We investigated the effects of copper on the structure and physiology of freshwater biofilm microbial communities.\ud For this purpose, biofilms that were grown during 4 weeks in a shallow, slightly polluted ditch were\ud exposed, in aquaria in our laboratory, to a range of copper concentrations (0, 1, 3, and 10 M). Denaturing\ud gradient gel electrophoresis (DGGE) revealed changes in the bacterial community in all aquaria. The extent\ud of change was related to the concentration of copper applied, indicating that copper directly or indirectly caused\ud the effects. Concomitantly with these changes in structure, changes in the metabolic potential of the heterotrophic\ud bacterial community were apparent from changes in substrate use profiles as assessed on Biolog plates.\ud The structure of the phototrophic community also changed during the experiment, as observed by microscopic\ud analysis in combination with DGGE analysis of eukaryotic microorganisms and cyanobacteria. However, the\ud extent of community change, as observed by DGGE, was not significantly greater in the copper treatments than\ud in the control. Yet microscopic analysis showed a development toward a greater proportion of cyanobacteria\ud in the treatments with the highest copper concentrations. Furthermore, copper did affect the physiology of the\ud phototrophic community, as evidenced by the fact that a decrease in photosynthetic capacity was detected in\ud the treatment with the highest copper concentration. Therefore, we conclude that copper affected the physiology\ud of the biofilm and had an effect on the structure of the communities composing this biofilm
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.