Heavy Metal Toxicity Testing in Environmental Samples

Kong, In Chul; Bitton, Gabriel; Koopman, Ben; Jung, Keumhee

doi:10.1007/978-1-4612-4252-9_5

Cited by 54 publications

(32 citation statements)

References 118 publications

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“…One important application for transcriptional control of genes in response to extracellular metals is the construction of cellbased biosensors for the detection of metals in the environment (62). To date, cell-based biosensors have taken advantage of naturally occurring receptors or transcription factors that bind a metal of interest, combined with the fusion of a reporter gene to a promoter controlled by the corresponding downstream signaling pathway (9).…”

Section: Resultsmentioning

confidence: 99%

Computational design of a Zn²⁺receptor that controls bacterial gene expression

Dwyer

Looger

Hellinga

2003

Proc. Natl. Acad. Sci. U.S.A.

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The control of cellular physiology and gene expression in response to extracellular signals is a basic property of living systems. We have constructed a synthetic bacterial signal transduction pathway in which gene expression is controlled by extracellular Zn 2؉ . In this system a computationally designed Zn 2؉ -binding periplasmic receptor senses the extracellular solute and triggers a two-component signal transduction pathway via a chimeric transmembrane protein, resulting in transcriptional up-regulation of a ␤-galactosidase reporter gene. The Zn 2؉ -binding site in the designed receptor is based on a four-coordinate, tetrahedral primary coordination sphere consisting of histidines and glutamates. In addition, mutations were introduced in a secondary coordination sphere to satisfy the residual hydrogen-bonding potential of the histidines coordinated to the metal. The importance of the secondary shell interactions is demonstrated by their effect on metal affinity and selectivity, as well as protein stability. Three designed protein sequences, comprising two distinct metal-binding positions, were all shown to bind Zn 2؉ and to function in the cell-based assay, indicating the generality of the design methodology. These experiments demonstrate that biological systems can be manipulated with computationally designed proteins that have drastically altered ligand-binding specificities, thereby extending the repertoire of genetic control by extracellular signals.

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Section: Resultsmentioning

confidence: 99%

Computational design of a Zn²⁺receptor that controls bacterial gene expression

Dwyer

Looger

Hellinga

2003

Proc. Natl. Acad. Sci. U.S.A.

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“…Microtox results that are precise have been obtained for xenobiotics in extracts from soils, sludges, and sediments (Bitton and Koopman, 1992;Kong et al, 1995;Karuppiah et al, 1997;Sunahara et al, 1998Sunahara et al, , 1999Cassells et al, 2000;Cook et al, 2000).…”

Section: Discussionmentioning

confidence: 91%

“…Much recent work has occurred with the new Microtox solid-state bioassay (Bitton and Koopman, 1992;Kong et al, 1995;Ronnpagel et al, 1995;Kwan and Dutka, 1995;Wendt et al, 1996;Cheung et al, 1997;Harkey and Pradhan, 1998;Lee et al, 1999;Dorn and Salanitro, 2000), although the modi"ed test still appears to lack sensitivity for xenobiotics in soils, sludges, and sediments. Microtox results that are precise have been obtained for xenobiotics in extracts from soils, sludges, and sediments (Bitton and Koopman, 1992;Kong et al, 1995;Karuppiah et al, 1997;Sunahara et al, 1998Sunahara et al, , 1999Cassells et al, 2000;Cook et al, 2000).…”

Section: Discussionmentioning

confidence: 99%

“…In the United States, it is involved in American Society for Testing and Materials (ASTM) Method D-5660 (ASTM, 1996), and in the Standard Methods for the Examination of =ater and =astewater as Part 8050 (Clesceri et al, 1998a). It is sensitive to heavy metals, organics, and their mixtures (Kaiser and Devillers, 1994;Kong et al, 1995). The original test is supplemented by chronic, genotoxic, and acute solid-phase bioassays, using the same instrumentation (Azur Environmental, 2000;Strategic Diagnostics Inc., 2001).…”

