Molecular Genetic Characterization of Contaminated Environments as a Tool for the Assessment of Remediation Technology

Purdue University, West Lafayette IN

Investigators

Abstract

0302645 Nies Molecular genetic analysis of microbial community structure and function can provide a direct and powerful tool to assess stressed, impacted, and recovering ecosystems. This information can improve bioremediation system design and operation, evaluation of monitored natural attenuation (MNA) and resource allocation, and it will increase the use of sound science in decision making and regulatory oversight. Intellectual Merit. We have developed a set of primers and a real-time PCR protocol to detect and enumerate aromatic oxygenase genes, and have used them in parallel with PCR-DGGE community analysis, to assess the feasibility of using this biotechnology as a bioremediation assessment and monitoring tool. The detection of oxygenase genes yields direct insight into the assimilative function of the local ecosystem, i.e. the occurrence of aerobic biodegradation of aromatic hydrocarbons. Our primers have been tested in well controlled experiments with pure cultures, in soil microcosms, and on samples from two field sites. Tracking catabolic genes involved in the biodegradation of priority pollutants can be used to optimize remediation systems and evaluate MNA. Reliable in-situ methods currently do not exist to evaluate the effectiveness of the components used for bioremediation aeration, such as vacuum pumps, air spargers, or oxygen releasing amendments. The direct measurement of genes encoding aromatic oxygenases would provide an effective tool for monitoring engineered aeration systems and for MNA. Aromatic oxygenase genes were chosen as indicators because they play a key role in the biodegradation of BTEX, the pollutants of principal concern at gasoline-contaminated sites. The utilization of expensive aeration technologies and oxygen releasing amendments could be significantly optimized by the development of modern biotechnology tools. We propose to evaluate the feasibility of using molecular genetic characterization of the microbial community structure, and catabolic function, to advance the state-of-the-art of LUST site remediation in a field-scale university-industry collaboration. Over a three year period, our interdisciplinary university-industry team proposes to conduct a research project that will obtain field performance data about this recently developed tool for monitoring petroleum contaminated sites. We expect that sites of different 'ages,' geochemistry and geology will have characteristic and detectable molecular signatures.