Biogeochemical Cycling of Heavy Metals in Lake Coeur d'Alene Sediments: The Role of Indigenous Microbial Communities

科达伦湖沉积物中重金属的生物地球化学循环：本土微生物群落的作用

• 批准号: 0628258
• 负责人: Brent Peyton
• 金额: --
• 依托单位: Montana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0628258&HistoricalAwards=false
• 关键词: Biogeochemical; Cycling; Heavy; Metals; Lake

0420374PeytonHeavy metals are highly toxic in the environment and their presence in sediments of Lake Coeur d'Alene (LCdA) in Idaho is mainly the result of historical mining in the mountains upstream. The objectives of this project are to 1) characterize the diversity of microorganisms in LCdA sediments using modern molecular biology techniques, 2) quantify the role of individual members of the microbial community in biogeochemical cycling of metals (Cu, Pb, and Zn), and 3) develop a dynamic numeric biogeochemical model of heavy metal cycling in sediment systems, calibrated to the unique environments of LCdA. These objectives will be met while testing the following overall hypothesis:A complex and dynamic community of phylogenetically distinct and previously uncharacterized microorganisms is present in the historically metal-contaminated sediments of Lake Coeur d'Alene. In response to a toxic metal stress, metal-tolerant species will dominate metal-sensitive species present in the sediments, with temporal and spatial microbial distribution and diversity dependant on the metal type and concentration. Dynamic biogeochemical models that incorporate chemical transport and reaction with novel microbial stress/response relationships and community dynamics can be used to 1) integrate complex microbial and geochemical observations across spatial and temporal scales, and 2) better predict broad community level response and influence on toxic metal cycling.Intellectual merit of the proposed activity: This project will significantly improve the quantitative understanding of interaction and response of a sediment microbial community subjected to severe heavy metal stress. Project objectives will be achieved by sampling LCdA sediments and identifying microbial diversity based on both 16S rDNA and rpoB gene sequences. These molecular techniques greatly facilitate the study of microbes in their natural environments and will provide a rational platform to base observations of community response to toxic metal additions. Shifts in microbial populations after being subjected to metal-stress will be quantified using terminal-restriction fragment length polymorphism (T-RFLP). Focused laboratory studies will be used to quantify the effects of toxic metals on microbial growth and inhibition for incorporation into the predictive model. The modeling effort will integrate for the first time to our knowledge, syntrophic consortium biotransformation dynamics, dose-dependent inhibition, and spatial and temporal dynamics of redox front formation under a diffusive transport regime. Broader impacts resulting from the proposed activity: While the research is focused on microbial communities in historically metal contaminated LCdA sediment, with increased industrialization worldwide, interactions of the environment and human contaminants have become more important issues, scientifically and socially, to the U.S. and internationally. The project integrates research mentoring and training of graduates, postdoctoral associate, and a research faculty. A supplemental grant for research experiences for undergraduates will be used to integrate undergraduate students into the research. The results will be published in a number of quality peer reviewed journal articles and will be conveyed to the public through presentations at local regulatory and public meetings, and at national and international conferences. An internet web site written for both scientists and non-technical readers will be developed. When complete, this research will significantly expand the fundamental and quantitative understanding of key biogeochemical processes for metals. The project has the potential to suggest fundamental improvements in metals-bioremediation technologies, since results will be broadly applicable in supporting innovative biological strategies to reduce human health risks and environmental damage from metal contaminated sites

0420374PeytonHeavy金属在环境中具有剧毒，并且它们在爱达荷州Coeur d'Alene湖（LCDA）的沉积物中的存在主要是上游山区历史采矿的结果。 该项目的目标是1）表征使用现代分子生物学技术在LCDA沉积物中的多样性，2）量化微生物群落中各个成员在金属的生物地球化学循环中的作用lcda。 在测试以下总体假设时，将实现这些目标：在历史悠久的Coeur d'Alene湖的历史悠久的金属污染沉积物中，存在于系统发育差异和以前未表征的微生物的复杂而动态的社区。 为了响应有毒的金属应激，金属耐受的物种将主导沉积物中存在的金属敏感物种，其时间和空间微生物分布以及多样性取决于金属类型和浓度。 动态生物地球化学模型将化学传输和反应与新型的微生物应力/反应关系和社区动力学结合到1）整合了跨空间和时间尺度的复杂的微生物和地球化学观测，以及2）更好地预测社区水平的响应，并预测广泛的社区对毒性金属的影响。重金属应力。 通过对LCDA沉积物进行采样并根据16S rDNA和RPOB基因序列鉴定微生物多样性来实现项目目标。 这些分子技术极大地促进了微生物在自然环境中的研究，并将为社区对有毒金属添加的反应提供理性的平台。 受到金属压力后，微生物种群的变化将使用末端限制片段长度多态性（T-RFLP）进行定量。 专注的实验室研究将用于量化有毒金属对微生物生长的影响，并抑制纳入预测模型。建模工作将首次综合我们所知，在扩散运输方向下，氧化还原依赖性抑制和氧化还原前部形成的空间和时间动力学。 拟议活动引起的更广泛的影响：尽管该研究集中在历史上金属污染的LCDA沉积物中的微生物群落上，但全球工业化的增加，但环境和人类污染物的相互作用在科学和社会上已成为美国和国际化的问题。 该项目集成了研究和培训毕业生，博士后助理和研究教师的培训。 针对本科生的研究经验的补充赠款将用于将本科生纳入研究。 结果将在许多优质的同行评审期刊文章中发表，并将通过当地监管和公共会议以及国家和国际会议的演讲传达给公众。 将开发为科学家和非技术读者编写的互联网网站。 完成后，这项研究将大大扩展对金属生物地球化学过程的基本和定量理解。 该项目有可能提出金属 - 修复技术的基本改进，因为结果将广泛用于支持创新的生物学策略，以降低人类健康风险和金属污染地点的环境损害