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.

[1]  S. Silver,et al.  CadC, the transcriptional regulatory protein of the cadmium resistance system of Staphylococcus aureus plasmid pI258 , 1995, Journal of bacteriology.

[2]  R. Burlage,et al.  Bioluminescent sensors for detection of bioavailable Hg(II) in the environment , 1993, Applied and environmental microbiology.

[3]  D. Giedroc,et al.  Elucidation of Primary (α3N) and Vestigial (α5) Heavy Metal-binding Sites in Staphylococcus aureus pI258 CadC: Evolutionary Implications for Metal Ion Selectivity of ArsR/SmtB Metal Sensor Proteins , 2002 .

[4]  M Mergeay,et al.  luxAB gene fusions with the arsenic and cadmium resistance operons of Staphylococcus aureus plasmid pI258. , 1993, FEMS microbiology letters.

[5]  M Virta,et al.  Detection of organomercurials with sensor bacteria. , 2001, Analytical chemistry.

[6]  J. Leveau,et al.  Improved gfp and inaZ broad-host-range promoter-probe vectors. , 2000, Molecular plant-microbe interactions : MPMI.

[7]  Z. Tynecka,et al.  Energy-dependent efflux of cadmium coded by a plasmid resistance determinant in Staphylococcus aureus , 1981, Journal of bacteriology.

[8]  M. Chalfie,et al.  Green fluorescent protein as a marker for gene expression. , 1994, Science.

[9]  S. Silver,et al.  Regulation of the cadA cadmium resistance determinant of Staphylococcus aureus plasmid pI258 , 1991, Journal of bacteriology.

[10]  M Virta,et al.  Luminescent bacterial sensor for cadmium and lead. , 1998, Biosensors & bioelectronics.

[11]  J Rishpon,et al.  Online and in situ monitoring of environmental pollutants: electrochemical biosensing of cadmium. , 2000, Environmental microbiology.

[12]  V. H. Liao,et al.  Development and testing of a green fluorescent protein‐based bacterial biosensor for measuring bioavailable arsenic in contaminated groundwater samples , 2005, Environmental toxicology and chemistry.

[13]  P. Vanhala,et al.  Soil respiration, ATP content, and Photobacterium toxicity test as indicators of metal pollution in soil , 1994 .

[14]  Sylvia Daunert,et al.  Luminescence-based whole-cell-sensing systems for cadmium and lead using genetically engineered bacteria , 2003, Analytical and bioanalytical chemistry.

[15]  G. Nucifora,et al.  Cadmium resistance from Staphylococcus aureus plasmid pI258 cadA gene results from a cadmium-efflux ATPase. , 1989, Proceedings of the National Academy of Sciences of the United States of America.

[16]  M. Dollard,et al.  Assessment of heavy metal bioavailability using Escherichia colizntAp::lux and copAp::lux-based biosensors , 2001, Applied Microbiology and Biotechnology.