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Cui J, Xie Y, Sun T, Chen L, Zhang W. Deciphering and engineering photosynthetic cyanobacteria for heavy metal bioremediation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 761:144111. [PMID: 33352345 DOI: 10.1016/j.scitotenv.2020.144111] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/22/2020] [Accepted: 11/22/2020] [Indexed: 06/12/2023]
Abstract
Environmental pollution caused by heavy metals has received worldwide attentions due to their ubiquity, poor degradability and easy bioaccumulation in host cells. As one potential solution, photosynthetic cyanobacteria have been considered as promising remediation chassis and widely applied in various bioremediation processes of heavy-metals. Meanwhile, deciphering resistant mechanisms and constructing tolerant chassis towards heavy metals could greatly contribute to the successful application of the cyanobacteria-based bioremediation in the future. In this review, first we summarized recent application of cyanobacteria in heavy metals bioremediation using either live or dead cells. Second, resistant mechanisms and strategies for enhancing cyanobacterial bioremediation of heavy metals were discussed. Finally, potential challenges and perspectives for improving bioremediation of heavy metals by cyanobacteria were presented.
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Affiliation(s)
- Jinyu Cui
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, PR China
| | - Yaru Xie
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, PR China
| | - Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Center for Biosafety Research and Strategy, Tianjin University, Tianjin 300072, PR China; Law School of Tianjin University, Tianjin 300072, PR China.
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, PR China.
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, PR China; Center for Biosafety Research and Strategy, Tianjin University, Tianjin 300072, PR China; Law School of Tianjin University, Tianjin 300072, PR China
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102
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Manceau A, Nagy KL, Glatzel P, Bourdineaud JP. Acute Toxicity of Divalent Mercury to Bacteria Explained by the Formation of Dicysteinate and Tetracysteinate Complexes Bound to Proteins in Escherichia coli and Bacillus subtilis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:3612-3623. [PMID: 33629845 DOI: 10.1021/acs.est.0c05202] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Bacteria are the most abundant organisms on Earth and also the major life form affected by mercury (Hg) poisoning in aquatic and terrestrial food webs. In this study, we applied high energy-resolution X-ray absorption near edge structure (HR-XANES) spectroscopy to bacteria with intracellular concentrations of Hg as low as 0.7 ng/mg (ppm) for identifying the intracellular molecular forms and trafficking pathways of Hg in bacteria at environmentally relevant concentrations. Gram-positive Bacillus subtilis and Gram-negative Escherichia coli were exposed to three Hg species: HgCl2, Hg-dicysteinate (Hg(Cys)2), and Hg-dithioglycolate (Hg(TGA)2). In all cases, Hg was transformed into new two- and four-coordinate cysteinate complexes, interpreted to be bound, respectively, to the consensus metal-binding CXXC motif and zinc finger domains of proteins, with glutathione acting as a transfer ligand. Replacement of zinc cofactors essential to gene regulatory proteins with Hg would inhibit vital functions such as DNA transcription and repair and is suggested to be a main cause of Hg genotoxicity.
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Affiliation(s)
- Alain Manceau
- Université Grenoble Alpes, CNRS, ISTerre, CS 40700, 38058 Grenoble, France
| | - Kathryn L Nagy
- Department of Earth and Environmental Sciences, University of Illinois at Chicago, MC-186, 845 West Taylor Street, Chicago, Illinois 60607, United States
| | - Pieter Glatzel
- European Synchrotron Radiation Facility (ESRF), 71 Rue des Martyrs, 38000 Grenoble, France
| | - Jean-Paul Bourdineaud
- Institut Européen de Chimie et Biologie, Université de Bordeaux, CNRS, UMR 5234, 2 rue Escarpit, 33607 Pessac, France
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103
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Pöntinen AK, Top J, Arredondo-Alonso S, Tonkin-Hill G, Freitas AR, Novais C, Gladstone RA, Pesonen M, Meneses R, Pesonen H, Lees JA, Jamrozy D, Bentley SD, Lanza VF, Torres C, Peixe L, Coque TM, Parkhill J, Schürch AC, Willems RJL, Corander J. Apparent nosocomial adaptation of Enterococcus faecalis predates the modern hospital era. Nat Commun 2021; 12:1523. [PMID: 33750782 PMCID: PMC7943827 DOI: 10.1038/s41467-021-21749-5] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 02/05/2021] [Indexed: 12/20/2022] Open
Abstract
Enterococcus faecalis is a commensal and nosocomial pathogen, which is also ubiquitous in animals and insects, representing a classical generalist microorganism. Here, we study E. faecalis isolates ranging from the pre-antibiotic era in 1936 up to 2018, covering a large set of host species including wild birds, mammals, healthy humans, and hospitalised patients. We sequence the bacterial genomes using short- and long-read techniques, and identify multiple extant hospital-associated lineages, with last common ancestors dating back as far as the 19th century. We find a population cohesively connected through homologous recombination, a metabolic flexibility despite a small genome size, and a stable large core genome. Our findings indicate that the apparent hospital adaptations found in hospital-associated E. faecalis lineages likely predate the "modern hospital" era, suggesting selection in another niche, and underlining the generalist nature of this nosocomial pathogen.
