Methylation: Its role in the environmental mobility of heavy elements

Thayer, John S.

doi:10.1002/aoc.590030202

Cited by 36 publications

(13 citation statements)

References 12 publications

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“…7,13 Abiotic methylation of selenium, leading to volatile species, may also occur from inorganic selenide-metal cation (M-Se) complexes in the presence of strong carbo-cation donors such as halomethane (CH 3 -X) or sulphonium compounds ((CH 3 )S -R 2 ). 15 The presence of these methylating agents is indicated in productive waters, and favours this hypothesis. 16 The volatile methylated selenium species may then represent the 'end products' of selenium speciation reactions in the aquatic environment, due to their good stability with respect to oxidation and hydrolysis.…”

Section: Introductionmentioning

confidence: 79%

Formation of volatile selenium species in synthetic seawater under light and dark experimental conditions

Amouroux

Pécheyran

Donard

2000

Appl. Organometal. Chem.

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Experiments were performed in the laboratory on synthetic seawater spiked with different selenium species at trace levels to study the formation of volatile selenium compounds under dark or controlled simulated sunlight conditions. Spiking the reaction media with inorganic and organic selenium compounds demonstrated that several volatile selenium species could be formed under these simulated conditions. Selenoamino acids react to produce significant amounts of volatile selenium species in both light and dark conditions. Products formed include dimethyl selenide (DMSe), dimethyl selenyl sulphide (DMSeS) and dimethyl diselenide (DMDSe). Inorganic selenium oxyanions added to the synthetic reaction media did not form volatile species via abiotic reactions despite the presence of strong methylating agents. These results suggest that the formation of stable volatile species from bio‐organic selenium compounds can occur via abiotic reactions in the marine photic zone. Copyright © 2000 John Wiley & Sons, Ltd.

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Section: Introductionmentioning

confidence: 79%

Formation of volatile selenium species in synthetic seawater under light and dark experimental conditions

Amouroux

Pécheyran

Donard

2000

Appl. Organometal. Chem.

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“…Methylated derivatives of several elements naturally arise in the environment as a result of chemical and biological methylation, microbes playing significant roles in the latter process (Thayer, 1989;Gadd, 1993b , by some bacteria. Phenylmercury can also be microbially converted to diphenylmercury (Barkay & Wagner-Dobler, 2005).…”

Section: Metal Mobilizationmentioning

confidence: 99%

Metals, minerals and microbes: geomicrobiology and bioremediation

2010

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Microbes play key geoactive roles in the biosphere, particularly in the areas of element biotransformations and biogeochemical cycling, metal and mineral transformations, decomposition, bioweathering, and soil and sediment formation. All kinds of microbes, including prokaryotes and eukaryotes and their symbiotic associations with each other and 'higher organisms', can contribute actively to geological phenomena, and central to many such geomicrobial processes are transformations of metals and minerals. Microbes have a variety of properties that can effect changes in metal speciation, toxicity and mobility, as well as mineral formation or mineral dissolution or deterioration. Such mechanisms are important components of natural biogeochemical cycles for metals as well as associated elements in biomass, soil, rocks and minerals, e.g. sulfur and phosphorus, and metalloids, actinides and metal radionuclides. Apart from being important in natural biosphere processes, metal and mineral transformations can have beneficial or detrimental consequences in a human context. Bioremediation is the application of biological systems to the clean-up of organic and inorganic pollution, with bacteria and fungi being the most important organisms for reclamation, immobilization or detoxification of metallic and radionuclide pollutants. Some biominerals or metallic elements deposited by microbes have catalytic and other properties in nanoparticle, crystalline or colloidal forms, and these are relevant to the development of novel biomaterials for technological and antimicrobial purposes. On the negative side, metal and mineral transformations by microbes may result in spoilage and destruction of natural and synthetic materials, rock and mineral-based building materials (e.g. concrete), acid mine drainage and associated metal pollution, biocorrosion of metals, alloys and related substances, and adverse effects on radionuclide speciation, mobility and containment, all with immense social and economic consequences. The ubiquity and importance of microbes in biosphere processes make geomicrobiology one of the most important concepts within microbiology, and one requiring an interdisciplinary approach to define environmental and applied significance and underpin exploitation in biotechnology. Microbes as geoactive agentsMicrobes interact with metals and minerals in natural and synthetic environments, altering their physical and chemical state, with metals and minerals also able to affect microbial growth, activity and survival. In addition, many minerals are biogenic in origin, and the formation of such biominerals is of global geological and industrial significance, as well as providing important structural components for many organisms, including important microbial groups such as diatoms, foraminifera and radiolaria (Ehrlich, 1996;Gadd & Raven, 2010). Geomicrobiology can simply be defined as the roles of microbes in geological processes (Banfield & Nealson, 1997;Banfield et al., 2005; Konhauser, 2007;Ehrlich & Newman, 2009). Metalminera...

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“…The pathway of the formation of organometallic and organometalloid compounds has been comprehensively reviewed 25,35,194 . For example, selenium biomethylation led to the production of dimethylselenide, dimethyldiselenide, and dimethylselenone products in the soil and in sediments 195 . The remediation of selenium in soils and water is being thoroughly studied 196,197 .…”

Section: Mercury Resistance Encoded By Mer Operon Genesmentioning

confidence: 99%

Bioremediation of Heavy Metal Pollution Exploiting Constituents, Metabolites and Metabolic Pathways of Livings. A Review

Kotrba

Ruml

2000

Collect. Czech. Chem. Commun.

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Removal of heavy metals from the soil and water or their remediation from the waste streams "at source" has been a long-term challenge. During the recent era of environmental protection, the use of microorganisms for the recovery of metals from waste streams as well as employment of plants for landfill applications has generated growing attention. Many studies have demonstrated that both prokaryotes and eukaryotes have the ability to remove metals from contaminated water or waste streams. They sequester metals from soils and sediments or solubilize them to aid their extraction. The proposed microbial processes for bioremediation of toxic metals and radionuclides from waste streams employ living cells and non-living biomass or biopolymers as biosorbents. Microbial biotransformation of metals or metalloids results in an alteration of their oxidation state or in their alkylation and subsequent precipitation or volatilization. Specific metabolic pathways leading to precipitation of heavy metals as metal sulfides, phosphates or carbonates possess significance for possible biotechnology application. Moreover, the possibility of altering the properties of living species used in heavy metal remediation or constructing chimeric organisms possessing desirable features using genetic engineering is now under study in many laboratories. The encouraging evidence as to the usefulness of living organisms and their constituents as well as metabolic pathways for the remediation of metal contamination is reviewed here. A review with 243 references.

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Methylation: Its role in the environmental mobility of heavy elements

Cited by 36 publications

References 12 publications

Formation of volatile selenium species in synthetic seawater under light and dark experimental conditions

Formation of volatile selenium species in synthetic seawater under light and dark experimental conditions

Metals, minerals and microbes: geomicrobiology and bioremediation

Bioremediation of Heavy Metal Pollution Exploiting Constituents, Metabolites and Metabolic Pathways of Livings. A Review

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