Environmental Chemistry of Arsenic

Frankenberger, W. T.

doi:10.1201/9781482271102

Cited by 106 publications

(37 citation statements)

References 42 publications

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“…The demethylation enzymes (and their genes) are also unidentified, while such a cycle must occur for completion of the cycle [72]. However, microbial methylation of inorganic arsenic has been recognized for over a century, as poisonous volatile arsenic compounds were released from ''moldy wall paper'' [39,72]. Similar methylation by prokaryotes and animal tissues has come more recently [72,109].…”

Section: Arsenic Enzymatic Redox Reactions and Resistancementioning

confidence: 98%

“…5) requires also the reduced small cytoplasmic protein reduced thioredoxin, the same cofactor as required by one group of intracellular arsenic reductases [69,72]. The mammalian enzyme in vitro produces mostly dimethylarsinic acid, very little of the monomethyl product and no detectible trimethylarsine oxide or reduced dimethylarsine and trimethylarsine (the volatile compounds, whose production can be considered a microbial resistance mechanism [39]). Clearly the availability of this first arsenic methylase gene and purified enzyme, although from mammalian sources, opens the possibility of rapid progress in genetic and structural biochemical study of these important transformations.…”

Section: Arsenic Enzymatic Redox Reactions and Resistancementioning

confidence: 99%

“…That is the methylation and demethylation of inorganic arsenic and the incorporation of inorganic arsenic in to small organic compounds such as arsenobetaine, arsenolipids and arsenosugars [39,72]. Little is known about the synthesis of the more complex organoarsenical compounds and this may be limited to eukaryotic organisms.…”

Section: Arsenic Enzymatic Redox Reactions and Resistancementioning

confidence: 99%

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A bacterial view of the periodic table: genes and proteins for toxic inorganic ions

Silver

Phung

2005

J IND MICROBIOL BIOTECHNOL

425

287

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Essentially all bacteria have genes for toxic metal ion resistances and these include those for Ag+, AsO2-, AsO4(3-), Cd2+ Co2+, CrO4(2-), Cu2+, Hg2+, Ni2+, Pb2+, TeO3(2-), Tl+ and Zn2+. The largest group of resistance systems functions by energy-dependent efflux of toxic ions. Fewer involve enzymatic transformations (oxidation, reduction, methylation, and demethylation) or metal-binding proteins (for example, metallothionein SmtA, chaperone CopZ and periplasmic silver binding protein SilE). Some of the efflux resistance systems are ATPases and others are chemiosmotic ion/proton exchangers. For example, Cd2+-efflux pumps of bacteria are either inner membrane P-type ATPases or three polypeptide RND chemiosmotic complexes consisting of an inner membrane pump, a periplasmic-bridging protein and an outer membrane channel. In addition to the best studied three-polypeptide chemiosmotic system, Czc (Cd2+, Zn2+, and Co2), others are known that efflux Ag+, Cu+, Ni2+, and Zn2+. Resistance to inorganic mercury, Hg2+ (and to organomercurials, such as CH3Hg+ and phenylmercury) involve a series of metal-binding and membrane transport proteins as well as the enzymes mercuric reductase and organomercurial lyase, which overall convert more toxic to less toxic forms. Arsenic resistance and metabolizing systems occur in three patterns, the widely-found ars operon that is present in most bacterial genomes and many plasmids, the more recently recognized arr genes for the periplasmic arsenate reductase that functions in anaerobic respiration as a terminal electron acceptor, and the aso genes for the periplasmic arsenite oxidase that functions as an initial electron donor in aerobic resistance to arsenite.