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Affiliation(s)
- Anna K Pöntinen
- Department of Biostatistics, Faculty of Medicine, University of Oslo, Oslo, Norway.
| | - Janetta Top
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Sergio Arredondo-Alonso
- Department of Biostatistics, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Ana R Freitas
- UCIBIO/REQUIMTE, Laboratory of Microbiology, Biological Sciences Department, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Carla Novais
- UCIBIO/REQUIMTE, Laboratory of Microbiology, Biological Sciences Department, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Rebecca A Gladstone
- Department of Biostatistics, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Maiju Pesonen
- Oslo Centre for Biostatistics and Epidemiology (OCBE), Oslo University Hospital Research Support Services, Oslo, Norway
| | - Rodrigo Meneses
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Henri Pesonen
- Department of Biostatistics, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - John A Lees
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Dorota Jamrozy
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
| | | | | | - Carmen Torres
- Department of Food and Agriculture, Area of Biochemistry and Molecular Biology, University of La Rioja, Logroño, Spain
| | - Luisa Peixe
- UCIBIO/REQUIMTE, Laboratory of Microbiology, Biological Sciences Department, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Teresa M Coque
- Department of Microbiology, Ramón y Cajal Institute for Health Research Ramón y Cajal University Hospital, Madrid, Spain
- CIBER in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Julian Parkhill
- Wellcome Sanger Institute, Cambridge, UK
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Anita C Schürch
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Rob J L Willems
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jukka Corander
- Department of Biostatistics, Faculty of Medicine, University of Oslo, Oslo, Norway.
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK.
- Helsinki Institute of Information Technology, Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland.
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104
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Etique M, Bouchet S, Byrne JM, ThomasArrigo LK, Kaegi R, Kretzschmar R. Mercury Reduction by Nanoparticulate Vivianite. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:3399-3407. [PMID: 33554594 PMCID: PMC7931808 DOI: 10.1021/acs.est.0c05203] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 01/15/2021] [Accepted: 01/22/2021] [Indexed: 05/24/2023]
Abstract
Mercury (Hg) is a toxic trace element of global environmental concern which has been increasingly dispersed into the environment since the industrial revolution. In aquatic and terrestrial systems, Hg can be reduced to elemental Hg (Hg0) and escape to the atmosphere or converted to methylmercury (MeHg), a potent neurotoxin that accumulates in food webs. FeII-bearing minerals such as magnetite, green rusts, siderite, and mackinawite are recognized HgII reducers. Another potentially Hg-reducing mineral, which commonly occurs in Fe- and organic/P-rich sediments and soils, is the ferrous iron phosphate mineral vivianite (FeII3(PO4)2·8H2O), but its reaction with HgII has not been studied to date. Here, nanoparticulate vivianite (particle size ∼ 50 nm; FeII content > 98%) was chemically synthesized and characterized by a combination of chemical, spectroscopic, and microscopic analyses. Its ability to reduce HgII was investigated at circumneutral pH under anoxic conditions over a range of FeII/HgII ratios (0.1-1000). For FeII/HgII ratios ≥1, which are representative of natural environments, HgII was very quickly and efficiently reduced to Hg0. The ability of vivianite to reduce HgII was found to be similar to those of carbonate green rust and siderite, two of the most effective Hg-reducing minerals. Our results suggest that vivianite may be involved in abiotic HgII reduction in Fe and organic/P-rich soils and sediments, potentially contributing to Hg evasion while also limiting MeHg formation in these ecosystems.
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Affiliation(s)
- Marjorie Etique
- Soil Chemistry Group, Institute of Biogeochemistry and
Pollutant Dynamics, Department of Environmental Systems Science, ETH
Zürich, Universitätstrasse 16, CHN, 8092 Zürich,
Switzerland
| | - Sylvain Bouchet
- Soil Chemistry Group, Institute of Biogeochemistry and
Pollutant Dynamics, Department of Environmental Systems Science, ETH
Zürich, Universitätstrasse 16, CHN, 8092 Zürich,
Switzerland
| | - James M. Byrne
- School of Earth Sciences, University of
Bristol, Wills Memorial Building, Queens Road, BS8 1RJ Bristol,
U.K.
