Objective

Chlorinated solvents are prevalent and problematic groundwater contaminants because of their tendency to form large, dissolved-phase plumes, their recalcitrant nature, and the subsequent risk to human health. These sites are additionally problematic because of co-contamination, such as the presence of chlorinated ethanes and ethenes. Remediation is frequently based on bioremediation, which relies on establishing and maintaining significant populations of Dehalococcoides spp. to dehalogenate the chlorinated ethenes and Dehalobacter spp. to dehalogenate the chlorinated ethanes. However, to date, no method exists to rapidly and inexpensively quantify the population of these species on site in order to evaluate their activity, occurrence, and movement. All current monitoring methods are based on PCR (endpoint or quantitative PCR), which is performed in the laboratory on an expensive thermal cycler. The development of on-site detection assays would result in more rapid optimization of system performance (e.g., deciding if another round of biostimulation or bioaugmentation is necessary) and ultimately more cost-effective achievement of remedial goals.

The objective of this project is to develop a rapid, sensitive, and inexpensive field method to quantify Dehalococcoides and Dehalobacter spp. genes from groundwater samples on-site. Specifically, researchers will develop a loop mediated isothermal amplification (LAMP) methodology to rapidly quantify these organisms (via 16S rRNA and reductive dehalogenase genes) at field sites, without DNA extraction, using microfluidic chips in the Gene-Z (an inexpensive, handheld device).