Comparison of DNA‐ and RNA‐based bacterial community structures in soil exposed to 2,4‐dichlorophenol

Aims: To examine the effect of the pollutant 2,4‐dichlorophenol on DNA‐ and RNA‐based bacterial communities in soil. Methods and Results: Soil was exposed to 100 mg kg^?1 of 2,4‐dichlorophenol (2,4‐DCP), and degradation was monitored over 35 days. DNA and RNA were coextracted, and terminal restriction fragment length polymorphism (T‐RFLP) was used to report changes in bacterial communities in response to the presence of the chlorophenol. The phylogenetic composition of the soil during degradation was determined by creating a clone library of amplified 16S rRNA sequences from both DNA and reverse‐transcribed RNA from exposed soil. Resulting clones were sequenced, and putative identities were assigned. Conclusions: A significant difference between active (RNA‐based) and total (DNA‐based) bacterial community structure was observed for both T‐RFLP and phylogenetic analyses in response to 2,4‐DCP, with more pronounced changes seen in RNA‐based communities. Phylogenetic analysis indicated the dominance of Proteobacteria in both profiles. Significance and Impact of the Study: This study describes the response of soil bacterial communities to the addition of the xenobiotic compound 2,4‐DCP, and highlights the importance of including RNA‐based 16S rRNA analysis to complement any molecular study in a perturbed soil.