Section: Introductionmentioning

confidence: 99%

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Effect of Dust on the Viability of Vibrio fischeri in the Microtox Test

Park

Hee

2001

Ecotoxicology and Environmental Safety

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“…The usefulness of hydrogen peroxide as a means of enhancing flotation was tested. The use of two-stage precipitation permitted the reduction in heavy metals (Cd, Cu, Cr, Ni, Sn, Zn), eg by applying ALCAT 102 -lime milk at the level exceeding 80%.Keywords: wastewaters containing heavy metals, wastewater treatment, chemical precipitation, flotation Considering widely documented toxicity, heavy metals belong to a category of troublesome components existing in the amounts of typical anthropogenic pollutants discharged with industrial sewage [1,2]. Difficulty in pretreating and treating such wastewaters is usually connected with the level of concentrations and speciation forms of metals in wastewaters [3][4][5][6].…”

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confidence: 99%

Treatment of the Processing Wastewaters Containing Heavy Metals with the Method Based on Flotation

Żak

2012

Ecological Chemistry and Engineering S

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Abstract:The aim of the studies carried out at full technological scale was to indicate optimal systems of the two-stage precipitation and coagulation (PIX 113 -SAX 18, PAX XL1 -SAX 18, ALCAT 102 -lime milk and SAX 18 -PAX 16) in the process of eliminating heavy metals from wastewaters made in the processing plant producing sub-systems for domestic appliances. Precipitated pollutions were thickened by flocculation and separated by hydrogen peroxide enhanced pressure flotation. The experimental installation of maximal flow capacity: 10.0 m 3 /d consisted of: the storage-equalization tank, the processing pipe reactor, the pressure flotation station, and the reagent preparation and dosing station. Optimal doses of reagents and a flocculent as well as pressure and saturation time were defined for which maximal reductions in the load of heavy metals were achieved. The usefulness of hydrogen peroxide as a means of enhancing flotation was tested. The use of two-stage precipitation permitted the reduction in heavy metals (Cd, Cu, Cr, Ni, Sn, Zn), eg by applying ALCAT 102 -lime milk at the level exceeding 80%.Keywords: wastewaters containing heavy metals, wastewater treatment, chemical precipitation, flotation Considering widely documented toxicity, heavy metals belong to a category of troublesome components existing in the amounts of typical anthropogenic pollutants discharged with industrial sewage [1,2]. Difficulty in pretreating and treating such wastewaters is usually connected with the level of concentrations and speciation forms of metals in wastewaters [3][4][5][6]. Several processes using different physico-chemical or mechanical methods of treatment of metal parts are related with the use of water and producing industrial effluents [7][8][9]. The load of heavy metals in such sewages reaches different levels of concentration and is mostly affected by the processes of covering, detox bath residues, cleaning metal surfaces or washing production areas [7,8,10]. In processing effluents, heavy metals are found in different physicochemical forms: ionic, ionic-coordinative, emulsive (eg water-oily and suspensive) [3,8,9]. The treatment of such wastewaters is practically conducted by using different physicochemical methods [3,8,9,11]. The stage of basic, chemical treatment is mostly preceded by applying the systems of

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Heavy Metal Toxicity Testing in Environmental Samples

Cited by 54 publications

References 118 publications

Computational design of a Zn²⁺receptor that controls bacterial gene expression

Computational design of a Zn²⁺receptor that controls bacterial gene expression

Effect of Dust on the Viability of Vibrio fischeri in the Microtox Test

Treatment of the Processing Wastewaters Containing Heavy Metals with the Method Based on Flotation

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Heavy Metal Toxicity Testing in Environmental Samples

Cited by 54 publications

References 118 publications

Computational design of a Zn2+receptor that controls bacterial gene expression

Computational design of a Zn2+receptor that controls bacterial gene expression

Effect of Dust on the Viability of Vibrio fischeri in the Microtox Test

Treatment of the Processing Wastewaters Containing Heavy Metals with the Method Based on Flotation

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Computational design of a Zn²⁺receptor that controls bacterial gene expression

Computational design of a Zn²⁺receptor that controls bacterial gene expression