Online and in situ monitoring of environmental pollutants: electrochemical biosensing of cadmium.
Online sensitive monitoring of gene expression is essential for understanding microbial life and microbial communities, especially under stress-inducing conditions, such as the presence of environmental pollutants. We describe here a novel use of promoter-based electrochemical biosensing for online and in situ monitoring of gene expression in response to pollutants. As a model system, we used a cadmium-responsive promoter from Escherichia coil fused to a promoterless lacZ gene, which was monitored using an electrochemical assay of beta-galactosidase activity. This whole-cell biosensor could detect, within minutes, nanomolar concentrations of cadmium in water, sea water and soil samples, and it can be used for continuous online and in situ monitoring.
Biran
I
I
Department of Molecular Microbiology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Israel.
Babai
R
R
Levcov
K
K
Rishpon
J
J
Ron
E Z
EZ
D000251:Adenosine Triphosphatases; D015374:Biosensing Techniques; D002104:Cadmium / Q000032:analysis*; D004563:Electrochemistry; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D017930:Genes, Reporter / Q000235:genetics; D007763:Lac Operon / Q000235:genetics; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000096:biosynthesis; D012623:Seawater / Q000382:microbiology; D012988:Soil Microbiology; D001616:beta-Galactosidase / Q000096:biosynthesis
D004785:Environmental Pollutants; D011994:Recombinant Proteins; D002104:Cadmium; D001616:beta-Galactosidase; D000251:Adenosine Triphosphatases; C109898:Zn(II)-translocating P-type ATPase