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Malik S, Kumar D. Perspectives of nanomaterials in microbial remediation of heavy metals and their environmental consequences: A review. Biotechnol Genet Eng Rev 2023:1-48. [PMID: 36871166 DOI: 10.1080/02648725.2023.2182546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 02/06/2023] [Indexed: 03/06/2023]
Abstract
Nanomaterials (NMs) have diverse applications in various sectors, such as decontaminating heavy metals from drinking water, wastewater, and soil. Their degradation efficiency can be enhanced through the application of microbes. As microbial strain releases enzymes, which leads to the degradation of HMs. Therefore, nanotechnology and microbial-assisted remediation-based methods help us develop a remediation process with practical utility, speed, and less environmental toxicity. This review focuses on the success achieved for the bioremediation of heavy metals by nanoparticles and microbial strains and in their integrated approach. Still, the use of NMs and heavy metals (HMs) can negatively affect the health of living organisms. This review describes various aspects of the bioremediation of heavy materials using microbial nanotechnology. Their safe and specific use supported by bio-based technology paves the way for their better remediation. We discuss the utility of nanomaterials for removing heavy metals from wastewater, toxicity studies and issues to the environment with their practical implications. Nanomaterial assisted heavy metal degradation coupled with microbial technology and disposal issues are described along with detection methods. Environmental impact of nanomaterials is also discussed based on the recent work conducted by the researchers. Therefore, this review opens new avenues for future research with an impact on the environment and toxicity issues. Also, applying new biotechnological tools will help us develop better heavy metal degradation routes.
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Affiliation(s)
- Sachin Malik
- Department of Biotechnology, Deenbandhu Chhotu Ram University of Science and Technology, Sonepat, Haryana, India
| | - Dharmender Kumar
- Department of Biotechnology, Deenbandhu Chhotu Ram University of Science and Technology, Sonepat, Haryana, India
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Kumar Rai R, Shankar Pati R, Islam A, Roy G. Detoxification of organomercurials by thiones and selones: A short review. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2022.120980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Christakis CA, Barkay T, Boyd ES. Expanded Diversity and Phylogeny of mer Genes Broadens Mercury Resistance Paradigms and Reveals an Origin for MerA Among Thermophilic Archaea. Front Microbiol 2021; 12:682605. [PMID: 34248899 PMCID: PMC8261052 DOI: 10.3389/fmicb.2021.682605] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/28/2021] [Indexed: 11/13/2022] Open
Abstract
Mercury (Hg) is a highly toxic element due to its high affinity for protein sulfhydryl groups, which upon binding, can destabilize protein structure and decrease enzyme activity. Prokaryotes have evolved enzymatic mechanisms to detoxify inorganic Hg and organic Hg (e.g., MeHg) through the activities of mercuric reductase (MerA) and organomercury lyase (MerB), respectively. Here, the taxonomic distribution and evolution of MerAB was examined in 84,032 archaeal and bacterial genomes, metagenome assembled genomes, and single-cell genomes. Homologs of MerA and MerB were identified in 7.8 and 2.1% percent of genomes, respectively. MerA was identified in the genomes of 10 archaeal and 28 bacterial phyla previously unknown to code for this functionality. Likewise, MerB was identified in 2 archaeal and 11 bacterial phyla previously unknown to encode this functionality. Surprisingly, homologs of MerB were identified in a number of genomes (∼50% of all MerB-encoding genomes) that did not encode MerA, suggesting alternative mechanisms to detoxify Hg(II) once it is generated in the cytoplasm. Phylogenetic reconstruction of MerA place its origin in thermophilic Thermoprotei (Crenarchaeota), consistent with high levels of Hg(II) in geothermal environments, the natural habitat of this archaeal class. MerB appears to have been recruited to the mer operon relatively recently and likely among a mesophilic ancestor of Euryarchaeota and Thaumarchaeota. This is consistent with the functional dependence of MerB on MerA and the widespread distribution of mesophilic microorganisms that methylate Hg(II) at lower temperature. Collectively, these results expand the taxonomic and ecological distribution of mer-encoded functionalities, and suggest that selection for Hg(II) and MeHg detoxification is dependent not only on the availability and type of mercury compounds in the environment but also the physiological potential of the microbes who inhabit these environments. The expanded diversity and environmental distribution of MerAB identify new targets to prioritize for future research.
