Assessment of heavy metal bioavailability in contaminated sediments and soils using green fluorescent protein-based bacterial biosensors.
A green fluorescent protein (GFP)-based bacterial biosensor Escherichia coli DH5alpha (pVLCD1) was developed based on the expression of gfp under the control of the cad promoter and the cadC gene of Staphylococcus aureus plasmid pI258. DH5alpha (pVLCD1) mainly responded to Cd(II), Pb(II), and Sb(III), the lowest detectable concentrations being 0.1 nmol L(-1), 10 nmol L(-1), and 0.1 nmol L(-1), respectively, with 2h exposure. The biosensor was field-tested to measure the relative bioavailability of the heavy metals in contaminated sediments and soil samples. The results showed that the majority of heavy metals remained adsorbed to soil particles: Cd(II)/Pb(II) was only partially available to the biosensor in soil-water extracts. Our results demonstrate that the GFP-based bacterial biosensor is useful and applicable in determining the bioavailability of heavy metals with high sensitivity in contaminated sediment and soil samples and suggests a potential for its inexpensive application in environmentally relevant sample tests.
Liao
Vivian Hsiu-Chuan
VH
Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan, ROC. vivianliao@ntu.edu.tw
Chien
Ming-Te
MT
Tseng
Yuen-Yi
YY
Ou
Kun-Lin
KL
D001682:Biological Availability; D015374:Biosensing Techniques; D002104:Cadmium / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D004926:Escherichia coli / Q000378:metabolism*; D019015:Geologic Sediments; D049452:Green Fluorescent Proteins; D007854:Lead / Q000032:analysis; D019216:Metals, Heavy / Q000032:analysis*; D008856:Microscopy, Fluorescence; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis*; D014001:Tin / Q000032:analysis; D015032:Zinc / Q000032:analysis
D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D049452:Green Fluorescent Proteins; D007854:Lead; D014001:Tin; D015032:Zinc