| | - Laurel K. ThomasArrigo
- Soil Chemistry Group, Institute of Biogeochemistry and
Pollutant Dynamics, Department of Environmental Systems Science, ETH
Zürich, Universitätstrasse 16, CHN, 8092 Zürich,
Switzerland
| | - Ralf Kaegi
- Eawag, Swiss Federal Institute of Aquatic
Science and Technology, Überlandstrasse 133, 8600 Dübendorf,
Switzerland
| | - Ruben Kretzschmar
- Soil Chemistry Group, Institute of Biogeochemistry and
Pollutant Dynamics, Department of Environmental Systems Science, ETH
Zürich, Universitätstrasse 16, CHN, 8092 Zürich,
Switzerland
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105
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Salam LB, Obayori OS, Ilori MO, Amund OO. Acenaphthene biodegradation and structural and functional metagenomics of the microbial community of an acenaphthene-enriched animal charcoal polluted soil. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2021. [DOI: 10.1016/j.bcab.2021.101951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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106
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He P, Huang J, Yu Z, Xu X, Raga R, Lü F. Antibiotic resistance contamination in four Italian municipal solid waste landfills sites spanning 34 years. CHEMOSPHERE 2021; 266:129182. [PMID: 33333336 DOI: 10.1016/j.chemosphere.2020.129182] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/28/2020] [Accepted: 11/30/2020] [Indexed: 06/12/2023]
Abstract
Municipal solid waste landfill is now recognized as a significant reservoir of antibiotics and antibiotic resistance genes (ARGs). This study investigates the contamination of antibiotics resistance, in 10 leachate samples collected from four MSW landfills in north Italy spanning 34 years, including ARGs as well as mobile genetic element (MGEs). Antibiotics (0-434740 ng/L) and ARGs (5.56-6.85 × 105copies/μL leachate) were found in leachate. Abundances of the measured ARGs were found to be clustered into two groups with different changing tendencies with landfilling age in different landfills. Even though some antibiotics were banned or limited in Italy, they were found to still occur in landfills and drive the long-term contamination of ARGs indirectly, indicating the persistence of antibiotic resistance. What's more, the complexity of antibiotic resistance in leachate was found to synthetically relate to antibiotics, metals, microbes and MGEs presenting that Mn, SMX and EFC influence positively (p < 0.01) the contamination of tetW, tetQ, tetM, tetA, ermB, and cat, contributing importantly in new leachate. This study discusses the AR pollution of leachate in Italy where antibiotics are used the most in Europe, less reported in literatures. Our results suggest that a full-scale view for landfill antibiotics resistance should be considered with history of landfills, use of antibiotics and different phase in landfills, with both "relative static" and "dynamic tracking" perspective to focus on the principal antibiotic-resistance pollutants for leachate treatment, and raise the attention for landfill post-closure care and landfill mining.
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Affiliation(s)
- Pinjing He
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, PR China; Institute of Waste Treatment & Reclamation, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China
| | - Jinghua Huang
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China
| | - Zhuofeng Yu
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, PR China
| | - Xian Xu
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, PR China
| | - Roberto Raga
- ICEA, Department of Civil, Environmental and Architectural Engineering, University of Padova, Via Marzolo, 9, 35131, Padova, Italy.
| | - Fan Lü
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
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107
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Arregui G, Hipólito P, Pallol B, Lara-Dampier V, García-Rodríguez D, Varela HP, Tavakoli Zaniani P, Balomenos D, Paape T, Coba de la Peña T, Lucas MM, Pueyo JJ. Mercury-Tolerant Ensifer medicae Strains Display High Mercuric Reductase Activity and a Protective Effect on Nitrogen Fixation in Medicago truncatula Nodules Under Mercury Stress. FRONTIERS IN PLANT SCIENCE 2021; 11:560768. [PMID: 33519831 PMCID: PMC7840509 DOI: 10.3389/fpls.2020.560768] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 12/22/2020] [Indexed: 05/27/2023]
Abstract
Mercury (Hg) is extremely toxic for all living organisms. Hg-tolerant symbiotic rhizobia have the potential to increase legume tolerance, and to our knowledge, the mechanisms underlying Hg tolerance in rhizobia have not been investigated to date. Rhizobial strains of Ensifer medicae, Rhizobium leguminosarum bv. trifolii and Bradyrhizobium canariense previously isolated from severely Hg-contaminated soils showed different levels of Hg tolerance. The ability of the strains to reduce mercury Hg2+ to Hg0, a volatile and less toxic form of mercury, was assessed using a Hg volatilization assay. In general, tolerant strains displayed high mercuric reductase activity, which appeared to be inducible in some strains when grown at a sub-lethal HgCl2 concentration. A strong correlation between Hg tolerance and mercuric reductase activity was observed for E. medicae strains, whereas this was not the case for the B. canariense strains, suggesting that additional Hg tolerance mechanisms could be playing a role in B. canariense. Transcript abundance from merA, the gene that encodes mercuric reductase, was quantified in tolerant and sensitive E. medicae and R. leguminosarum strains. Tolerant strains presented higher merA expression than sensitive ones, and an increase in transcript abundance was observed for some strains when bacteria were grown in the presence of a sub-lethal HgCl2 concentration. These results suggest a regulation of mercuric reductase in rhizobia. Expression of merA genes and mercuric reductase activity were confirmed in Medicago truncatula nodules formed by a sensitive or a tolerant E. medicae strain. Transcript accumulation in nodules formed by the tolerant strain increased when Hg stress was applied, while a significant decrease in expression occurred upon stress application in nodules formed by the Hg-sensitive strain. The effect of Hg stress on nitrogen fixation was evaluated, and in our experimental conditions, nitrogenase activity was not affected in nodules formed by the tolerant strain, while a significant decrease in activity was observed in nodules elicited by the Hg-sensitive bacteria. Our results suggest that the combination of tolerant legumes with tolerant rhizobia constitutes a potentially powerful tool in the bioremediation of Hg-contaminated soils.
