Transcriptional response of Rhodococcus aetherivorans I24 to polychlorinated biphenyl-contaminated sediments

Microb Ecol. 2010 Oct;60(3):505-15. doi: 10.1007/s00248-010-9650-5. Epub 2010 Apr 6.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biodegradation, Environmental
  • Culture Media
  • Gene Expression Regulation, Bacterial
  • Genes, Bacterial
  • Geologic Sediments / microbiology*
  • Oligonucleotide Array Sequence Analysis
  • Oxidative Stress
  • Polychlorinated Biphenyls / metabolism*
  • RNA, Bacterial / genetics
  • Rhodococcus / genetics*
  • Rhodococcus / metabolism
  • Sequence Analysis, DNA
  • Soil Microbiology*
  • Soil Pollutants / metabolism*
  • Transcription, Genetic

Substances

  • Culture Media
  • RNA, Bacterial
  • Soil Pollutants
  • Polychlorinated Biphenyls