Three common metal contaminants of urban runoff (Zn, Cu & Pb) accumulate in freshwater biofilm and modify embedded bacterial communities.
We investigated the absorption rates of zinc, copper and lead in freshwater biofilm and assessed whether biofilm bacterial populations are affected by exposure to environmentally relevant concentrations of these metals in flow chamber microcosms. Metals were rapidly accumulated by the biofilm and then retained for at least 14 days after transfer to uncontaminated water. Changes in bacterial populations were assessed by Automated Ribosomal Intergenic Spacer Analysis (ARISA) and 16S rRNA gene clone libraries. Significant differences in bacterial community structure occurred within only three days of exposure to metals and remained detectable at least 14 days after transfer to uncontaminated water. The rapid uptake of stormwater-associated metals and their retention in the biofilm highlight the potential role of biofilms in the transfer of metals to organisms at higher trophic levels. The sensitivity of stream biofilm bacterial populations to metal exposure supports their use as an indicator of stream ecological health.
Environmental Microbiology Research Group, School of Biological Sciences, The University of Auckland, Private Bag 92-019, Auckland 1010, New Zealand. panc002@ec.auckland.ac.nz
Pierre-Yves
PY
Ancion
Gavin
G
Lear
Gillian D
GD
Lewis
D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D044822:Biodiversity; D018441:Biofilms; D002947:Cities; D003300:Copper / Q000032:analysis / Q000378:metabolism; D005618:Fresh Water / Q000737:chemistry / Q000382:microbiology*; D007854:Lead / Q000032:analysis / Q000378:metabolism; D019216:Metals, Heavy / Q000378:metabolism*; D008969:Molecular Sequence Data; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D015032:Zinc / Q000032:analysis / Q000378:metabolism
D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D007854:Lead; D003300:Copper; D015032:Zinc