Identifying Biomarkers to Optimize Bioremediation Approaches for Contaminated Groundwater

过去的活动导致许多地下蓄水层受到四氯乙烯、三氯乙烯和1，4-二氧六环的污染。这些污染物是有问题的，因为它们对人类健康的风险。不幸的是，目前净化地下水的方法对这些污染物并不成功。作为另一种清洁方法，科学家们探索了使用细菌来生物降解这些污染物。然而，人们对地下水中这些细菌的身份和丰度知之甚少。如果没有这些信息，就很难预测去除污染物所需的时间。本研究的具体目标是确定负责1，4-二氧六环和氯化溶剂在地下水条件下生物降解的细菌。了解地下水中细菌的数量，将有助于对受污染的地下水采取更有效的管理办法。这项研究将通过密歇根州路易斯斯托克斯少数民族参与联盟涉及代表性不足的少数民族本科生。此外，研究成果也将纳入高中工程学院的活动中。总之，这些教育推广活动将有助于提高国家的科学知识和增加STEM领域的多样性。 由于氯化溶剂、其代谢物和1，4-二氧六环对人类健康构成风险，而且缺乏同时清除所有化学品的补救办法，因此许多场址受到氯化溶剂、其代谢物和1，4-二氧六环的共同污染尤其成问题。虽然许多研究都是针对氯代溶剂的修复，但对1，4-二氧六环生物修复的潜力知之甚少。在这里，总体目标是开发生物标志物，以优化地下水生物修复方法在氯化溶剂和1，4-二氧六环共污染的网站。具体目标是：i）使用稳定同位素探测确定哪些微生物负责在产甲烷条件下从1，4-二氧杂环己烷中吸收碳，并生成用于预测原位去除的方法/数据，ii）确定地下水中原位好氧1，4-二氧杂环己烷生物降解的生物标志物，iii）确定哪些生物标志物适用于好氧共代谢氯化乙烯降解。这项研究将包括通过密歇根州路易斯斯托克斯少数民族参与联盟代表性不足的少数民族本科生。此外，本科生将参加工程暑期本科生研究体验计划（Ensure）的一部分。确保是一个为期10周的计划，涉及专业发展活动，指导学生在一个研究项目和参与校园范围内的研讨会的研究。此外，活动将包括K-12外展计划的合作努力，如高中工程学院（夏季提供）。该项目还将加强研究生一级的教育工作者发展。设计的生物标志物将使补救社区，以确定这些功能基因是否存在于他们的网站，如果是这样，量化其丰度，并确定污染物去除和网站close.This奖项的预测时间反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Past activities have resulted in the contamination of many groundwater aquifers with tetrachloroethene, trichloroethene, and 1,4-dioxane. These contaminants are problematic because of their risks to human health. Unfortunately, current methods to clean-up groundwater have not been successful for these pollutants. As an alternative clean-up approach, scientists have explored the use of bacteria to biodegrade these pollutants. However, little is known about the identity and abundance of these bacteria in the groundwater. Without this information, it is difficult to predict the time required for contaminant removal. The specific goals of this research are to identify bacteria responsible for 1,4-dioxane and chlorinated solvent biodegradation under conditions in the groundwater. Knowledge concerning the quantity of bacteria in groundwater will result in more effective management approaches for contaminated groundwater. The research will involve underrepresented minority undergraduates through the Michigan Louis Stokes Alliance for Minority Participation. In addition, research results will also be incorporated into activities at the High School Engineering Institute. Together, these educational outreach activities will help improve the Nation's scientific knowledge and increase diversity in STEM fields. The co-contamination of many sites with the chlorinated solvents, their metabolites and 1,4-dioxane is particularly problematic because of the risks to human health and the lack of remediation approaches to remove all chemicals concurrently. Although much research has been directed towards the remediation of the chlorinated solvents, less is known about the potential for 1,4-dioxane bioremediation. Here, the overall objective is to develop biomarkers to optimize groundwater bioremediation approaches at chlorinated solvent and 1,4-dioxane co-contaminated sites. The specific objectives are to i) determine which microorganisms are responsible for carbon uptake from 1,4-dioxane under methanogenic conditions using stable isotope probing and generate methods/data for predicting in situ removal, ii) identify biomarkers for in situ aerobic 1,4-dioxane biodegradation in groundwater, and iii) determine which biomarkers are appropriate for aerobic co-metabolic chlorinated ethene degradation. The research will include underrepresented minority undergraduates through the Michigan Louis Stokes Alliance for Minority Participation. Also, undergraduates will participate as part of the Engineering Summer Undergraduate Research Experience Program (EnSURE). EnSURE is a 10-week program involving professional development activities, mentoring of students in a research project and participation in a campus-wide symposium for research. Further, activities will include collaborative efforts in K-12 outreach programs, such as the High School Engineering Institute (offered during the summer). The project will also enhance educator development at the graduate student level. The designed biomarkers will enable the remediation community to determine if these functional genes are present at their sites and, if so, quantify their abundance and determine the predicted time for contaminant removal and site closure.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.