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Affiliation(s)
- Christos A. Christakis
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Tamar Barkay
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
| | - Eric S. Boyd
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
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Rahman Z, Singh VP. Bioremediation of toxic heavy metals (THMs) contaminated sites: concepts, applications and challenges. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:27563-27581. [PMID: 32418096 DOI: 10.1007/s11356-020-08903-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/15/2020] [Indexed: 06/11/2023]
Abstract
Heavy metal contamination is a global issue, where the prevalent contaminants are arsenic (As), cadmium (Cd), chromium (Cr)(VI), mercury (Hg), and lead (Pb). More often, they are collectively known as "most problematic heavy metals" and "toxic heavy metals" (THMs). Their treatment through a variety of biological processes is one of the prime interests in remediation studies, where heavy metal-microbe interaction approaches receive high interest for their cost effective and ecofriendly solutions. In this review, we provide an up to date information on different microbial processes (bioremediation) for the removal of THMs. For the same, emphasis is put on oxidation-reduction, biomineralization, bioprecipitation, bioleaching, biosurfactant technology, biovolatilization, biosorption, bioaccumulation, and microbe-assisted phytoremediation with their selective advantages and disadvantages. Further, the literature briefly discusses about the various setups of cleaning processes of THMs in environment under ex situ and in situ applications. Lately, the study sheds light on the manipulation of microorganisms through genetic engineering and nanotechnology for their advanced treatment approaches.
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Affiliation(s)
- Zeeshanur Rahman
- Department of Botany, Zakir Husain Delhi College, University of Delhi, Delhi, India.
- Department of Botany, University of Delhi, Delhi, India.
| | - Ved Pal Singh
- Department of Botany, University of Delhi, Delhi, India
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Martínez-Espinosa RM. Microorganisms and Their Metabolic Capabilities in the Context of the Biogeochemical Nitrogen Cycle at Extreme Environments. Int J Mol Sci 2020; 21:ijms21124228. [PMID: 32545812 PMCID: PMC7349289 DOI: 10.3390/ijms21124228] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 06/12/2020] [Indexed: 12/23/2022] Open
Abstract
Extreme microorganisms (extremophile) are organisms that inhabit environments characterized by inhospitable parameters for most live beings (extreme temperatures and pH values, high or low ionic strength, pressure, or scarcity of nutrients). To grow optimally under these conditions, extremophiles have evolved molecular adaptations affecting their physiology, metabolism, cell signaling, etc. Due to their peculiarities in terms of physiology and metabolism, they have become good models for (i) understanding the limits of life on Earth, (ii) exploring the possible existence of extraterrestrial life (Astrobiology), or (iii) to look for potential applications in biotechnology. Recent research has revealed that extremophilic microbes play key roles in all biogeochemical cycles on Earth. Nitrogen cycle (N-cycle) is one of the most important biogeochemical cycles in nature; thanks to it, nitrogen is converted into multiple chemical forms, which circulate among atmospheric, terrestrial and aquatic ecosystems. This review summarizes recent knowledge on the role of extreme microorganisms in the N-cycle in extremophilic ecosystems, with special emphasis on members of the Archaea domain. Potential implications of these microbes in global warming and nitrogen balance, as well as their biotechnological applications are also discussed.
