US EPA

3996537 

Book/Book Chapter 

Using a molecular approach to monitor a bioaugmentation pilot 

Hendrickson, ER; Starr, MG; Elberson, MA; Payne, JA; Mack, EE; Huang, HB; Mcmaster, ML; Ellis, DE 

2001 

BIOREMEDIATION SERIES 

6 

8 

43-51 

WOS:000175098200006 

The Bioremediation Consortium of the Remediation Technologies Development Forum (RTDF) carried out a successful anaerobic bioaugmentation pilot to bioremediate a chloroethene Tetrachloroethene (PCE), Trichloroethene (TCE) and 1,2 cis-dichloroethene (cDCE) contaminated aquifer at Kelly Air Force Base near San Antonio, Texas (TX). An anaerobic dechlorinating enrichment culture, KB-1, was injected into the ground to duplicate the successful bioaugmentation pilot at Dover AFB, Delaware (DE) (1997-1999). The KB-1 community structure has been analyzed and shown to have a Dehalococcoides ethenogenes-like species present in its community structure. Dehalococcoides ethenogenes (DHE) is an organism described by Maymo-Gatell et al. (Science 276, 1568-1571, 1997). DHE was shown to dechlorinate PCE and TCE by removing all the chlorine atoms to form ethene, through a process known as dehalorespiration. Dehalococcoides ethenogenes-like (DHE-like) organisms detected in samples from approximately 30 different sites in North America and Europe have shown 16S rRNA gene sequences (rDNA) with signature sequences that are unique to the sampling site. This was found true for the KB-1 DHE-like organism. We have developed a specific 16S rRNA polymerase chain reaction (PCR) assay to detect DHE-like organisms. Using the PCR assay and 16S rDNA sequence information, groundwater samples were monitored during the course of the Kelly pilot study. The DHE-like organism was not detected in the control groundwater that had been given electron donors (methanol and acetate). After bioaugmentation, PCR analysis of groundwater from monitoring wells detected the DHE-like organism. Detection first appeared in the injection well and then in down gradient monitoring wells (first in the nearest well and then in the well wells further down gradient), The DHE-like organism was detected in the extraction wells, two months after bioaugmentation. Together, with field data from monitoring wells that have demonstrated dechlorination of PCE to ethene, the PCR and sequence data suggest that the bioaugmentation culture, KB-1, had colonized the test plot in the Kelly AFB chloroethene contaminated aquifer.