Collaborative Research: Coupled genetic, geochemical, and physical controls on arsenic mobilization

合作研究：砷迁移的遗传、地球化学和物理耦合控制

• 批准号: 0952019
• 负责人: Scott Fendorf
• 金额: $ 25.86万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0952019&HistoricalAwards=false
• 关键词: Collaborative; Research; Coupled; genetic; geochemical

The hazards imposed by arsenic on human health are well recognized and nowhere better exemplified than South/Southeast Asia where the consumption of arsenic contaminated ground water has resulted high incidences of skin disorders and various cancers. Arsenic is usually associated with iron oxide and other minerals in sediments. However, in the absence of oxygen, microbes can carry out iron and arsenic reduction reactions that result in arsenic release from sediments and accumulation in ground water. The contribution of iron vs. arsenate reduction to arsenic release, however, is unclear. Furthermore, our understanding of arsenic fate and transport within soils and sediments is limited by poorly understood biological and geochemical processes occurring within complex ground water flow pathways. Therefore, the overarching goal of this research is to determine how microbial metabolism impacts arsenic transport in sediments and soils. Specifically, researchers will investigate the expression of bacterial genes responsible for iron and arsenic reduction and commensurate biogeochemical processes responsible for controlling the partitioning and mobility of arsenic (along with their spatial distribution) within model systems that simulate the physical complexity of natural soils and sediments. The proposed research integrates biogeochemical and molecular genetic approaches aimed at developing a mechanistic understanding of the impacts of microbes on arsenic contamination of ground water. Because the nature of the arsenic problem is rooted in geomicrobiology, the intellectual merit of the proposed research is the generation of crucial information important to understanding the mechanism(s) leading to arsenic release or retention in sediments. The results will lead to a detailed conceptual model of how genetics and geochemical processes impact microbe-mineral interactions and arsenic fate. The broader impacts of the research will be to integrate research with teaching activities and community outreach by participating in a laboratory research mentorship program (called ACCESS) for community college students of under represented groups and a high school science summer program called COSMOS. Lastly, the collaboration will enhance and promote diversity through intercampus mentorship of minority graduate students at both Stanford and UCSC.

砷对人类健康施加的危害得到了广泛认可，没有比南亚/东南亚更好地示例的，在那里消费砷污染的地下水导致了皮肤疾病和各种癌症的高发病率。 砷通常与沉积物中的氧化铁和其他矿物质有关。 然而，在没有氧气的情况下，微生物可以进行铁和砷还原反应，从而导致沉积物从沉积物中释放并在地下水中积累。 然而，铁与砷对砷释放的贡献尚不清楚。 此外，我们对土壤和沉积物内砷命运和运输的理解受到复杂地下水流道中发生的生物学和地球化学过程的了解较少。 因此，这项研究的总体目标是确定微生物代谢如何影响沉积物和土壤中的砷运输。 具体而言，研究人员将研究负责铁和砷还原的细菌基因的表达，并在模型系统中控制砷的分配和迁移率（以及它们的空间分布），以模拟自然土壤和道路的物理复杂性。 拟议的研究整合了生物地球化学和分子遗传学方法，旨在发展对微生物对地下水砷污染的影响的机械理解。 由于砷问题的性质植根于地球生物学，因此拟议研究的智力优点是生成至关重要的信息，这对于理解导致沉积物中砷释放或保留的机制很重要。 结果将导致一个详细的概念模型，即遗传学和地球化学过程如何影响微生物的相互作用和砷命运。这项研究的更广泛的影响将是通过参加代表不足的团体的社区大学生和一个名为Cosmos的高中科学夏季计划，将研究与教学活动和社区宣传整合到教学活动和社区外展。 最后，该合作将通过斯坦福大学和UCSC的少数派研究生的竞争界指导来增强和促进多样性。