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Affiliation(s)
- Rosa María Martínez-Espinosa
- Biochemistry and Molecular Biology Division, Agrochemistry and Biochemistry Department, Faculty of Sciences, University of Alicante, Ap. 99, E-03080 Alicante, Spain; ; Tel.: +34-965903400 (ext. 1258)
- Multidisciplinary Institute for Environmental Studies “Ramón Margalef”, University of Alicante, Ap. 99, E-03080 Alicante, Spain
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Superoxide Dismutase and Pseudocatalase Increase Tolerance to Hg(II) in Thermus thermophilus HB27 by Maintaining the Reduced Bacillithiol Pool. mBio 2019; 10:mBio.00183-19. [PMID: 30940703 PMCID: PMC6445937 DOI: 10.1128/mbio.00183-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thermus thermophilus is a deep-branching thermophilic aerobe. It is a member of the Deinococcus-Thermus phylum that, together with the Aquificae, constitute the earliest branching aerobic bacterial lineages; therefore, this organism serves as a model for early diverged bacteria (R. K. Hartmann, J. Wolters, B. Kröger, S. Schultze, et al., Syst Appl Microbiol 11:243–249, 1989, https://doi.org/10.1016/S0723-2020(89)80020-7) whose natural heated habitat may contain mercury of geological origins (G. G. Geesey, T. Barkay, and S. King, Sci Total Environ 569-570:321–331, 2016, https://doi.org/10.1016/j.scitotenv.2016.06.080). T. thermophilus likely arose shortly after the oxidation of the biosphere 2.4 billion years ago. Studying T. thermophilus physiology provides clues about the origin and evolution of mechanisms for mercury and oxidative stress responses, the latter being critical for the survival and function of all extant aerobes. Mercury (Hg) is a widely distributed, toxic heavy metal with no known cellular role. Mercury toxicity has been linked to the production of reactive oxygen species (ROS), but Hg does not directly perform redox chemistry with oxygen. How exposure to the ionic form, Hg(II), generates ROS is unknown. Exposure of Thermus thermophilus to Hg(II) triggered ROS accumulation and increased transcription and activity of superoxide dismutase (Sod) and pseudocatalase (Pcat); however, Hg(II) inactivated Sod and Pcat. Strains lacking Sod or Pcat had increased oxidized bacillithiol (BSH) levels and were more sensitive to Hg(II) than the wild type. The ΔbshA Δsod and ΔbshA Δpcat double mutant strains were as sensitive to Hg(II) as the ΔbshA strain that lacks bacillithiol, suggesting that the increased sensitivity to Hg(II) in the Δsod and Δpcat mutant strains is due to a decrease of reduced BSH. Treatment of T. thermophilus with Hg(II) decreased aconitase activity and increased the intracellular concentration of free Fe, and these phenotypes were exacerbated in Δsod and Δpcat mutant strains. Treatment with Hg(II) also increased DNA damage. We conclude that sequestration of the redox buffering thiol BSH by Hg(II), in conjunction with direct inactivation of ROS-scavenging enzymes, impairs the ability of T. thermophilus to effectively metabolize ROS generated as a normal consequence of growth in aerobic environments.
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Mukkata K, Kantachote D, Wittayaweerasak B, Megharaj M, Naidu R. The potential of mercury resistant purple nonsulfur bacteria as effective biosorbents to remove mercury from contaminated areas. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2019. [DOI: 10.1016/j.bcab.2018.11.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Ranawat P, Rawat S. Metal-tolerant thermophiles: metals as electron donors and acceptors, toxicity, tolerance and industrial applications. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:4105-4133. [PMID: 29238927 DOI: 10.1007/s11356-017-0869-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 11/28/2017] [Indexed: 06/07/2023]
Abstract
Metal-tolerant thermophiles are inhabitants of a wide range of extreme habitats like solfatara fields, hot springs, mud holes, hydrothermal vents oozing out from metal-rich ores, hypersaline pools and soil crusts enriched with metals and other elements. The ability to withstand adverse environmental conditions, like high temperature, high metal concentration and sometimes high pH in their niche, makes them an interesting subject for understanding mechanisms behind their ability to deal with multiple duress simultaneously. Metals are essential for biological systems, as they participate in biochemistries that cannot be achieved only by organic molecules. However, the excess concentration of metals can disrupt natural biogeochemical processes and can impose toxicity. Thermophiles counteract metal toxicity via their unique cell wall, metabolic factors and enzymes that carry out metal-based redox transformations, metal sequestration by metallothioneins and metallochaperones as well as metal efflux. Thermophilic metal resistance is heterogeneous at both genetic and physiology levels and may be chromosomally, plasmid or transposon encoded with one or more genes being involved. These effective response mechanisms either individually or synergistically make proliferation of thermophiles in metal-rich habitats possibly. This article presents the state of the art and future perspectives of responses of thermophiles to metals at genetic as well as physiological levels.
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Affiliation(s)
- Preeti Ranawat
- Department of Botany and Microbiology, Hemvati Nandan Bahuguna Garhwal University, Srinagar (Garhwal), Uttarakhand, India
| | - Seema Rawat
- School of Life Sciences, Central University of Gujarat, Gandhinagar, Gujarat, India.
