Abstract
We are evaluating the use of sequence markers specific for dehalogenating species to assess the dehalogenating potential of contaminated soils and to optimize soil bioremediation process parameters. Two systems contaminated with toxic and persistent chlorinated hydrocarbons have been investigated: a soil contaminated by dichloroethane (DCA) and a laboratory-scale, sequential anaerobic-aerobic process for the treatment of a soil contaminated with DDTs, chlorinated benzenes (CBs) and heavy metals, (mainly Hg and As). The microbial population profile of samples from these soils was analyzed by ARISA (Amplified Ribosomal Intergenic Spacer Analysis) and DGGE (Denaturing gradient get electrophoresis) of 16S rRNA genes. DGGE band sequencing detected the presence of bacteria previously associated with soils polluted by halogenated hydrocarbons or present in consortia active in the removal of these compounds. A PCR specific assay using primers for Dehalococcoides sp. showed the presence of this genus in the anaerobic phase of the soil treatment process.