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Journal ArticleDOI

Metal - Microbes Interactions: beyond Environmental Protection

01 May 2009-Advanced Materials Research (Trans Tech Publications Ltd)-pp 527-532
TL;DR: Bioremediation can be applied for the treatment of metal/metalloid and radionuclide bearing water streams in order to immobilize the targeted species and bioprecipitation and bioreduction are the basis of technologies for the rehabilitation of contaminated sites.
Abstract: Bioremediation can be applied for the treatment of metal/metalloid and radionuclide bearing water streams in order to immobilize the targeted species. Interactions of microbial cells with soluble targeted species may occur during the microbial metabolism and result to the reduction of their mobility and toxicity. The most important metabolically mediated immobilization processes for metal/metalloid and radionuclide species are bioprecipitation and bioreduction. Bioprecipitation includes the transformation of soluble species to insoluble hydroxides, carbonates, phosphates and sulfides as a result of the microbial metabolism. In the case of biological reduction, the cells use the species as terminal electron acceptors in anoxic environments to produce energy and/or reduce the toxicity of the cells microenvironment. These processes can be the basis of technologies for the rehabilitation of contaminated sites both for surface and groundwater aquifers, soils and industrial water streams. Such technologies are recently developed and applied both in pilot and full scale, although the related mechanisms are complicated and not always fully understood.
Citations
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Journal ArticleDOI
TL;DR: Consumption of vegetables grown on metal-contaminated soil were nutrient deficient and consumption of such vegetables may lead to nutritional deficiency in the population particularly living in developing countries which are already facing the malnutrition problems.
Abstract: Heavy metal contamination is a globally recognized environmental issue, threatening human life very seriously. Increasing population and high demand for food resulted in release of various contaminants into environment that finally contaminate the food chain. Edible plants are the major source of diet, and their contamination with toxic metals may result in catastrophic health hazards. Heavy metals affect the human health directly and/or indirectly; one of the indirect effects is the change in plant nutritional values. Previously, a number of review papers have been published on different aspects of heavy metal contamination. However, no related information is available about the effects of heavy metals on the nutritional status of food plants. This review paper is focused upon heavy metal sources, accumulation, transfer, health risk, and effects on protein, amino acids, carbohydrates, fats, and vitamins in plants. The literature about heavy metals in food plants shows that both leafy and nonleafy vegetables are good accumulators of heavy metals. In nonleafy vegetables, the bioaccumulation pattern was leaf > root ≈ stem > tuber. Heavy metals have strong influence on nutritional values; therefore, plants grown on metal-contaminated soil were nutrient deficient and consumption of such vegetables may lead to nutritional deficiency in the population particularly living in developing countries which are already facing the malnutrition problems.

546 citations


Cites background from "Metal - Microbes Interactions: beyo..."

  • ...Effects of high heavy metal concentrations on the microbial community structure, activity, and abundance have been reported (Khan et al. 2010b; Sandaa et al. 1999; Tsezos 2009)....

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Journal ArticleDOI
TL;DR: In this paper, the authors highlight the different mechanisms of metal resistance and plant growth promotion of metal resistant PGPB as well as the recent development in exploitation of these bacteria in bioremediation of heavy metals in different agroecosystems.

158 citations

Journal ArticleDOI
TL;DR: FISH analysis indicated that Actinobacteria and Proteobacteria represent the physiologically active fraction of bacteria at the two sites, and Shannon diversity (H') indices for FISH-detected bacterial phylogenetic groups were not significantly different at theTwo sites.

113 citations


Cites background from "Metal - Microbes Interactions: beyo..."

  • ...Long-term impacts of heavy metals on soil microorganisms result in adverse effects on microbial activities and abundance, and altered microbial community structures (Tsezos, 2009)....

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Journal ArticleDOI
TL;DR: A review of the existing literature on sediment remediation techniques and developments in the fields of environmental science and engineering, attempting to provide a better understanding of the advances of remedy techniques and new research directions for sediments contaminated by heavy metals is presented in this paper.
Abstract: Contamination of sediments with heavy metals (HMs) is a worldwide environmental issue, due to the negative ecological effects of HMs. Sediments are an important component of aquatic ecosystems, impacting the transformation and transfer of HMs in the environment. Thus, remediating sediments polluted by HMs is a crucial activity within the full aquatic ecosystem remediation process, and economical, effective, and environmentally friendly remediation techniques are urgently needed. We reviewed the existing literature on sediment remediation techniques and developments in the fields of environmental science and engineering, attempting to provide a better understanding of the advances of remediation techniques and new research directions for sediments contaminated by HMs. This review summarized remediation methods (e.g., physical–chemical strategies, biological strategies, and combined techniques) used to treat sediments contaminated with HMs. This included analyzing the mechanisms associated with biological remediation technologies and their combination with other methods. Then, the review summarized the factors influencing the selection of remediation methods and evaluated the prospects of new emerging remediation methods. Bioimmobilization techniques (e.g., phytostabilization and microorganism immobilization) have received increased attention because of their low remediation cost and environmental compatibility. Furthermore, particular attention has been paid to explore the role of sulfate-reducing bacteria in decreasing heavy metal mobility. The review provides a useful theoretical foundation and technology reference for the remediation of sediment polluted by HMs.