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Section: Arsenic Enzymatic Redox Reactions and Resistancementioning

confidence: 98%

Section: Arsenic Enzymatic Redox Reactions and Resistancementioning

confidence: 99%

Section: Arsenic Enzymatic Redox Reactions and Resistancementioning

confidence: 99%

See 1 more Smart Citation

A bacterial view of the periodic table: genes and proteins for toxic inorganic ions

Silver

Phung

2005

J IND MICROBIOL BIOTECHNOL

425

287

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“…The effect of P i on the sorption/desorption of As in soil environments has received attention. A number of studies have shown that arsenate may be partially removed from soil colloids by P i , but even large amounts of P i cannot desorb all the applied arsenate (Smith et al 1998;Frankenberger 2002;Violante and Pigna, 2002). Plant uptake of As has been shown to increase upon P application in pot experiments (Jiang and Singh, 1994) and at field scale (Small and McCants 1962).…”

Section: Introductionmentioning

confidence: 97%

Influence of Phosphate on the Arsenic Uptake by Wheat (Triticum durum L.) Irrigated with Arsenic Solutions at Three Different Concentrations

Pigna

Cozzolino

Violante

et al. 2008

Water Air Soil Pollut

105

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In this study we have investigated the uptake and distribution of arsenic (As) and phosphate (P i ) in roots, shoots, and grain of wheat grown in an uncontaminated soil irrigated with solutions containing As at three different concentrations (0.5, 1 and 2 mg l −1 ) and in the presence or in the absence of P fertilization. Arsenic in irrigation water reduced plants growth and decreased grain yield. When P i was not added (P−), plants were more greatly impacted compared to the plus P i (P+) treatments. The differences in mean biomass between P− and P+ treatments at the higher As concentrations demonstrated the role of P i in preventing As toxicity and growth inhibition. Arsenic concentrations in root, shoot and grain increased with increasing As concentration in irrigation water. It appears that P fertilization minimizes the translocation of As to the shoots and grain whilst enhancing P status of plant. The observation that P fertilization minimises the translocation of arsenic to the shoots and grain is interesting and may be useful for certain regions of the world that has high levels of As in groundwater or soils.

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“…For inorganic compounds of As, the acute and subacute effects of short/medium terms of exposure depend on the oxidation state (trivalent form is more toxic than pentavalent form) and solubility (sodium arsenate is ten times more toxic than trivalent As); however, human data on the differences in toxicity between As(III) and As(V) are still limited [3]. The non-carcinogenic effects of long-term exposure are mainly changes to the respiratory system and skin and are related to high levels of airborne inorganic As as a result of occupational exposure in specific industries (smelting, pesticide manufacturing) [4].…”

Section: Introductionmentioning

confidence: 99%

Determination of As in environmental solid matrix

2002

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In line with recent European environmental guidelines on biomasses, one of the most important parameters to take into account is the As concentration, especially when present in biomasses and complex matrices. The goal of the present study is to give information about possible technical-analytical problems during the determinations of such elements by means of different instrumental spectroscopy techniques, in particular inductively coupled plasma atomic emission (ICP-AES) and atomic absorption (AAS), using two different wavelengths, 188.98 nm and 193.70 nm. In the Laboratory of Hygiene of National Institute of Health in Italy, a specific study has been carried out concerning the determination of As contents in environmental solid matrices, using as reference material BCR 141 R, represented by a calcareous soil. In particular, whereas recovery tests did not show particular drawbacks, difficulties were met in the As detection in reference material. Spectral interference was seen during determination by ICP-AES and matrix interference during determination by AAS, in particular using ETAAS with deuterium background correction and HAAS. Using ETAAS with Zeeman background correction at 193.70 nm, the As line did not show particular matrix interference during the reading of samples.A ring test involving two more laboratories and another certified reference material (IAEA-356 in marine sediment matrix) produced important information about problems of under/over estimation of data. Two different instrumental techniques, ICP-MS and HAAS, confirmed previous data, i.e., overestimation for inductively coupled plasma mass spectrometry and that As values achieved by HAAS were of the same order as the references, but affected by considerable standard deviation. In the light of this study, data achieved on the environmental matrices investigated suggest that the critical step in As determination is the instrumental reading, rather than the mineralization process. Further, each of the methods proposed, apart from ETAAS with Zeeman background correction, presents its own peculiar drawbacks and no particular advantage over other techniques.

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Environmental Chemistry of Arsenic

Cited by 106 publications

References 42 publications

A bacterial view of the periodic table: genes and proteins for toxic inorganic ions

A bacterial view of the periodic table: genes and proteins for toxic inorganic ions

Influence of Phosphate on the Arsenic Uptake by Wheat (Triticum durum L.) Irrigated with Arsenic Solutions at Three Different Concentrations

Determination of As in environmental solid matrix

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