Collaborative Research: Anammox in a shallow coastal aquifer - combining in situ stable isotope and molecular approaches to examine controls on rates and communities

智力优势：地下水拥有大量的DIN（溶解无机氮）储备，停留时间较长。目前的分析表明，全球20%的DIN转化为N2（通过反硝化作用）发生在含水层中。PI将专注于新发现的DIN反应途径，厌氧氨氧化（anammox），将NH 4+与NO2-结合产生N2。虽然厌氧氨氧化已被证明是DIN损失在许多海洋系统中的一个重要途径，它几乎是完全没有特点的地下水环境，尽管地球化学条件，应促进其活动。初步证据表明，厌氧氨氧化可能超过反硝化作用在富氮含水层。PI建议通过一系列实验室和新开发的原位分子和同位素调查，在地球化学和微生物水平上调查厌氧氨氧化及其与反硝化和硝化的联系。本研究的总体目标是解决以下问题：1）厌氧氨氧化是否发生在足够的原位速率，以保证其考虑作为一个重要的机制，在地下水运输过程中的N损失？2)地下水中是否有指示性的厌氧氨氧化物化学或同位素特征，可以帮助其检测和定量？拟议的工作将产生第一次报告的地下水原位厌氧氨氧化率，并定义微生物氮循环群落（厌氧氨氧化，反硝化，硝化）如何相互作用的互利或竞争的方式来调节含水层中的氮的命运。更广泛的影响：该项目通过康州大学环境科学与工程中心（CESE）提供实习机会。向UNCW和UCONN提供研究生支助。托拜厄斯作为康涅狄格大学海岸研究本科专业的协调员，处于独特的地位，将这项工作纳入本科教育。该项目利用UNCW中心的本科生研究和奖学金，并将帮助支持两个部门的荣誉学位。高中生的研究经验将在UNCW“夏季海洋冒险”计划中获得，参与者将帮助进行DNA分析，研究生将担任导师。该项目将支持一个关于将地下水DIN污染与沿海富营养化联系起来的公开讲座，作为康州大学“沿海展望”和UNCW“行星海洋”公开讲座系列的一部分。成功的努力，以增加地下水厌氧氨氧化可能会导致修复建议，可以通过马萨诸塞州美国地质调查局地区办事处转移到区域经理。

Intellectual merit: Groundwater holds a large reserve of DIN (dissolved inorganic nitrogen) with extended residence times. Current analysis suggests that 20% of global DIN conversion to N2 (via denitrification) occurs in aquifers. The PIs will focus their efforts on a newly discovered DIN reaction pathway, anaerobic ammonium oxidation (anammox) that combines NH4+ with NO2- to produce N2. Although anammox has proven to be an important route of DIN loss in many marine systems, it is almost completely uncharacterized in groundwater environments despite geochemical conditions that should promote its activity. The preliminary evidence suggests that anammox may exceed denitrification in N-rich aquifers. The PIs propose to investigate anammox, and its connection(s) to denitrification and nitrification at the geochemical and microbial levels through a series of laboratory and newly developed in situ molecular and isotopic investigations. The overall goal of this study is to address the following questions: 1) Does anammox occur at sufficient in situ rates to warrant its consideration as an important mechanism of N loss during groundwater transport? 2) Are there indicative chemical or isotopic signatures for anammox in groundwater that can aid in its detection and quantification? The proposed work will yield the first reported in situ anammox rates for groundwater and define how microbial nitrogen cycling communities (anammox, denitrification, nitrification) interact in a mutualistic or competitive fashion to regulate nitrogen fate in aquifers. Broader impacts: The project provides internship opportunities through the UCONN Center for Environmental Science and Engineering (CESE). Graduate student support is provided to UNCW and UCONN. Tobias is in a unique position as Coordinator for the UCONN Coastal Studies undergraduate major to incorporate this work into undergraduate education. The project leverages the UNCW Center for Undergraduate Research and Fellowship and will help support two departmental honors degrees. Research experience for high school students will be achieved within the UNCW "Summer Ocean Ventures" program where participants will help with DNA analysis and graduate students act as mentors. The project will support a public lecture on connecting groundwater DIN contamination to coastal eutrophication as part of UCONN's "Coastal Perspectives" and UNCW's "Planet Ocean" public lecture series. Successful efforts to augment groundwater anammox may result in remediation recommendations that can be transferred to regional managers through the Massachusetts USGS district office.