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Affiliation(s)
- Gabriela Arregui
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | - Pablo Hipólito
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | - Beatriz Pallol
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | - Victoria Lara-Dampier
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | - Diego García-Rodríguez
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | - Higinio P. Varela
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | | | | | - Timothy Paape
- Brookhaven National Laboratory, Upton, NY, United States
| | | | - M. Mercedes Lucas
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | - José J. Pueyo
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
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108
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Abstract
Aluminosilicate clay minerals are often a major component of soils and sediments and many of these clays contain structural Fe (e.g., smectites and illites). Structural Fe(III) in smectite clays is redox active and can be reduced to Fe(II) by biotic and abiotic processes. Fe(II)-bearing minerals such as magnetite and green rust can reduce Hg(II) to Hg(0); however, the ability of other environmentally relevant Fe(II) phases, such as structural Fe(II) in smectite clays, to reduce Hg(II) is largely undetermined. We conducted experiments examining the potential for reduction of Hg(II) by smectite clay minerals containing 0–25 wt% Fe. Fe(III) in the clays (SYn-1 synthetic mica-montmorillonite, SWy-2 montmorillonite, NAu-1 and NAu-2 nontronite, and a nontronite from Cheney, Washington (CWN)) was reduced to Fe(II) using the citrate-bicarbonate-dithionite method. Experiments were initiated by adding 500 µM Hg(II) to reduced clay suspensions (4 g clay L−1) buffered at pH 7.2 in 20 mM 3-morpholinopropane-1-sulfonic acid (MOPS). The potential for Hg(II) reduction in the presence of chloride (0–10 mM) and at pH 5–9 was examined in the presence of reduced NAu-1. Analysis of the samples by Hg LIII-edge X-ray absorption fine structure (XAFS) spectroscopy indicated little to no reduction of Hg(II) by SYn-1 (0% Fe), while reduction of Hg(II) to Hg(0) was observed in the presence of reduced SWy-2, NAu-1, NAu-2, and CWN (2.8–24.8% Fe). Hg(II) was reduced to Hg(0) by NAu-1 at all pH and chloride concentrations examined. These results suggest that Fe(II)-bearing smectite clays may contribute to Hg(II) reduction in suboxic/anoxic soils and sediments.
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109
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Ohshiro Y, Uraguchi S, Nakamura R, Takanezawa Y, Kiyono M. Cadmium transport activity of four mercury transporters (MerC, MerE, MerF and MerT) and effects of the periplasmic mercury-binding protein MerP on Mer-dependent cadmium uptake. FEMS Microbiol Lett 2020; 367:5942867. [PMID: 33119092 DOI: 10.1093/femsle/fnaa177] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/27/2020] [Indexed: 11/13/2022] Open
Abstract
Mercury superfamily proteins, i.e. inner membrane-spanning proteins (MerC, MerE, MerF and MerT) and a periplasmic mercury-binding protein (MerP), transport mercury into the cytoplasm. A previous study demonstrated that a Mer transporter homolog exhibits cadmium transport activity; based on this, the present study aimed to evaluate the cadmium transport activity of MerC, MerE, MerF and MerT and the effects of MerP co-expression in Escherichia coli. Bacteria expressing MerC, MerE, MerF or MerT without MerP were more sensitive to cadmium and significantly absorbed more cadmium than did the control strain. Expression of MerP in combination with MerC, MerE, MerF or MerT increased the bacterial sensitivity to cadmium and cadmium accumulation compared to a single expression of MerC, MerE, MerF or MerT. Cadmium uptake mediated by MerC, MerE, MerF or MerT was inhibited under cold or acidic conditions. These findings suggest that MerC, MerE, MerF and MerT are broad-spectrum heavy metal transporters that mediate both mercury and cadmium transport into cells and that MerP accelerates the cadmium transport ability of MerC, MerE, MerF and MerT.
