PCE- and VC-dechlorinating bacteria from the Brunswick formation, NJ

The dechlorination potential of native microbial populations using enrichments of groundwater and sediment fines from a PCE-contaminated fractured rock aquifer on the Rutgers University Busch Campus in Piscataway, NJ, was studied. While the groundwater was being pumped from the monitoring well, the tubing was extended to the bottom of the well to obtain fine sediments that accumulated there. Addition of lactate and butyrate stimulated rapid onset of tetrachloroethylene dechlorination to ethylene in microcosms. Little dechlorination was observed in live controls not receiving electron donors. Initial molecular characterization was performed on 16S rRNA genes using polymerase chain reaction (PCR) coupled to denaturing gradient gel electrophoresis (DGGE). Major DGGE bands were sampled, reamplified and re-run to ensure purity prior to sequencing. Two major bands yielded sequences corresponding to two different Dehalococcoides-like organisms. Both bands appeared in the PCE-amended enrichments and only one major band appeared in the VC-amended enrichments. The aquifer was not currently undergoing enhanced remediation; however, it harbors a dehalorespiring community capable of dechlorinating PCE to ethylene. This is an abstract of a paper presented at the 8th International In Situ and On-Site Bioremediation Symposium (Baltimore, MD 6/6-9/2005).