Duration: 10/01/2000 to 09/30/2005

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Statement of Issues and Justification

Related, Current and Previous Work

Objectives

1. To determine the geographic and temporal variability of E. coli ribotypes in the United States.
   
2. To determine relationships among microbial taxonomic and functional diversity, contaminant bioavailability, and remediation rates for different organic-contaminated soils.
   
3. To characterize taxonomic and functional diversity of bacteria and mycorrhizae in distrubed lands and urban landscapes.
   
4. 
   

Methods

Measurement of Progress and Results

Outputs

Outcomes or Projected Impacts

• 1. NY BST efforts have brought to light that failing wastewater treatment facilities in the region studied are likely contributing to elevated levels of total coliforms and enterococci in the watershed.
• 2. Results from River Yagüez are almost completed, and there is indication that significant variation in microbial populations exists. These indicate that factors are affecting microbial biomass.
• 3. Results of the BST studies confirm that ribotyping of Enterococcus faecalis is a useful and highly discriminatory approach to BST, but that it must be combined with a targeted sampling protocol in order to overcome the high geographic and temporal variability in ribotypes.
• 4. Although differences in survival exist among fecal enterococcal species and subspecies, and differences exist between locations, none of the Enterococcus species or subspecies survived sufficiently well in moist sediment to serve as a reservoir of long-past human and nonhuman fecal contamination. Therefore, the American Public Health Association rule that fecal indicators not persist in the environment held.
• 5. However, results from desiccation experiments suggest that enterococcal survival and potential regrowth during conditions of desiccation may represent a source of relatively long-past human or nonhuman fecal contamination. Under these circumstances, the American Public Health Association rule that fecal indicators not persist in the environment fails. The implications of these results for testing fecal contamination of water are troubling.
• 6. The watershed project in Virginia will provide a ?real-world? evaluation of three source tracking methods and two indicator organisms over time, and offers the opportunity to compare the size and origin of sediment populations as well as those in water samples
• 7. The development of a method to detect optical brighteners will permit detection of fluorescent plumes from failing onsite systems or leaking sewer pipes, and should be adaptable as a instantaneous presence-absence test for human-derived pollution in recreational waters such as beaches.
• 8. The most important finding in our comparison of genotypic methods to determine a source of fecal contamination in the environment is the need to use the method most appropriate for the question being asked and is dependent on cost and level of specificity required.
• 9. The development of a species-specific primer that works in a biosensor to detect synthetic sequences of Enterococcus faecalis is a positive first step in the development of an inexpensive new technique to detect pathogens from the environment.
• Results of the studies under objective 2 can guide development of bioremediation strategies that maximize the use of natural resources while minimize environmental risk.
• 11. We believe that this is the first report of a specific group of bacteria adapting to interact with humic acids in such a way that PAH sorbed by these environmental polymers is bioavailable.
• 12. These organisms may have value as bioremediation inoculants, and have an important role in the biodegradation processes affecting the fate of PAH in the environment.
• 13. Enumeration of aromatic oxygenase genes by real-time PCR combined with chemical analysis required in corrective action plans could be used to directly assess biodegradation of priority pollutants which can help provide more accurate assessment of biodegradation, facilitate assessment of the impact of remediation technologies on indigenous microbial populations, and enhance studies of contaminated site ecology.
• 14. Data from the phytoremediation experiment will help understand how establishment of grasses and management practices affect microbial dynamics over the long-term and thus allow us to gather insight and interpret the process and extent of ecosystem recovery during remediation.
• 15. Biodegradative strains isolated from RDX/TNT contaminated soils have been obtained, which ma

Milestones

Projected Participation

View Appendix E: Participation

Outreach Plan

Organization/Governance

Literature Cited

Attachments

Land Grant Participating States/Institutions

AL, AR, CO, DE, FL, GA, IN, KY, MD, NC, NY, OK, TX, VA, WI, WV

Non Land Grant Participating States/Institutions

ARS, Florida International University, U.S. Army, University of Saskatchewan, Canada, USDA-ARS/Georgia