Development of a set of simple bacterial biosensors for quantitative and rapid measurements of arsenite and arsenate in potable water.
Details
Serval ID
serval:BIB_4D9CF0E4323C
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Development of a set of simple bacterial biosensors for quantitative and rapid measurements of arsenite and arsenate in potable water.
Journal
Environmental Science and Technology
ISSN
0013-936X (Print)
ISSN-L
0013-936X
Publication state
Published
Issued date
2003
Volume
37
Number
20
Pages
4743-4750
Language
english
Abstract
Testing for arsenic pollution is commonly performed with chemical test kits of unsatisfying accuracy. Bacterial biosensors are an interesting alternative as they are easily produced, simple, and highly accurate devices. Here, we describe the development of a set of bacterial biosensors based on a nonpathogenic laboratory strain of Escherichia coli, the natural resistance mechanism of E. coli against arsenite and arsenate, and three reporter proteins: bacterial luciferase, beta-galactosidase and Green Fluorescent Protein (GFP). The biosensors were genetically optimized to reduce background expression in the absence of arsenic. In calibration experiments with the biosensors and arsenite-amended potable water, arsenite concentrations at 4 microg of As/L (0.05 microM) were routinely and accurately measured. The currently most quantitative system expressed the bacterial luciferase as reporter protein, responding proportional with a concentration range between 8 and 80 microg of As/L. Sensor cells could be stored as frozen batches, resuspended in plain media, and exposed to the aqueous test sample, and light emission was measured after 30-min incubation. Field testing for arsenite was achieved with a system that contained beta-galactosidase, producing a visible blue color at arsenite concentrations above 8 microg/L. For this sensor, a protocol was developed in which the sensor cells were dried on a paper strip and placed in the aqueous test solution for 30 min after which time color development was allowed to take place. The GFP sensor showed good potential for continuous rather than end point measurements. In all cases, growth of the biosensors and production of the strip test was achieved by very simple means with common growth media, and quality control of the sensors was performed by isolating the respective plasmids with the genetic constructs according to simple standard genetic technologies. Therefore, the biosensor cells and protocols may offer a realistic alternative for measuring arsenic contamination in potable water.
Keywords
Arsenates/analysis, Arsenites/analysis, Biosensing Techniques/methods, Environmental Monitoring/methods, Escherichia coli/physiology, Gene Expression Regulation, Green Fluorescent Proteins, Luciferases/analysis, Luciferases/biosynthesis, Luminescent Proteins/analysis, Luminescent Proteins/biosynthesis, Reproducibility of Results, Water Pollutants/analysis, Water Supply, beta-Galactosidase/analysis, beta-Galactosidase/biosynthesis
Pubmed
Web of science
Create date
21/01/2008 14:36
Last modification date
20/08/2019 15:02