title: Transcriptional response of Rhodococcus aetherivorans I24 to polychlorinated biphenyl-contaminated sediments.
abstract: We used a microarray targeting 3,524 genes to assess the transcriptional response of the actinomycete Rhodococcus aetherivorans I24 in minimal medium supplemented with various substrates (e.g., PCBs) and in both PCB-contaminated and non-contaminated sediment slurries. Relative to the reference condition (minimal medium supplemented with glucose), 408 genes were upregulated in the various treatments. In medium and in sediment, PCBs elicited the upregulation of a common set of 100 genes, including gene-encoding chaperones (groEL), a superoxide dismutase (sodA), alkyl hydroperoxide reductase protein C (ahpC), and a catalase/peroxidase (katG). Analysis of the R. aetherivorans I24 genome sequence identified orthologs of many of the genes in the canonical biphenyl pathway, but very few of these genes were upregulated in response to PCBs or biphenyl. This study is one of the first to use microarrays to assess the transcriptional response of a soil bacterium to a pollutant under conditions that more closely resemble the natural environment. Our results indicate that the transcriptional response of R. aetherivorans I24 to PCBs, in both medium and sediment, is primarily directed towards reducing oxidative stress, rather than catabolism.
authors.affiliation: Istituto di Chimica Agraria ed Ambientale, Università Cattolica del Sacro Cuore, Piacenza, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Puglisi
authors.forename: Matt J
authors.initials: MJ
authors.lastname: Cahill
authors.forename: Philip A
authors.initials: PA
authors.lastname: Lessard
authors.forename: Ettore
authors.initials: E
authors.lastname: Capri
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Sinskey
authors.forename: John A C
authors.initials: JA
authors.lastname: Archer
authors.forename: Paolo
authors.initials: P
authors.lastname: Boccazzi
mesh_terms: D001673:Biodegradation, Environmental; D003470:Culture Media; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D019015:Geologic Sediments / Q000382:microbiology*; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress; D011078:Polychlorinated Biphenyls / Q000378:metabolism*; D012329:RNA, Bacterial / Q000235:genetics; D012240:Rhodococcus / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D003470:Culture Media; D012329:RNA, Bacterial; D012989:Soil Pollutants; D011078:Polychlorinated Biphenyls