Dehalococcoides (DHC & Functional Genes) ER

Use CENSUS^® qPCR or QuantArray^®-Chlor to quantify Dehalococcoides and functional genes responsible for reductive dechlorination of PCE, TCE, DCE, vinyl chloride and other chlorinated compounds.

Dehalococcoides mccartyi was the first bacterial group isolated and proven to be capable of complete anaerobic dechlorination of chlorinated ethene compounds to ethene. Since then, CENSUS® qPCR and QuantArray®-Chlor quantification of Dehalococcoides and reductive dehalogenase genes (TCE, BVC, and VCR) have become an indispensable component of assessment, remedy selection, and performance monitoring at chlorinated solvent sites in North America and around the world. In fact, Lu et al. (2006) have proposed using a Dehalococcoides concentration of 1.0E+04 cells/mL as a screening criterion to identify sites where biological reductive dechlorination will proceed at “generally useful” dechlorination rates.

HOW TO USE DEHALOCOCCOIDES & FUNCTIONAL GENE RESULTS:

Along with contaminant concentrations and geochemical parameters, concentrations of Dehalococcoides and functional genes are key components of remedy selection and performance monitoring at sites impacted by chlorinated ethenes (PCE, TCE, cis-DCE, vinyl chloride) and other chlorinated compounds.

During Remedy Selection:

If Dehalococcoides (DHC) concentrations are less than 1.0E+04 cells/mL and concentrations of vinyl chloride reductase genes (BVC or VCR) are near or below detection limits, reductive dechlorination is unlikely to occur at a generally useful rates under existing conditions.

Biostimulation (electron donor addition): If Dehalococcoides (DHC) are detected even at low concentrations in most wells within the source area, electron donor injection may stimulate growth of these key halorespiring bacteria and promote reductive dechlorination.  Bioaugmentation would not be necessary.

Bioaugmentation (electron donor + commercial culture): If Dehalococcoides are not detected even at low concentrations in most wells within the source area, bioaugmentation may be needed.

For Performance Monitoring:

Substantial increases in the concentrations of Dehalococcoides and functional genes demonstrate the effectiveness of electron donor injection (biostimulation) or bioaugmentation.  For generally useful dechlorination rates, Dehalococcoides concentrations should increase to and remain greater than 1.0E+04 cells/mL and vinyl chloride reductase genes (BVC or VCR) should also be detected.