108 citations


Cites background from "Metal - Microbes Interactions: beyo..."

  • ...Bioprecipitation involves using microbial metabolism to transform soluble species to insoluble hydroxides, carbonates, phosphates, and sulfides (Tsezos 2009)....

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  • ..., Fe(II) and H2S) of metal-reducing microorganisms and SRB can also indirectly reduce Cr(VI), Tc(VII), and U(VI) (Tabak et al. 2005; Tsezos 2009; Ahemad 2014)....

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  • ...However, microbial remediation also has some disadvantages (Tsezos 2009; Mani and Kumar 2014; Akcil et al. 2015)....

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  • ...…and mobile Cr(VI), Tc(VII), and U(VI) into insoluble and immobile Cr(III), Tc(IV), and U(IV), respectively; the reduced products (e.g., Fe(II) and H2S) of metal-reducing microorganisms and SRB can also indirectly reduce Cr(VI), Tc(VII), and U(VI) (Tabak et al. 2005; Tsezos 2009; Ahemad 2014)....

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  • ...This reduces HM toxicity by forming complexes or by creating a useful barrier around the cell (Tsezos 2009; Ahemad 2014)....

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References
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Book
25 Jul 2000
TL;DR: This paper describes the development of biofilm Kinetics and its applications in water treatment, as well as some of the systems used for detoxification of Hazardous Chemicals.
Abstract: 1 Basics of Microbiology 2 Stoichiometry and Bacterial Energetics 3 Microbial Kinetics 4 Biofilm Kinetics 5 Reactors 6 Complex Systems 7 The Activated Sludge Process 8 Lagoons 9 Aerobic Biofilm Process 10 Nitrification 11 Denitrification 12 Phosphorus Removal 13 Drinking Water Treatment 14 Anaerobic Treatment by Methanogenesis 15 Detoxification of Hazardous Chemicals 16 Bioremediation

2,408 citations

Journal ArticleDOI
04 Aug 2000-Science
TL;DR: High-resolution transmission electron microscopy of biomineralization products of iron-oxidizing bacteria revealed an alternative coarsening mechanism in which adjacent 2- to 3-nanometer particles aggregate and rotate so their structures adopt parallel orientations in three dimensions.
Abstract: Crystals are generally considered to grow by attachment of ions to inorganic surfaces or organic templates. High-resolution transmission electron microscopy of biomineralization products of iron-oxidizing bacteria revealed an alternative coarsening mechanism in which adjacent 2- to 3-nanometer particles aggregate and rotate so their structures adopt parallel orientations in three dimensions. Crystal growth is accomplished by eliminating water molecules at interfaces and forming iron-oxygen bonds. Self-assembly occurs at multiple sites, leading to a coarser, polycrystalline material. Point defects (from surface-adsorbed impurities), dislocations, and slabs of structurally distinct material are created as a consequence of this growth mechanism and can dramatically impact subsequent reactivity.

1,620 citations

Journal ArticleDOI
TL;DR: This review focuses on the applicability of growing bacterial/fungal/algal cells for metal removal and the efforts directed towards cell/process development to make this option technically/economically viable for the comprehensive treatment of metal-rich effluents.

1,088 citations

Journal ArticleDOI
01 Oct 2004-Geoderma
TL;DR: This contribution will outline selected microbiological processes which are of significance in determining metal mobility and which have actual and potential application in bioremediation of metal pollution.

654 citations

Journal ArticleDOI
TL;DR: The results indicate that enzymatic U(VI) reduction by sulfate-reducing microorganisms may be responsible for the accumulation of U(IV) in sulfidogenic environments and D. desulfuricans might be a useful organism for recovering uranium from contaminated waters and waste streams.
Abstract: The possibility that sulfate-reducing microorganisms contribute to U(VI) reduction in sedimentary environments was investigated. U(VI) was reduced to U(IV) when washed cells of sulfate-grown Desulfovibrio desulfuricans were suspended in a bicarbonate buffer with lactate or H2 as the electron donor. There was no U(VI) reduction in the absence of an electron donor or when the cells were killed by heat prior to the incubation. The rates of U(VI) reduction were comparable to those in respiratory Fe(III)-reducing microorganisms. Azide or prior exposure of the cells to air did not affect the ability of D. desulfuricans to reduce U(VI). Attempts to grow D. desulfuricans with U(VI) as the electron acceptor were unsuccessful. U(VI) reduction resulted in the extracellular precipitation of the U(IV) mineral uraninite. The presence of sulfate had no effect on the rate of U(VI) reduction. Sulfate and U(VI) were reduced simultaneously. Enzymatic reduction of U(VI) by D. desulfuricans was much faster than nonenzymatic reduction of U(VI) by sulfide, even when cells of D. desulfuricans were added to provide a potential catalytic surface for the nonenzymatic reaction. The results indicate that enzymatic U(VI) reduction by sulfate-reducing microorganisms may be responsible for the accumulation of U(IV) in sulfidogenic environments. Furthermore, since the reduction of U(VI) to U(IV) precipitates uranium from solution, D. desulfuricans might be a useful organism for recovering uranium from contaminated waters and waste streams.

587 citations