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Banerjee M, Roy G. Cleavage of Hg–C Bonds of Organomercurials Induced by ImOHSe via Two Distinct Pathways. Inorg Chem 2017; 56:12739-12750. [DOI: 10.1021/acs.inorgchem.7b01301] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Mainak Banerjee
- Department of Chemistry, School of Natural
Sciences, Shiv Nadar University, NH91, Dadri, Gautam Buddha Nagar, Uttar Pradesh 201314, India
| | - Gouriprasanna Roy
- Department of Chemistry, School of Natural
Sciences, Shiv Nadar University, NH91, Dadri, Gautam Buddha Nagar, Uttar Pradesh 201314, India
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Karri R, Banerjee M, Chalana A, Jha KK, Roy G. Activation of the Hg–C Bond of Methylmercury by [S2]-Donor Ligands. Inorg Chem 2017; 56:12102-12115. [DOI: 10.1021/acs.inorgchem.7b01048] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Ramesh Karri
- Department of Chemistry, School of Natural
Sciences, Shiv Nadar University, NH91, Dadri, Gautam Buddha Nagar, Uttar Pradesh 201314, India
| | - Mainak Banerjee
- Department of Chemistry, School of Natural
Sciences, Shiv Nadar University, NH91, Dadri, Gautam Buddha Nagar, Uttar Pradesh 201314, India
| | - Ashish Chalana
- Department of Chemistry, School of Natural
Sciences, Shiv Nadar University, NH91, Dadri, Gautam Buddha Nagar, Uttar Pradesh 201314, India
| | - Kunal Kumar Jha
- Department of Chemistry, School of Natural
Sciences, Shiv Nadar University, NH91, Dadri, Gautam Buddha Nagar, Uttar Pradesh 201314, India
| | - Gouriprasanna Roy
- Department of Chemistry, School of Natural
Sciences, Shiv Nadar University, NH91, Dadri, Gautam Buddha Nagar, Uttar Pradesh 201314, India
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Banerjee M, Karri R, Chalana A, Das R, Rai RK, Rawat KS, Pathak B, Roy G. Protection of Endogenous Thiols against Methylmercury with Benzimidazole-Based Thione by Unusual Ligand-Exchange Reactions. Chemistry 2017; 23:5696-5707. [DOI: 10.1002/chem.201605238] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Indexed: 12/27/2022]
Affiliation(s)
- Mainak Banerjee
- Department of Chemistry; School of Natural Sciences; Shiv Nadar University, NH91, Dadri; Gautam Buddha Nagar, UP 201314 India
| | - Ramesh Karri
- Department of Chemistry; School of Natural Sciences; Shiv Nadar University, NH91, Dadri; Gautam Buddha Nagar, UP 201314 India
| | - Ashish Chalana
- Department of Chemistry; School of Natural Sciences; Shiv Nadar University, NH91, Dadri; Gautam Buddha Nagar, UP 201314 India
| | - Ranajit Das
- Department of Chemistry; School of Natural Sciences; Shiv Nadar University, NH91, Dadri; Gautam Buddha Nagar, UP 201314 India
| | - Rakesh Kumar Rai
- Department of Chemistry; School of Natural Sciences; Shiv Nadar University, NH91, Dadri; Gautam Buddha Nagar, UP 201314 India
| | - Kuber Singh Rawat
- Discipline of Chemistry and Discipline of Metallurgy Engineering and Materials Science; Indian Institute of Technology (IIT) Indore; Indore, MP 453552 India
| | - Biswarup Pathak
- Discipline of Chemistry and Discipline of Metallurgy Engineering and Materials Science; Indian Institute of Technology (IIT) Indore; Indore, MP 453552 India
| | - Gouriprasanna Roy
- Department of Chemistry; School of Natural Sciences; Shiv Nadar University, NH91, Dadri; Gautam Buddha Nagar, UP 201314 India
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Ranawat P, Rawat S. Stress response physiology of thermophiles. Arch Microbiol 2017; 199:391-414. [DOI: 10.1007/s00203-016-1331-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 12/07/2016] [Accepted: 12/16/2016] [Indexed: 10/20/2022]
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Oyetibo GO, Miyauchi K, Suzuki H, Endo G. Mercury removal during growth of mercury tolerant and self-aggregating Yarrowia spp. AMB Express 2016; 6:99. [PMID: 27739052 PMCID: PMC5063827 DOI: 10.1186/s13568-016-0271-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 10/04/2016] [Indexed: 11/10/2022] Open
Abstract
