Collaborative Research: Microbial Mediation of Trace Metal Cycling in Four Stratified Antarctic Lakes

合作研究：南极四个分层湖泊中微量金属循环的微生物介导

• 批准号: 9814837
• 负责人: William Green
• 金额: $ 26.52万
• 依托单位: Miami University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-06-01 至 2003-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9814837&HistoricalAwards=false
• 关键词: Collaborative; Research; Microbial; Mediation; Trace

9814837GREENThe proposed research will examine the role of microbial influences on metal cycling in four stratified lakes in the McMurdo Dry Valleys: Lake Fryxell, Hoare, Joyce and Miers. These lakes are characterized by unusually stable redox transition zones and are especially amenable to a finely spaced sampling regime. Collectively, they represent a broad range of water chemistries. The proposed research will test the following hypotheses: (1) Instratified water columns there will be a clear spatial difference between the onset of manganese reduction and the onset of iron reduction. Heavy metals and rare earth elements will be seen to undergo co-cycling with manganese rather than with iron. (2) In all four lakes, manganese reduction will be associated with the presence of carnobacteria or with other manganese-reducing organisms. In brief, the study will explore the link between microbial activity and the cycling and fate of a large suite of chemical elements at key redox boundaries. Dissolved and particulate metal profiles will be examined as a function of depth from the ice-water interface to the sediments. Profiles will be correlated with microbial manganese-reduction assays and the presence of manganese reducers as detected by screening with Mn-oxide overlay agar plates and nucleic acid hybridizations with probes for known manganese reducers. The research will include significant involvement of undergraduates.

9814837绿色拟议的研究将探讨微生物对金属循环的影响在四个分层湖泊在麦克默多干谷：弗里克塞尔湖，霍尔，乔伊斯和迈尔斯的作用。 这些湖泊的特点是异常稳定的氧化还原过渡区，特别是服从一个细间隔的采样制度。 总的来说，它们代表了广泛的水化学。 本研究将验证以下假设：（1）在不分层的水柱中，锰还原的起始和铁还原的起始之间存在明显的空间差异。 重金属和稀土元素将被视为与锰而不是与铁进行共循环。 (2)在所有四湖中，锰的减少将与肉杆菌或其他锰还原生物的存在有关。 简而言之，该研究将探索微生物活动与关键氧化还原边界处大量化学元素的循环和命运之间的联系。 溶解和颗粒金属剖面将作为从冰水界面到沉积物深度的函数进行检查。 图谱将与微生物锰还原试验和锰还原剂的存在相关，锰还原剂的存在通过锰氧化物覆盖琼脂平板筛选和与已知锰还原剂探针的核酸杂交检测。 这项研究将包括大学生的大量参与。