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Malekzadeh, F; Farazmand, Abbas; Ghafourian, Hossein; Shahamat, M.; Levin, M. A.; Colwell, R. R.

doi:10.1023/a:1015215718810

Cited by 46 publications

(9 citation statements)

References 26 publications

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“…Above this pH, nickel started to precipitate. This work is in agreement with another worker 20. This may be due to the fact that metal biosorption depends on the protonation or deprotonation of the functional groups on the cell wall 3.…”

Section: Discussionsupporting

confidence: 92%

Biosorption of nickel (II) from effluent of electroplating industry by immobilized cells of Bacillus species

Tahir

Shehzadi

Mateen

et al. 2009

Engineering in Life Sciences

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In this study, Ni (II) biosorption capacity of immobilized cells of Bacillus sp. was investigated. Biosorption of Ni (II) was carried out in batch experiments and the important environmental conditions were optimized. The uptake of metal was rapid, and equilibrium was attained within 270 min. Bacillus strains (ten cultures) were isolated from nickel electroplating effluent by heat shock method. These isolates were grown up in nutrient broth supplemented with Ni (II)(50 mg/L). The culture, exhibiting maximum biosorption capacity (qmax: 118 mg/g), was selected and labeled Bacillus Bio‐4. In order to develop an economical biosorption process cell mass of Bacillus, Bio‐4 was immobilized in Na‐alginate. It was concluded from the results that biosorption of nickel is highly dependent on the type of sorbent and experimental conditions employed. Our results demonstrate that 6.0 mg immobilized cells (18 mg cell biomass in 3.0 mL of 1% Na alginate) had a maximum biosorption capacity of 113 mg Ni(II) per liter of suspension at pH 8.0, 100 rpm and 25°C. The Ni (II) removal was estimated to be 97.4%.

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Section: Discussionsupporting

confidence: 92%

Biosorption of nickel (II) from effluent of electroplating industry by immobilized cells of Bacillus species

Tahir

Shehzadi

Mateen

et al. 2009

Engineering in Life Sciences

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“…They accumulate HM from the environment as a result of the negative net charge of their cell envelope through a metabolism-independent passive or a metabolism-dependent active process that is determined by absorptivity of the cell envelope and ability to take up HM into the cytosol [106]. This metal accumulating ability can be utilized to remove, concentrate and recover HM from industrial effluents and mine tailings [107]. In mine tailings, the redox potential, physicochemical conditions, metal speciation and co-contaminants limit bacteria-metal interactions and bacterial activity.…”

Section: Bacterial Interaction With Heavy Metalsmentioning

confidence: 99%

Heavy Metal Pollution from Gold Mines: Environmental Effects and Bacterial Strategies for Resistance

Fashola

Ngole‐Jeme

Babalola

2016

IJERPH

512

216

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Mining activities can lead to the generation of large quantities of heavy metal laden wastes which are released in an uncontrolled manner, causing widespread contamination of the ecosystem. Though some heavy metals classified as essential are important for normal life physiological processes, higher concentrations above stipulated levels have deleterious effects on human health and biota. Bacteria able to withstand high concentrations of these heavy metals are found in the environment as a result of various inherent biochemical, physiological, and/or genetic mechanisms. These mechanisms can serve as potential tools for bioremediation of heavy metal polluted sites. This review focuses on the effects of heavy metal wastes generated from gold mining activities on the environment and the various mechanisms used by bacteria to counteract the effect of these heavy metals in their immediate environment.

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“…ioremediation strategies, such as bioreduction (1-3), biosorption (4)(5)(6)(7)(8), bioaccumulation (9,10), and bioprecipitation (5,11,12,13), have been studied for their potential to immobilize U from solutions. There is also a large body of work on microbial interactions with uranium relevant to environmental in situ bioremediation.…”

mentioning

confidence: 99%

Interaction of Uranium with Bacterial Cell Surfaces: Inferences from Phosphatase-Mediated Uranium Precipitation

Kulkarni

Misra

Gupta

et al. 2016

Appl Environ Microbiol

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Deinococcus radiodurans and Escherichia coli expressing either PhoN, a periplasmic acid phosphatase, or PhoK, an extracellular alkaline phosphatase, were evaluated for uranium (U) bioprecipitation under two specific geochemical conditions (GCs): (i) a carbonate-deficient condition at near-neutral pH (GC1), and (ii) a carbonate-abundant condition at alkaline pH (GC2). Transmission electron microscopy revealed that recombinant cells expressing PhoN/PhoK formed cell-associated uranyl phosphate precipitate under GC1, whereas the same cells displayed extracellular precipitation under GC2. These results implied that the cell-bound or extracellular location of the precipitate was governed by the uranyl species prevalent at that particular GC, rather than the location of phosphatase. MINTEQ modeling predicted the formation of predominantly positively charged uranium hydroxide ions under GC1 and negatively charged uranyl carbonate-hydroxide complexes under GC2. Both microbes adsorbed 6-to 10-fold more U under GC1 than under GC2, suggesting that higher biosorption of U to the bacterial cell surface under GC1 may lead to cell-associated U precipitation. In contrast, at alkaline pH and in the presence of excess carbonate under GC2, poor biosorption of negatively charged uranyl carbonate complexes on the cell surface might have resulted in extracellular precipitation. The toxicity of U observed under GC1 being higher than that under GC2 could also be attributed to the preferential adsorption of U on cell surfaces under GC1. This work provides a vivid description of the interaction of U complexes with bacterial cells. The findings have implications for the toxicity of various U species and for developing biological aqueous effluent waste treatment strategies. IMPORTANCEThe present study provides illustrative insights into the interaction of uranium (U) complexes with recombinant bacterial cells overexpressing phosphatases. This work demonstrates the effects of aqueous speciation of U on the biosorption of U and the localization pattern of uranyl phosphate precipitated as a result of phosphatase action. Transmission electron microscopy revealed that location of uranyl phosphate (cell associated or extracellular) was primarily influenced by aqueous uranyl species present under the given geochemical conditions. The data would be useful for understanding the toxicity of U under different geochemical conditions. Since cell-associated precipitation of metal facilitates easy downstream processing by simple gravitybased settling down of metal-loaded cells, compared to cumbersome separation techniques, the results from this study are of considerable relevance to effluent treatment using such cells. Bioremediation strategies, such as bioreduction (1-3), biosorption (4-8), bioaccumulation (9, 10), and bioprecipitation (5, 11, 12, 13), have been studied for their potential to immobilize U from solutions. There is also a large body of work on microbial interactions with uranium relevant to environmental in situ bioremediation. The...

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Cited by 46 publications

References 26 publications

Biosorption of nickel (II) from effluent of electroplating industry by immobilized cells of Bacillus species

Biosorption of nickel (II) from effluent of electroplating industry by immobilized cells of Bacillus species

Heavy Metal Pollution from Gold Mines: Environmental Effects and Bacterial Strategies for Resistance

Interaction of Uranium with Bacterial Cell Surfaces: Inferences from Phosphatase-Mediated Uranium Precipitation

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