Ecotoxicological implications of mercury (Hg) pollution of hydrosphere require effective Hg-removal strategies as antidote to the environmental problems. Mercury-tolerant yeasts, Yarrowia spp. Idd1 and Idd2 strains, were studied for intracellular accumulation and extracellular micro-precipitation of Hg during growth stage of the yeast strains. In a liquid medium containing 870 (±23.6) µg of bioavailable Hg2+, 419.0 µg Hg2+ (approx.) was taken up by the wet biomasses of the yeast strains after 48 h post-inoculation. Large portion of the adsorbed Hg was found in cell wall (approx. 49-83 %) and spheroplast (approx. 62-89 %). Negligible quantities of Hg were present in the mitochondria (0.02-0.02 %), and appreciable amount of Hg was observed in nuclei and cell debris (15.2-65.3 %) as evidence of bioaccumulation. Extracellular polymeric substances (EPS) produced by the growing Yarrowia cells was a complex of protein, carbohydrates and other substances, immobilizing 43.8 (±0.7)-58.7 (±1.0) % of initial Hg in medium as micro-precipitates, while 10.13 ± 0.4-39.2 ± 4.3 % Hg content was volatilized. Transmission electron microscopy coupled with X-ray energy dispersive spectrophotometry confirmed the cellular removal of Hg and formation of EPS-Hg complex colloids in the surrounding bulk solution as micro-precipitates in form of extracellular Hg-nanoparticles. Hg mass balance in the bio-sequestration experiment revealed excellent Hg removal (>97 %) from the medium (containing ≤16 μg ml-1 Hg2+) by the yeast strains via bioaccumulation, volatilization and micro-precipitation. The yeast strains are also effectively applicable in biological purification technology for Hg contaminated water because of their high self-aggregation activity and separatability from the aquatic environments. Graphical abstract Yarrowia species are oligotrophic marine yeasts that exhibited great potentials for mercuric ion remediation technologies, which are classified into four categories based on the process acting on the metal. These include immobilization through biosorption, compartmentation via bioaccumulation, separation from bulk solution via micro-precipitation upon EPS-Hg complex formation, and destruction that is a process to reduce the mercuric ion to metallic mercury.
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Extracellular mercury sequestration by exopolymeric substances produced by Yarrowia spp.: Thermodynamics, equilibria, and kinetics studies. J Biosci Bioeng 2016; 122:701-707. [DOI: 10.1016/j.jbiosc.2016.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/28/2016] [Accepted: 05/30/2016] [Indexed: 11/19/2022]
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Figueiredo NL, Canário J, O'Driscoll NJ, Duarte A, Carvalho C. Aerobic Mercury-resistant bacteria alter Mercury speciation and retention in the Tagus Estuary (Portugal). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2016; 124:60-67. [PMID: 26461264 DOI: 10.1016/j.ecoenv.2015.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 09/28/2015] [Accepted: 10/01/2015] [Indexed: 06/05/2023]
Abstract
Aerobic mercury-resistant bacteria were isolated from the sediments of two highly mercury-polluted areas of the Tagus Estuary (Barreiro and Cala do Norte) and one natural reserve area (Alcochete) in order to test their capacity to transform mercury. Bacterial species were identified using 16S rRNA amplification and sequencing techniques and the results indicate the prevalence of Bacillus sp. Resistance patterns to mercurial compounds were established by the determination of minimal inhibitory concentrations. Representative Hg-resistant bacteria were further tested for transformation pathways (reduction, volatilization and methylation) in cultures containing mercury chloride. Bacterial Hg-methylation was carried out by Vibrio fluvialis, Bacillus megaterium and Serratia marcescens that transformed 2-8% of total mercury into methylmercury in 48h. In addition, most of the HgR bacterial isolates showed Hg(2+)-reduction andHg(0)-volatilization resulting 6-50% mercury loss from the culture media. In summary, the results obtained under controlled laboratory conditions indicate that aerobic Hg-resistant bacteria from the Tagus Estuary significantly affect both the methylation and reduction of mercury and may have a dual face by providing a pathway for pollution dispersion while forming methylmercury, which is highly toxic for living organisms.