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Affiliation(s)
- Yuka Ohshiro
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Shimpei Uraguchi
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Ryosuke Nakamura
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Yasukazu Takanezawa
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Masako Kiyono
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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110
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Isaure MP, Albertelli M, Kieffer I, Tucoulou R, Petrel M, Gontier E, Tessier E, Monperrus M, Goñi-Urriza M. Relationship Between Hg Speciation and Hg Methylation/Demethylation Processes in the Sulfate-Reducing Bacterium Pseudodesulfovibrio hydrargyri: Evidences From HERFD-XANES and Nano-XRF. Front Microbiol 2020; 11:584715. [PMID: 33154741 PMCID: PMC7591507 DOI: 10.3389/fmicb.2020.584715] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 09/17/2020] [Indexed: 01/09/2023] Open
Abstract
Microorganisms are key players in the transformation of mercury into neurotoxic methylmercury (MeHg). Nevertheless, this mechanism and the opposite MeHg demethylation remain poorly understood. Here, we explored the impact of inorganic mercury (IHg) and MeHg concentrations from 0.05 to 50 μM on the production and degradation of MeHg in two sulfate-reducing bacteria, Pseudodesulfovibrio hydrargyri BerOc1 able to methylate and demethylate mercury and Desulfovibrio desulfuricans G200 only able to demethylate MeHg. MeHg produced by BerOc1 increased with increasing IHg concentration with a maximum attained for 5 μM, and suggested a saturation of the process. MeHg was mainly found in the supernatant suggesting its export from the cell. Hg L3-edge High- Energy-Resolution-Fluorescence-Detected-X-ray-Absorption-Near-Edge-Structure spectroscopy (HERFD-XANES) identified MeHg produced by BerOc1 as MeHg-cysteine2 form. A dominant tetracoordinated βHgS form was detected for BerOc1 exposed to the lowest IHg concentrations where methylation was detected. In contrast, at the highest exposure (50 μM) where Hg methylation was abolished, Hg species drastically changed suggesting a role of Hg speciation in the production of MeHg. The tetracoordinated βHgS was likely present as nano-particles as suggested by transmission electron microscopy combined to X-ray energy dispersive spectroscopy (TEM-X-EDS) and nano-X ray fluorescence (nano-XRF). When exposed to MeHg, the production of IHg, on the contrary, increased with the increase of MeHg exposure until 50 μM for both BerOc1 and G200 strains, suggesting that demethylation did not require intact biological activity. The formed IHg species were identified as various tetracoordinated Hg-S forms. These results highlight the important role of thiol ligands and Hg coordination in Hg methylation and demethylation processes.
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Affiliation(s)
- Marie-Pierre Isaure
- Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, MIRA, IPREM, Pau, France
| | - Marine Albertelli
- Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, MIRA, IPREM, Pau, France
| | - Isabelle Kieffer
- FAME-UHD, BM16 Beamline, European Synchrotron Radiation Facility (ESRF), BP220, Grenoble, France.,CNRS, IRD, Irstea, Météo France, OSUG, FAME, Université Grenoble Alpes, Grenoble, France
| | - Rémi Tucoulou
- ID16B Beamline, European Synchrotron Radiation Facility (ESRF), BP220, Grenoble, France
| | - Melina Petrel
- Bordeaux Imaging Center UMS 3420 CNRS - US4 INSERM, Université de Bordeaux, Pôle d'imagerie Électronique, Bordeaux, France
| | - Etienne Gontier
- Bordeaux Imaging Center UMS 3420 CNRS - US4 INSERM, Université de Bordeaux, Pôle d'imagerie Électronique, Bordeaux, France
| | - Emmanuel Tessier
- Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, MIRA, IPREM, Pau, France
| | - Mathilde Monperrus
- Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, MIRA, IPREM, Anglet, France
| | - Marisol Goñi-Urriza
- Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, MIRA, IPREM, Pau, France
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111
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Yang H, Wei SH, Hobman JL, Dodd CER. Antibiotic and Metal Resistance in Escherichia coli Isolated from Pig Slaughterhouses in the United Kingdom. Antibiotics (Basel) 2020; 9:antibiotics9110746. [PMID: 33126748 PMCID: PMC7692696 DOI: 10.3390/antibiotics9110746] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 10/18/2020] [Accepted: 10/27/2020] [Indexed: 12/20/2022] Open
Abstract
Antimicrobial resistance is currently an important concern, but there are few data on the co-presence of metal and antibiotic resistance in potentially pathogenic Escherichia coli entering the food chain from pork, which may threaten human health. We have examined the phenotypic and genotypic resistances to 18 antibiotics and 3 metals (mercury, silver, and copper) of E. coli from pig slaughterhouses in the United Kingdom. The results showed resistances to oxytetracycline, streptomycin, sulphonamide, ampicillin, chloramphenicol, trimethoprim–sulfamethoxazole, ceftiofur, amoxicillin–clavulanic acid, aztreonam, and nitrofurantoin. The top three resistances were oxytetracycline (64%), streptomycin (28%), and sulphonamide (16%). Two strains were resistant to six kinds of antibiotics. Three carried the blaTEM gene. Fifteen strains (18.75%) were resistant to 25 µg/mL mercury and five (6.25%) of these to 50 µg/mL; merA and merC genes were detected in 14 strains. Thirty-five strains (43.75%) showed resistance to silver, with 19 possessing silA, silB, and silE genes. Fifty-five strains (68.75%) were resistant to 8 mM copper or above. Seven contained the pcoE gene. Some strains were multi-resistant to antibiotics, silver, and copper. The results in this study, based on strains isolated between 2007 and 2010, will aid understanding about the effects of strategies to reduce resistance and mechanisms of antimicrobial resistance (AMR).
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Affiliation(s)
- Hongyan Yang
- College of Life Sciences, Northeast Forestry University, Harbin 150040, China
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Leicestershire LE12 5RD, UK; (S.-H.W.); (J.L.H.); (C.E.R.D.)
- Correspondence:
| | - Shao-Hung Wei
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Leicestershire LE12 5RD, UK; (S.-H.W.); (J.L.H.); (C.E.R.D.)
