Journal of Applied Microbiology, Vol.107, No.6, 1883-1893, 2009
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.
Keywords:2;4-dichlorophenol;rDNA;rRNA;soil bacterial community structure;terminal restriction fragment length polymorphism