Evidence for shifts in the structure and abundance of the microbial community in a long-term PCB-contaminated soil under bioremediation

► A small-scale bioremediation assay was designed to bioremediate the soil of a transformer station contaminated with PCBs. ► The impact of bioremediation on the soil microbial community was assessed by Ribosomal intergenic spacer analysis and quantitative PCR. ► Ribosomal intergenic spacer analysis revealed that bioremediation resulted in a shift in the structure of the total bacterial community. ► qPCR assays revealed that bioremediation modified the abundances of the 11 targeted bacterial taxa: Actinobacteria, Acidobacteria, α-, β- and γ-Proteobacteria, Bacteriodetes, Firmicutes, Gemmatimonadetes, Verrucomicrobia, Planctomycetes and Crenarchaeota ► Bioremediation was shown to stimulate the abundances of Actinobacteria, Bacteroidetes and α- and γ-Proteobacteria phyla but had a negative impact on the abundance of Acidobacteria.