Grantee Research Project Results

Microbial Indicators of Bioremediation Potential and Success

EPA Grant Number: R828770C009
Subproject: this is subproject number 009 , established and managed by the Center Director under grant R828770
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Duke University Center for Environmental Implications of NanoTechnology
Center Director: Wiesner, Mark R.
Title: Microbial Indicators of Bioremediation Potential and Success
Investigators: Banks, M. Katherine , Alleman, Jim
Institution: Purdue University
EPA Project Officer: Aja, Hayley
Project Period: October 1, 2001 through September 30, 2002
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (2001) Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management

Objective:

Recent scientific advances have made it possible to use molecular biological techniques for assessment of microbial communities in complex environmental systems. Molecular techniques, such as PCR amplification, cloning, and sequencing of ribosomal RNA genes, have recently been embraced by the environmental science community as important tools for predicting soil and water remediation success. The focus of this project is to evaluate the potential use of a suite of microbiological techniques for assessment of bioremediation. Numerous methods are available for evaluation of microbial biomass in soil. Traditional enrichment culture-based techniques, such as heterotrophic plate counts, are frequently used; however, biases may be introduced by media type and richness, presence or absence of oxygen, and numerous other factors. Such techniques are thought to reveal as little as ten percent of the total microbial diversity in soil. For this reason, innovative methods have been developed to more completely describe soil microbial diversity. Molecular methods, such as denaturing gradient gel electrophoresis (DGGE), rely on genetic differences to draw distinctions between microbes and microbial populations. Chemical extraction of phospholipid-fatty acids from soil can provide both a description of the diversity in that soil and an estimate of the microbial biomass present. Finally, most probable number (MPN), a specialized enrichment technique utilizing substrates of interest, gives an estimate of the number of organisms in an environment capable of degrading specific contaminants. Taken individually, DGGE, phospholipid-fatty acid analysis, and MPN are all useful tools for understanding microbial communities. In combination, however, they are likely to yield extensive information on microbial biomass and community diversity. Furthermore, they provide the capability to pinpoint dominant groups of organisms and to assess the microbial community's ability to degrade contaminants. Integration of these diverse methods represents a potentially powerful tool for characterization - and, ultimately, optimization - of bioremediation systems.

Approach:

To determine specifically how diversity is related to bioremediation efficiency, microbial contaminant degraders and microbial community structure in bioremediated soil will be evaluated. Contaminated soil from at least seven bioremediation/phytoremediation field trials will be collected and analyzed. Data generated from the community analyses will be compared with the MPN of contaminant degraders and percent removal of the contaminant to date. If strong correlations are identified, the protocol will be developed into a comprehensive screening methods manual to be used extensively for bioremediation projects.

Expected Results:

Bioremediation, microbial degraders, diversity.

Supplemental Keywords:

RFA, Scientific Discipline, Waste, Water, Contaminated Sediments, Environmental Chemistry, Microbiology, Environmental Microbiology, Hazardous Waste, Bioremediation, Molecular Biology/Genetics, Hazardous, degradation, genetics, microbial degradation, bioavailability, biodegradation, contaminated sediment, microbes, contaminated soil, denaturing gradient gel electrophoresis, bioremediation of soils, contaminants in soil, biochemistry, phytoremediation

Progress and Final Reports:

Final

Main Center Abstract and Reports:

R828770    Duke University Center for Environmental Implications of NanoTechnology

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R828770C001 Technical Outreach Services for Communities
R828770C002 Technical Outreach Services for Native American Communities
R828770C003 Sustainable Remediation
R828770C004 Incorporating Natural Attenuation Into Design and Management Strategies For Contaminated Sites
R828770C005 Metals Removal by Constructed Wetlands
R828770C006 Adaptation of Subsurface Microbial Biofilm Communities in Response to Chemical Stressors
R828770C007 Dewatering, Remediation, and Evaluation of Dredged Sediments
R828770C008 Interaction of Various Plant Species with Microbial PCB-Degraders in Contaminated Soils
R828770C009 Microbial Indicators of Bioremediation Potential and Success