- JHL Biotech, Zhubei City, Hsinchu County 302, Taiwan
| | - Jon L. Hobman
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Leicestershire LE12 5RD, UK; (S.-H.W.); (J.L.H.); (C.E.R.D.)
| | - Christine E. R. Dodd
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Leicestershire LE12 5RD, UK; (S.-H.W.); (J.L.H.); (C.E.R.D.)
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112
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Zheng R, Wu S, Sun C. MerF is a novel regulator of deep-sea Pseudomonas stutzeri flagellum biogenesis and motility. Environ Microbiol 2020; 23:110-125. [PMID: 33047460 DOI: 10.1111/1462-2920.15275] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 10/05/2020] [Accepted: 10/08/2020] [Indexed: 12/17/2022]
Abstract
MerF, a proposed bacterial mercury transporter, was surprisingly found to play key roles in the flagellum biogenesis and motility but not mercuric resistance of the deep-sea bacterium Pseudomonas stutzeri 273 in our previous study. However, the mechanism behind this interesting discovery has not been elucidated. Here, we firstly applied the combined transcriptomic and proteomic analysis to the P. stutzeri 273 wild type and merF deletion mutant. The results showed that expressions of extracellular flagellar components and FliS, a key factor controlling the biogenesis of extracellular flagellar filament, were significantly downregulated in the merF deletion mutant. In combination of genetic and biochemical methods, MerF was further demonstrated to regulate the expression of fliS via directly binding to its promoter, which is consistent with the discovery that MerF is essential for bacterial flagellum biogenesis and motility. Importantly, the expression of merF and fliS could be simultaneously upregulated by different heavy metals and MerF homologues exist in both bacterial and archaeal domains. To the best of our knowledge, this is the first report linking the heavy metal transporter and the flagellum biogenesis and motility in microorganisms, which provides a good model to investigate the unexplored adaptation strategies of deep-sea microbes against harsh conditions.
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Affiliation(s)
- Rikuan Zheng
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth Science, University of Chinese Academy of Sciences, Beijing, China.,Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Shimei Wu
- College of Life Sciences, Qingdao University, Qingdao, China
| | - Chaomin Sun
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Center of Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
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113
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Durand A, Maillard F, Foulon J, Chalot M. Interactions between Hg and soil microbes: microbial diversity and mechanisms, with an emphasis on fungal processes. Appl Microbiol Biotechnol 2020; 104:9855-9876. [PMID: 33043392 DOI: 10.1007/s00253-020-10795-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 07/06/2020] [Accepted: 07/21/2020] [Indexed: 11/25/2022]
Abstract
Mercury (Hg) is a highly toxic metal with no known biological function, and it can be highly bioavailable in terrestrial ecosystems. Although fungi are important contributors to a number of soil processes including plant nutrient uptake and decomposition, little is known about the effect of Hg on fungi. Fungi accumulate the largest amount of Hg and are the organisms capable of the highest bioaccumulation of Hg. While referring to detailed mechanisms in bacteria, this mini-review emphasizes the progress made recently on this topic and represents the first step towards a better understanding of the mechanisms underlying Hg tolerance and accumulation in fungal species and hence on the role of fungi within the Hg cycle at Hg-contaminated sites. KEY POINTS: • The fungal communities are more resilient than bacterial communities to Hg exposure. • The exposure to Hg is a threat to microbial soil functions involved in both C and nutrient cycles. • Fungal (hyper)accumulation of Hg may be important for the Hg cycle in terrestrial environments. • Understanding Hg tolerance and accumulation by fungi may lead to new remediation biotechnologies.
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Affiliation(s)
- Alexis Durand
- Laboratoire Chrono-Environnement, UMR 6249, Université de Bourgogne Franche-Comté, Pôle Universitaire du Pays de Montbéliard, 4 place Tharradin, BP 71427, 25211, Montbéliard, France
- Laboratoire Sols et Environnement, UMR 1120, Université de Lorraine - INRAE, 2 avenue de la Forêt de Haye BP 20 163, 54505, Vandœuvre-lès-Nancy, France
| | - François Maillard
- Laboratoire Chrono-Environnement, UMR 6249, Université de Bourgogne Franche-Comté, Pôle Universitaire du Pays de Montbéliard, 4 place Tharradin, BP 71427, 25211, Montbéliard, France
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, 55108, USA
| | - Julie Foulon
- Laboratoire Chrono-Environnement, UMR 6249, Université de Bourgogne Franche-Comté, Pôle Universitaire du Pays de Montbéliard, 4 place Tharradin, BP 71427, 25211, Montbéliard, France
- Institut des Sciences de la Mer de Rimouski, Université du Québec à Rimouski, 310 Allée des Ursulines, C.P. 3300, Rimouski, QC, G5L 3A1, Canada
| | - Michel Chalot
- Laboratoire Chrono-Environnement, UMR 6249, Université de Bourgogne Franche-Comté, Pôle Universitaire du Pays de Montbéliard, 4 place Tharradin, BP 71427, 25211, Montbéliard, France.
- Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, 54506, Vandoeuvre-les-Nancy, France.