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Affiliation(s)
- Neusa L Figueiredo
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - João Canário
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Nelson J O'Driscoll
- Department of Earth & Environmental Sciences, Acadia University, K.C. Irving Environmental Science Center, 32 University Avenue, Wolfville, Nova Scotia, Canada
| | - Aida Duarte
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Cristina Carvalho
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal.
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Banerjee M, Karri R, Rawat KS, Muthuvel K, Pathak B, Roy G. Chemical Detoxification of Organomercurials. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/anie.201504413] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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17
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Banerjee M, Karri R, Rawat KS, Muthuvel K, Pathak B, Roy G. Chemical Detoxification of Organomercurials. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201504413] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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18
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Gugliandolo C, Lentini V, Spanò A, Maugeri T. New bacilli from shallow hydrothermal vents of Panarea Island (Italy) and their biotechnological potential. J Appl Microbiol 2012; 112:1102-12. [DOI: 10.1111/j.1365-2672.2012.05272.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Isolation and characterization of environmental bacteria capable of extracellular biosorption of mercury. Appl Environ Microbiol 2011; 78:1097-106. [PMID: 22156431 DOI: 10.1128/aem.06522-11] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Accumulation of toxic metals in the environment represents a public health and wildlife concern. Bacteria resistant to toxic metals constitute an attractive biomass for the development of systems to decontaminate soils, sediments, or waters. In particular, biosorption of metals within the bacterial cell wall or secreted extracellular polymeric substances (EPS) is an emerging process for the bioremediation of contaminated water. Here the isolation of bacteria from soil, effluents, and river sediments contaminated with toxic metals permitted the selection of seven bacterial isolates tolerant to mercury and associated with a mucoid phenotype indicative of the production of EPS. Inductively coupled plasma-optical emission spectroscopy and transmission electron microscopy in conjunction with X-ray energy dispersive spectrometry revealed that bacteria incubated in the presence of HgCl2 sequestered mercury extracellularly as spherical or amorphous deposits. Killed bacterial biomass incubated in the presence of HgCl2 also generated spherical extracellular mercury deposits, with a sequestration capacity (40 to 120 mg mercury per g [dry weight] of biomass) superior to that of live bacteria (1 to 2 mg mercury per g [dry weight] of biomass). The seven strains were shown to produce EPS, which were characterized by Fourier transform-infrared (FT-IR) spectroscopy and chemical analysis of neutral-carbohydrate, uronic acid, and protein contents. The results highlight the high potential of Hg-tolerant bacteria for applications in the bioremediation of mercury through biosorption onto the biomass surface or secreted EPS.
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Chatziefthimiou AD, Crespo-Medina M, Wang Y, Vetriani C, Barkay T. The isolation and initial characterization of mercury resistant chemolithotrophic thermophilic bacteria from mercury rich geothermal springs. Extremophiles 2007; 11:469-79. [PMID: 17401541 DOI: 10.1007/s00792-007-0065-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Accepted: 12/10/2006] [Indexed: 10/23/2022]
Abstract
Mercury rich geothermal springs are likely environments where mercury resistance is critical to microbial life and where microbe-mercury interactions may have evolved. Eleven facultative thermophilic and chemolithoautotrophic, thiosulfate oxidizing bacteria were isolated from thiosulfate enrichments of biofilms from mercury rich hot sulfidic springs in Mount Amiata, Italy. Some strains were highly resistant to mercury (>or=200 muM HgCl(2)) regardless of its presence or absence during primary enrichments, and three reduced ionic mercury to its elemental form. The gene encoding for the mercuric reductase enzyme (MerA), was amplified by PCR from seven strains. However, one highly resistant strain did not reduce mercury nor carried merA, suggesting an alternative resistance mechanism. All strains were members of the order Bacillales and were most closely related to previously described thermophiles belonging to the Firmicutes. Phylogenetic analyses clustered the MerA of the isolates in two supported novel nodes within the Firmicutes lineage and a comparison with the 16S rRNA gene tree suggested at least one case of horizontal gene transfer. Overall, the results show that the thermophilic thiosulfate oxidizing isolates were adapted to life in presence of mercury mostly, but not exclusively, by possessing MerA. These findings suggest that reduction of mercury by chemolithotrophic thermophilic bacteria may mobilize mercury from sulfur and iron deposits in geothermal environments.
