Adaptation of Subsurface Microbial Biofilm Communities in Response to Chemical Stressors

EPA Grant Number: R828770C006
Subproject: this is subproject number 006 , 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: HSRC (2001) - Midwest Hazardous Substance Research Center
Center Director: Banks, M. Katherine
Title: Adaptation of Subsurface Microbial Biofilm Communities in Response to Chemical Stressors
Investigators: Bishop, Paul , Love, Nancy , Stevens, Am
Current Investigators: Love, Nancy , Stevens, Am
Institution: University of Cincinnati , Virginia Polytechnic Institute and State University
Current Institution: Virginia Polytechnic Institute and State University , University of Cincinnati
EPA Project Officer: Lasat, Mitch
Project Period: October 1, 2001 through September 30, 2003
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (2001) RFA Text |  Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management

Objective:

Effective restoration of contaminated subsurface environments requires a thorough understanding of how the biota in natural systems is structured and functions. A substantial effort has been put forth over the past few decades to improve our understanding of catabolic biodegradative processes, which play a critical role in the restoration of environments that have been contaminated by hazardous wastes. However, if we are to restore ecosystems to a natural state, it is necessary to develop a more complete conceptual model of how microbial communities are structured and function both during the remediation process and after it is complete. An important component of this understanding involves moving beyond studying microbial catabolism and toward other metabolic processes that play a critical role in defining the structure and function of microbial communities that are exposed to hazardous wastes. Microorganisms have evolved mechanisms that either protect the cell or remediate cell damage due to the presence of toxic chemicals (stressors) at sublethal concentrations. The structure and function of microbial biofilm communities, which are exposed to chemical stressors over long time periods, are influenced through the activation of selected stress responses. We propose to study the short and long-term impact of two model electrophilic hazardous chemicals (pentachlorophenol (PCP) and cadmium) on the structure and function of aerobic biofilm communities such as those existing in contaminated subsurface environments. We will focus on studying a specific stress response, the glutathione-gated potassium efflux (GGKE) system, which is activated in response to electrophilic chemical stressors. The matrix of environmentally-relevant chemical stressors has been selected for this study so that the relative roles of catabolism versus the GGKE system on biofilm community adaptation during restoration of contaminated sites can be determined.

Approach:

Biofilm structures will be characterized by using microelectrodes to follow important chemical gradients within the biofilms, and fluorescent in situ hybridization (FISH) coupled with confocal laser scanning microscopy (CLSM) to track the location and activity of selected microorganisms. Biofilm function will be characterized by monitoring the fate of the chemical stressors (catabolism or abiotic sorption) and the activation of the GGKE stress mechanism that responds to electrophilic chemical stressors.

Expected Results:

The impact of this work will help improve our understanding of how subsurface biofilm communities respond to chemical stressors that are likely to be present at hazardous waste sites. Ultimately, these results can be used to determine more effective ways to insure proper environmental conditions are present for successful soil bioremediation.

Publications and Presentations:

Publications have been submitted on this subproject: View all 4 publications for this subprojectView all 108 publications for this center

Supplemental Keywords:

fluorescent in situ hybridization (FISH), confocal laser scanning microscopy (CLSM), microbial biofilm communities, electrophillic chemical stressors., RFA, Scientific Discipline, Toxics, Waste, Water, Chemical Engineering, Contaminated Sediments, Environmental Chemistry, Environmental Microbiology, Hazardous Waste, Bioremediation, Molecular Biology/Genetics, Hazardous, 33/50, Environmental Engineering, microbiology, biofilm, microbial biofilm, microbial degradation, genetics, catabolic biodegradation, cadmium & cadmium compounds, PCP, bioavailability, biodegradation, laser scanner microscopy, contaminated sediment, microbes, contaminated soil, contaminants in soil, fluorescent in situ hybridization, bioremediation of soils, biochemistry, toxic chemicals, phytoremediation, cadmium

Progress and Final Reports:

  • 2002 Progress Report
  • Final

  • Main Center Abstract and Reports:

    R828770    HSRC (2001) - Midwest Hazardous Substance Research Center

    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