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114
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Mazumder P, Sharma SK, Taki K, Kalamdhad AS, Kumar M. Microbes involved in arsenic mobilization and respiration: a review on isolation, identification, isolates and implications. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2020; 42:3443-3469. [PMID: 32170513 DOI: 10.1007/s10653-020-00549-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 02/29/2020] [Indexed: 06/10/2023]
Abstract
Microorganisms play an important role in arsenic (As) cycling in the environment. Microbes mobilize As directly or indirectly, and natural/geochemical processes such as sulphate and iron reduction, oxidative sulphide mineral dissolution, arsenite (AsO33-) oxidation and arsenate (AsO43-) respiration further aid in As cycle in the environment. Arsenate serves as an electron donor for the microbes during anaerobic conditions in the sediment. The present work reviews the recent development in As contamination, various As-metabolizing microbes and their phylogenetic diversity, to understand the role of microbial communities in As respiration and mobilization. It also summarizes the contemporary understanding of the intricate biochemistry and molecular biology of natural As metabolisms. Some successful examples of engineered microbes by harnessing these natural mechanisms for effective remediation are also discussed. The study indicates that there is an exigent need to have a clear understanding of environmental aspects of As mobilization and subsequent oxidation-reduction by a suitable microbial consortium.
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Affiliation(s)
- Payal Mazumder
- Centre for the Environment, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Subhash Kumar Sharma
- Environmental Engineering, National Institute of Technology, Tiruchirappalli, Tamil Nadu, India
| | - Kaling Taki
- Discipline of Civil Engineering, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat, 382355, India
| | - Ajay S Kalamdhad
- Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Manish Kumar
- Discipline of Earth Sciences, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat, 382355, India.
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115
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Mello IS, Targanski S, Pietro-Souza W, Frutuoso Stachack FF, Terezo AJ, Soares MA. Endophytic bacteria stimulate mercury phytoremediation by modulating its bioaccumulation and volatilization. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 202:110818. [PMID: 32590206 DOI: 10.1016/j.ecoenv.2020.110818] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/24/2020] [Accepted: 05/25/2020] [Indexed: 05/27/2023]
Abstract
The quantification, efficiency, and possible mechanisms of mercury phytoremediation by endophytic bacteria are poorly understood. Here we selected 8 out of 34 previously isolated endophytic bacterial strains with a broad resistance profile to metals and 11 antibiotics: Acinetobacter baumannii BacI43, Bacillus sp. BacI34, Enterobacter sp. BacI14, Klebsiella pneumoniae BacI20, Pantoea sp. BacI23, Pseudomonas sp. BacI7, Pseudomonas sp. BacI38, and Serratia marcescens BacI56. Except for Klebsiella pneumoniae BacI20, the other seven bacterial strains promoted maize growth on a mercury-contaminated substrate. Acinetobacter baumannii BacI43 and Bacillus sp. BacI34 increased total dry biomass by approximately 47%. The bacteria assisted mercury remediation by decreasing the metal amount in the substrate, possibly by promoting its volatilization. The plants inoculated with Serratia marcescens BacI56 and Pseudomonas sp. BacI38 increased mercury volatilization to 47.16% and 62.42%, respectively. Except for Bacillus sp. BacI34 and Pantoea sp. BacI23, the other six bacterial strains favored mercury bioaccumulation in plant tissues. Endophytic bacteria-assisted phytoremediation contributed to reduce the substrate toxicity assessed in different model organisms. The endophytic bacterial strains selected herein are potential candidates for assisted phytoremediation that shall help reduce environmental toxicity of mercury-contaminated soils.
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Affiliation(s)
- Ivani Souza Mello
- Laboratório de Biotecnologia e Ecologia Microbiana, Departamento de Botânica e Ecologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Sabrina Targanski
- Laboratório de Biotecnologia e Ecologia Microbiana, Departamento de Botânica e Ecologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - William Pietro-Souza
- Instituto Federal de Educação, Ciência e Tecnologia de Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | | | - Ailton Jose Terezo
- Central Analítica de Combustíveis, Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Marcos Antônio Soares
- Laboratório de Biotecnologia e Ecologia Microbiana, Departamento de Botânica e Ecologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso, Brazil.
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116
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Akkoyun MB, Ozdemir S, Kilinc E, Birhanli E, Aygün A, Sen F. Resistance, removal, and bioaccumulation of Ni (II) and Co (II) and their impacts on antioxidant enzymes of Anoxybacillus mongoliensis. Comp Biochem Physiol C Toxicol Pharmacol 2020; 235:108790. [PMID: 32416322 DOI: 10.1016/j.cbpc.2020.108790] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/01/2020] [Accepted: 05/06/2020] [Indexed: 12/22/2022]
Abstract
In this study, it was hypothesis that A. mongoliensis could be used as bioindicator for Ni (II) and Co (II). Thus, Ni (II) and Co (II) resistance, removal, bioaccumulation, and the impacts of them on antioxidant enzyme systems of thermophilic Anoxybacillus mongoliensis were investigated in details. The bioaccumulation of Ni (II) and Co (II) on the cell membrane of thermophilic A. mongoliensis, variations on surface macrostructure and functionality by FT-IR and SEM, and determination of antioxidant enzyme activities were also tested. The highest bioaccumulation values of Co (II) and Ni (II) were detected as 102.0 mg metal/g of dry bacteria at 10 mg/L for the 12th h and 90.4 mg metal/g of dry bacteria for the 24th h, respectively, and the highest Ni (II) and Co (II) cell membrane bioaccumulation capacities of A. mongoliensis were determined as 268.5 and 274.9 mg metal/g wet membrane, respectively at the 24th h. In addition, increasing on SOD and CAT activities were observed on depend of concentration of Ni (II) and Co (II) with respect to control. The antioxidant enzyme activity results also indicated that A. mongoliensis might be used as a bioindicator for Ni (II) and Co (II) pollution in environmental water specimens.