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Affiliation(s)
- Aspassia D Chatziefthimiou
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Dr., New Brunswick, NJ 08901, USA
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Essa AMM, Creamer NJ, Brown NL, Macaskie LE. A new approach to the remediation of heavy metal liquid wastes via off-gases produced by Klebsiella pneumoniae M426. Biotechnol Bioeng 2006; 95:574-83. [PMID: 16958139 DOI: 10.1002/bit.20877] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
When the off-gas from an aerobic culture of Klebsiella pneumoniae M426 grown in the absence of added heavy metals was passed through a solution of Hg(2+), Cd(2+), Pb(2+), or Cu(2+) a yellow-white (Hg), white (Cd, Pb), or blue (Cu) precipitate was formed. Metal removal from solution was >97% within 2 h at initial concentrations of (as metal): Hg, 8.5; Cd, 12.6; Pb, 7.8; Cu, 9.5 mg/mL. Mercury was removed from solution at pH 2 and in up to 1 M NaCl. Energy dispersive X-ray microanalysis (EDX) of the precipitates showed them to comprise metal, sulfur and carbon in the case of Hg, Cd, and Pb, and, in the case of Cd and Pb, also oxygen. The pH of the solution increased by 1-2 units at an initial pH of 7 and by 4-5 units at an initial pH of 2. In the case of cadmium and lead, the presence of crystalline metal carbonates and hydroxides was confirmed by X-ray powder diffraction (XRD) analysis and additional peaks were seen which could not be assigned to known compounds in the diffraction file database. In the case of copper, hydroxides, and a form of copper sulfate, were found. In the case of mercury the XRD patterns could not be assigned to any known compound, except for HgCl in the solution at the acidic initial pH. The absence of sharp peaks in the pattern for the Hg-precipitate was indicative of poorly crystalline, nanocrystalline or amorphous material. The unknown mercury compound, since it contained non-carbonate carbon, was suggested to be derived from a volatile organothiol in the gases evolved from the culture. Analysis of the culture head gas by GC-MS showed the presence of dimethyldisulfide as a likely precipitant. No sulfur compound was found using XRD analysis in the case of cadmium and lead, although EDX analysis suggested this as a major component and the lack of XRD pattern is evidence for a non-crystalline metal-organothiol. The exact chemistry of the new materials remains to be elucidated but metal precipitation via a biogenic organothiol is a potentially effective approach to the remediation of aggressive metal wastes.
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Affiliation(s)
- A M M Essa
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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Essa AMM, Macaskie LE, Brown NL. A new method for mercury removal. Biotechnol Lett 2006; 27:1649-55. [PMID: 16247669 DOI: 10.1007/s10529-005-2722-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Accepted: 08/22/2005] [Indexed: 10/25/2022]
Abstract
A method is described for the removal of mercury from solution by using the off-gas produced from aerobic cultures of Klebsiella pneumoniae M426. Cells growing in Hg-supplemented medium produced a black precipitate containing mercury and sulphur. The ratio of Hg:S was determined as approximately 1:1 by analysis using proton-induced X-ray emission, suggesting precipitation of HgS within the culture. The outlet gases produced by a mercury-unsupplemented aerated culture were bubbled into an external chamber supplemented with up to 10 mg HgCl(2)/ml. A yellowish-white precipitate formed, corresponding to 99% removal of the mercury from solution within 120 min. Energy dispersive X-ray microanalysis showed that this metal precipitate consisted of mercury, carbon and sulphur. Formation of mercury carbonate was discounted since similar precipitation occurred at pH 2 and no oxygen was detected in the solid, which gave an X-ray powder pattern suggesting an amorphous material, with no evidence of HgS. Precipitation of mercury with a volatile organosulphur compound is suggested. Bio-precipitation of heavy metals by using culture off-gas is a useful approach because it can be used with concentrated or physiologically incompatible solutions. Since the metal precipitate is kept separate from the bacterial biomass, it can be managed independently.
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Affiliation(s)
- Ashraf M M Essa
- School of Biosciences, The University of Birmingham, Edgbaston, B15 2TT, Birmingham, UK
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