Microbial diversity and resistance to copper in metal-contaminated lake sediment

Microb Ecol. 2003 Feb;45(2):191-202. doi: 10.1007/s00248-002-1035-y. Epub 2003 Jan 28.


Contamination of habitats with heavy metals has become a worldwide problem. We describe herein the analysis of lake sediment contaminated with high concentrations of copper as a consequence of mine milling disposal over a 100-year period. Copper concentrations in the sediment were found to vary with depth and ranged from 200 to 5500 ppm. Analysis of the microbial community with T-RFLP identified a minimum of 20 operational taxonomic units (OTU). T-RFLP analysis along a depth profile detected as many as nine shared OTUs across 15 centimeters, suggesting a conservation of community structure over this range. Only two genera, Arthrobacter and Ralstonia, were detected among 50 aerobic copper-resistant isolates cultivated on R2A, one of which (Ralstonia sp.) was characterized by the sequestration of copper, identified by electron diffraction scanning, in growing colonies. Scanning electron microscopy showed changes to the outer envelope of the cells when grown in the presence of copper. The copper-resistant Ralstonia isolates were also resistant to Ni, Cd, and Zn, showing two patterns of phenotypic resistant to these three metals in which either resistance to Zn or Ni was expressed in an isolate but never both.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Arthrobacter / drug effects
  • Arthrobacter / growth & development*
  • Arthrobacter / metabolism
  • Base Sequence
  • Copper / analysis*
  • Copper / toxicity
  • Cupriavidus necator / drug effects
  • Cupriavidus necator / genetics
  • Cupriavidus necator / growth & development*
  • Cupriavidus necator / metabolism
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • Fresh Water / microbiology*
  • Geologic Sediments / chemistry
  • Geologic Sediments / microbiology*
  • Microscopy, Electron, Scanning
  • Microscopy, Phase-Contrast
  • Molecular Sequence Data
  • Phylogeny
  • Polymerase Chain Reaction
  • Polymorphism, Restriction Fragment Length
  • RNA, Ribosomal, 16S / chemistry
  • RNA, Ribosomal, 16S / genetics
  • Sequence Alignment
  • Water Microbiology
  • Water Pollutants, Chemical / analysis*
  • Water Pollutants, Chemical / toxicity


  • DNA, Bacterial
  • RNA, Ribosomal, 16S
  • Water Pollutants, Chemical
  • Copper