Biosensors for detection of mercury in contaminated soils
Department of Biotechnology, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
Department of Environmental Chemistry and Microbiology, National Environmental Research Institute, P.O. Box 358, DK-4000 Roskilde, Denmark
Limburgs Universitair Centrum, Environmental Biology, Universitaire Campus, building D, B-3590 Diepenbeek, Belgium
European Commission (EC)/Joint Research Centre (JRC), Institute for Reference Materials and Measurements (IRMM), Reference Materials Unit (RM), Retieseweg, B-2440 Geel, Belgium
Biosensors based on whole bacterial cells and on bacterial heavy metal binding protein were used to determine the mercury concentration in soil. The soil samples were collected in a vegetable garden accidentally contaminated with elemental mercury 25 years earlier. Bioavailable mercury was measured using different sensors: a protein-based biosensor, a whole bacterial cell based biosensor, and a plant sensor, i.e. morphological and biochemical responses in primary leaves and roots of bean seedlings grown in the mercury-contaminated soil. For comparison the total mercury concentration of the soil samples was determined by AAS. Whole bacterial cell and protein-based biosensors gave accurate responses proportional to the total amount of mercury in the soil samples. On the contrary, plant sensors were found to be less useful indicators of soil mercury contamination, as determined by plant biomass, mercury content of primary leaves and enzyme activities.