PECASE: Mercury Methylation in Sulfate-Reducing Biofilms

PECASE：硫酸盐还原生物膜中的汞甲基化

• 批准号: 0348783
• 负责人: Jennifer Jay
• 金额: $ 40.01万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-15 至 2009-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0348783&HistoricalAwards=false
• 关键词: PECASE; Mercury; Methylation; Sulfate; Reducing

0348783JayMercury (Hg) contamination of food chains is a worldwide problem, posing public health threats even in pristine areas. In aquatic systems, mercury methylation is a key process, whereby less-toxic inorganic mercury is microbially transformed to methylmercury, which is a potent neurotoxin with a strong tendency to magnify in concentration in food chains. While the process of mercury methylation is critical to understand if we are to predict or mitigate impacts due to mercury contamination, the factors controlling its rate are extremely complex. Sulfate-reducing bacteria (SRB) have been shown to be the primary mercury methylators in a wide range of aquatic systems, and bioavailability of mercury to the bacteria, as well as the activity of particular species of sulfate-reducing bacteria present, have both been shown to be important factors in controlling the rate of mercury methylation. Intellectual merit: This work addresses fundamental questions regarding the environmental factors controlling mercury methylation. This work will elucidate the effects of mercury speciation on methylation in reducing environments, the importance of the strain of sulfate-reducing bacteria, and the effects of biofilm formation on methylation in sulfate-reducing biofilms. Results from the educational innovations in service-learning will also be made available to the public via the literature and web-accessible documents. Broader impacts: Results from the proposed work are necessary for accurately modeling of the fate of mercury in the environment. Information gained can be extended to the study of other contaminants in biofilm systems, both natural and engineered. This work may also be directly applicable to wetland restoration and lake management decisions. The PI is currently working with the UCLA Center for Experiential Education and Service Learning (CEESL) to develop an innovative service-learning course in which UCLA students will learn and then teach wetland functions in grade 6 classrooms to economically disadvantaged students of Los Angeles. The teaching unit to be developed will involve four in-class laboratory sessions and will culminate in a field trip for the grade 6 students (accompanied by the UCLA students) to Ballona Wetland. A teacher training to support the wetland science curriculum will be given by the PI each summer.

0348783 JayMercury（Hg）污染食物链是一个世界性的问题，即使在原始地区也会对公众健康构成威胁。 在水生系统中，汞甲基化是一个关键过程，毒性较低的无机汞通过微生物转化为甲基汞，甲基汞是一种强效神经毒素，在食物链中的浓度有放大的强烈趋势。 虽然汞甲基化过程对于了解我们是否要预测或减轻汞污染的影响至关重要，但控制其速率的因素极其复杂。 硫酸盐还原菌（SRB）已被证明是广泛的水生系统中的主要汞甲基化剂，汞对细菌的生物利用度以及存在的特定硫酸盐还原菌物种的活性都被证明是控制汞甲基化速率的重要因素。智力价值：这项工作解决了有关控制汞甲基化的环境因素的基本问题。 这项工作将阐明汞形态对甲基化在还原环境中的影响，硫酸盐还原菌菌株的重要性，以及硫酸盐还原生物膜中甲基化的生物膜形成的影响。 服务学习的教育创新成果也将通过文献和网络文件向公众提供。更广泛的影响：拟议工作的结果对于准确模拟汞在环境中的归宿是必要的。 所获得的信息可以扩展到生物膜系统中的其他污染物的研究，包括天然的和工程的。 这项工作也可能直接适用于湿地恢复和湖泊管理决策。 PI目前正在与加州大学洛杉矶分校体验教育和服务学习中心（CEESL）合作，开发一个创新的服务学习课程，加州大学洛杉矶分校的学生将学习，然后在6年级的教室里向洛杉矶经济困难的学生教授湿地功能。 要开发的教学单元将包括四个课堂实验室课程，并将在6年级学生（由加州大学洛杉矶分校的学生陪同）到Ballona湿地的实地考察中达到高潮。 每年夏天，PI将提供教师培训，以支持湿地科学课程。