ASSESSING DEHALOGENASE ACTIVITIES UTILIZING INTEGRATING QUANTITATIVE PCR AND MICROARRAYS DURING PCE BIOREMEDIATION : THE CONTRUCTION OF A NEW DEGRADATION MODEL

Abstract

International audienceThe bioremediation of groundwater contaminated by tetrachloroethylene (PCE), a widely used chlorinated solvent, can lead to toxic metabolites. In order to evaluate the entire degradation of PCE, we quantify the mRNA of the genes responsible for the degradation of each metabolite by using quantitative PCR and reverse transcriptase quantitative PCR, and correlated their expression levels to the bacterial community structure observed by phylogenic microarray hybridization. This approach was applied to 120 microcosms in which we added lactate, molasses, or soybean oil. These organic substrates are often used to induce reductive dechlorination during bioremediation in situ. These different organic substrates cause changes in the bacterial community structure, and the production of hazardous metabolites depends on the organic substrate added. In order to determine whether relevant biomarkers can signal the hazardous metabolite production, we correlated quantitative PCE results and phylogenic microarrays hybridizations under the different organic substrate conditions. In addition, we incorporated the qPCR and RTqPCR data in a PCE degradation kinetic model, which takes into account bacterial activity, hydrogeological and geochemical data