In this study, we report the first ever large-scale environmental validation of a microbial reporter-based test to measure arsenic concentrations in natural water resources. A bioluminescence-producing arsenic-inducible bacterium based on Escherichia coli was used as the reporter organism. Specific protocols were developed with the goal to avoid the negative influence of iron in groundwater on arsenic availability to the bioreporter cells. A total of 194 groundwater samples were collected in the Red River and Mekong River Delta regions of Vietnam and were analyzed both by atomic absorption spectroscopy (AAS) and by the arsenic bioreporter protocol. The bacterial cells performed well at and above arsenic concentrations in groundwater of 7 μg/L, with an almost linearly proportional increase of the bioluminescence signal between 10 and 100 μg As/L (r² = 0.997). Comparisons between AAS and arsenic bioreporter determinations gave an overall average of 8.0% false negative and 2.4% false positive identifications for the bioreporter prediction at the WHO recommended acceptable arsenic concentration of 10 μg/L, which is far better than the performance of chemical field test kits. Because of the ease of the measurement protocol and the low application cost, the microbiological arsenic test has a great potential in large screening campaigns in Asia and in other areas suffering from arsenic pollution in groundwater resources. © 2005 American Chemical Society.

Trang P.T.K., Berg M., Viet P.H., Van Mui N., Van Der Meer J.R.

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Từ khóa : Absorption spectroscopy; Atomic spectroscopy; Bioassay; Bioluminescence; Cells; Escherichia coli; Groundwater resources; Signal processing; Water pollution; Bacterial bioassays; Bacterial cells; Bioreporter cells; Arsenic; arsenic; ground water; iron; fresh water; luciferase; arsenic; bioassay; groundwater pollution; microorganism; accuracy; analytical error; article; atomic absorption spectrometry; bacterial cell; bioassay; bioluminescence; biotechnology; cost; Escherichia coli; microbiological arsenic test; nonhuman; performance; prediction and forecasting; screening; signal detection; validation process; Viet Nam; water analysis; water contamination; water pollutant; water pollution; water pollution indicator; water sampling; water supply; world health organization; chemistry; comparative study; drug effect; environmental monitoring; metabolism; methodology; statistics; Bacteria (microorganisms); Escherichia coli; Arsenic; Environmental Monitoring; Escherichia coli; Fresh Water; Luciferases; Spectrophotometry, Atomic; Vietnam; Water Pollutants, Chemical