Quantitative environmental monitoring of PCE dechlorinators in a contaminated aquifer and PCE-fed reactor (Dehalococcoides, Desulfuromonas)

Understanding the mechanisms by which natural attenuation of halogenated compounds occurs is important to the fields of bioremediation and environmental toxicology. Of the halogenated organic compounds in the environment, the chlorinated ethenes, PCE, TCE, -DCE, VC are of importance. Dehalococcoides ethenogenes and Dehalococcoides spp. strain FL2 are the only isolates capable of dechlorinating PCE to ethene. The objective of this research was to utilize Real Time PCR (RTm PCR) to detect and quantify specific chlorinated ethene degraders in environmental systems. RTm PCR was capable of detecting and quantifying the Dehalococcoides and Desulfuromonas groups of PCE dechlorinators. 16S and tceA gene primers and probes specific to these groups of organisms were designed and tested to assure specificity for the organisms of interest. PCE contaminated aquifer core samples were used to test the ability of RTm PCR to detect the key dechlorinators in an environmental sample. The population of Dehalococcoides was quantified in a large-scale reactor along with the mRNA of its dehalogenase through several feeding cycles. RTm PCR was shown to be an accurate and efficient quantitative tool in the detection of dechlorinating microorganisms.