on thioarsenate decomposition. The PI will analyze the microbial communities to determine which organisms and which enzyme systems respond to enrichments with thioarsenates to aid in identifying pathways. These experiments are designed to address the following questions: 1) What is the behavior of thioarsenate with arsenate, nitrate or oxygen as electron acceptors? Are there specific groups of microbes associated with each pair of reactants? 2) What are the products of the reaction? 3) How does gene expression change during thioarsenate decomposition? What are the pathways involved in thioarsenate oxidation? The results of this study will be relevant, not only for a better understanding arsenic cycling in Mono Lake, but for modeling arsenic in other neutral or alkaline environments where arsenite and sulfide are present and exposed to changing redox conditions. Thioarsenate transformation may be of particular importance in alkaline hot springs, industrial waste sites, or aquifers with bedrock containing arsenic- and sulfur-bearing minerals. One outcome will be a better understanding of arsenic transformations and mobility under fluctuating redox conditions in anoxic groundwater. The information may also be useful in designing bioremediation strategies. The proposed studies are also relevant to understanding and modeling the role of arsenic in the early stages of the evolution of life on Earth.

本研究将试图阐明硫代砷酸盐分解的微生物组合的途径，使用碱性，硫化物和砷富集的莫诺湖底部沃茨作为研究地点。将进行富集培养和操作实验，以测试不同电子受体对硫代砷酸盐分解的影响。PI将分析微生物群落，以确定哪些微生物和哪些酶系统对硫代砷酸盐富集反应，以帮助识别途径。这些实验旨在解决以下问题：1）硫代砷酸盐与砷酸盐、硝酸盐或氧作为电子受体的行为如何？每一对反应物都有特定的微生物群吗？2)反应的产物是什么？3)硫代砷酸盐分解过程中基因表达如何变化？硫代砷酸盐氧化的途径是什么？这项研究的结果将是相关的，不仅为更好地了解砷循环在莫诺湖，但砷在其他中性或碱性环境中，亚砷酸盐和硫化物的存在和暴露于不断变化的氧化还原条件建模。硫代砷酸盐转化在碱性温泉、工业废料场或含有含砷和含硫矿物的基岩含水层中可能特别重要。结果之一将是更好地了解砷的转化和流动性波动的氧化还原条件下缺氧地下水。这些信息也可能有助于设计生物修复策略。拟议的研究也与理解和模拟砷在地球生命进化早期阶段的作用有关。