Advanced Environmental Molecular Diagnostics to Assess, Monitor, and Predict Microbial Activities at Complicated Chlorinated Solvent Sites
ER-2312
Objective
Bioremediation plays a crucial role in transforming and detoxifying chlorinated solvents and has demonstrated successes when implemented as a stand-alone technology at monitored natural attenuation (MNA), biostimulation, and bioaugmentation field sites or as a polishing step when physical-chemical treatment serves as the primary remedy. Molecular biological tools (MBTs) provide information about the presence and abundance of keystone dechlorinating bacteria (i.e., Dehalococcoides) and improve site assessment and bioremediation monitoring. Although benefits to microbial analysis are indisputable, uncertainty about how to interpret MBT results exists, and a consensus has not been reached regarding the value of MBTs for enhanced decision-making to accelerate paths toward site closures. The overarching objective of this project is to advance MBTs and their application to minimize biases and to more effectively assess, predict, monitor, optimize, and manage reductive dechlorination processes at contaminated Department of Defense (DoD) sites. Specifically, innovative high-throughput qPCR technology and environmental proteomics workflows will be combined to characterize dechlorinating microbial communities and activities (i.e., process rates).
Technical Approach
This research effort builds on the recent identification of keystone bacteria and reductive dechlorination biomarkers and capitalizes on unparalleled advances in analytical technologies. In light of current limitations of MBT approaches, high-throughput Open Array qPCR and environmental proteomics workflows will be designed and employed in parallel. Applying these tools to laboratory cultures will advance understanding of the requirements and constraints of keystone bacteria contributing to chlorinated solvent detoxification and provide a more complete and refined picture of the dechlorinating microbial community, its activity, and its response to perturbations. Open Array qPCR will reduce the analytical costs per biomarker and enable the design of site-tailored formats to facilitate data interpretation and further reduce costs, while eliminating ambiguity associated with data acquisition and interpretation. Field measurements will subsequently demonstrate the value of these advanced tools for diagnosing and optimizing remediation systems and for generating predictive understanding of system performance at DoD remediation sites.
Benefits
Open Array qPCR technology and environmental proteomics workflows will help identify parameters surrounding the feasibility and potential success of a microbial remedy, so that non-productive investments can be avoided, realistic performance predictions can be established, and bioremediation sites will be managed most efficiently to achieve early site closures. Proteomics directly measures the catalysts and, when integrated with the Open Array qPCR data, promises to provide information about dechlorination activity (i.e., rates) that is necessary to improve reactive transport models and predict contaminant longevity. With this information, remediation project managers (RPMs) can document whether performance goals can/cannot be met, optimize site management accordingly, or, if necessary, implement alternative treatment strategies (i.e., adaptive site management can be achieved). Developing a searchable database that contains geochemical, contaminant, hydrogeological, and microbial (e.g., Open Array and proteomics) information will enhance the demonstration of statistically significant correlations between measureable parameters and contaminant fate and longevity. Since Open Array qPCR technology mitigates biases associated with standard curve preparation and varying target amplification efficiencies, qPCR data collected from different sites and by different laboratories will be directly comparable. Hence, these new tools will increase confidence in MBT data, and the database will effectively showcase the value of these tools to RPMs and regulators. (Anticipated Project Completion - 2017)
Points of Contact
Principal Investigator
Dr. Frank Löffler
University of Tennessee
Phone: 865-974-4933
Fax: 865-974-4007
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.