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Affiliation(s)
| | - Sadin Ozdemir
- Food Processing Programme, Technical Science Vocational School, Mersin University, TR-33343 Yenisehir, Mersin, Turkey
| | - Ersin Kilinc
- Department of Chemistry and Chemical Processing Technologies, Vocational School of Technical Sciences, Dicle University, Diyarbakır TR-21200, Turkey
| | - Emre Birhanli
- Department of Biology, Faculty of Science and Art, Inonu University, 44280 Malatya, Turkey.
| | - Ayşenur Aygün
- Sen Research Group, Department of Biochemistry, Faculty of Art and Science, Dumlupinar University, 43000, Turkey
| | - Fatih Sen
- Sen Research Group, Department of Biochemistry, Faculty of Art and Science, Dumlupinar University, 43000, Turkey.
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117
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Hall JPJ, Harrison E, Pärnänen K, Virta M, Brockhurst MA. The Impact of Mercury Selection and Conjugative Genetic Elements on Community Structure and Resistance Gene Transfer. Front Microbiol 2020; 11:1846. [PMID: 32849443 PMCID: PMC7419628 DOI: 10.3389/fmicb.2020.01846] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/15/2020] [Indexed: 12/11/2022] Open
Abstract
Carriage of resistance genes can underpin bacterial survival, and by spreading these genes between species, mobile genetic elements (MGEs) can potentially protect diversity within microbial communities. The spread of MGEs could be affected by environmental factors such as selection for resistance, and biological factors such as plasmid host range, with consequences for individual species and for community structure. Here we cultured a focal bacterial strain, Pseudomonas fluorescens SBW25, embedded within a soil microbial community, with and without mercury selection, and with and without mercury resistance plasmids (pQBR57 or pQBR103), to investigate the effects of selection and resistance gene introduction on (1) the focal species; (2) the community as a whole; (3) the spread of the introduced mer resistance operon. We found that P. fluorescens SBW25 only escaped competitive exclusion by other members of community under mercury selection, even when it did not begin with a mercury resistance plasmid, due to its propensity to acquire resistance from the community by horizontal gene transfer. Mercury pollution had a significant effect on community structure, decreasing alpha diversity within communities while increasing beta diversity between communities, a pattern that was not affected by the introduction of mercury resistance plasmids by P. fluorescens SBW25. Nevertheless, the introduced merA gene spread to a phylogenetically diverse set of recipients over the 5 weeks of the experiment, as assessed by epicPCR. Our data demonstrates how the effects of MGEs can be experimentally assessed for individual lineages, the wider community, and for the spread of adaptive traits.
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Affiliation(s)
- James P J Hall
- Department of Evolution, Ecology and Behaviour, Institute of Integrative Biology, The University of Liverpool, Liverpool, United Kingdom.,Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom.,Department of Biology, University of York, York, United Kingdom
| | - Ellie Harrison
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom
| | | | - Marko Virta
- Department of Microbiology, University of Helsinki, Helsinki, Finland
| | - Michael A Brockhurst
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom.,Division of Evolution and Genomic Sciences, School of Biological Sciences, The University of Manchester, Manchester, United Kingdom
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118
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Singh S, Kumar V. Mercury detoxification by absorption, mercuric ion reductase, and exopolysaccharides: a comprehensive study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:27181-27201. [PMID: 31001776 DOI: 10.1007/s11356-019-04974-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 03/22/2019] [Indexed: 06/09/2023]
Abstract
Mercury (Hg), the environmental toxicant, is present in the soil, water, and air as it is substantially distributed throughout the environment. Being extremely toxic even at low concentration, its remediation is utterly important. Therefore, it is necessary to detoxify the contaminant within the acceptable limits before threatening the environment. Although various conventional methods are being used, irrespective of high cost, it produces intermediate toxic by-product too. Biological methods are eco-friendly, clean, greener, and safer for the remediation of heavy metals corresponding to the conventional remediation due to their economic and high-tech constraints. Bioremediation is now being used for Hg (II) removal, which involves biosorption and bioaccumulation mechanisms or both, also mercuric ion reductase, exopolysaccharide play significant role in detoxification of mercury by acting a potential instrument for the remediation of heavy metals. In this review paper, we shed light on problems caused by mercury pollution, mercury cycle, and its global scenario and detoxification approaches by biological methods and result found in the literature.
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Affiliation(s)
- Shalini Singh
- Laboratory of Applied Microbiology, Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand, 826 004, India
| | - Vipin Kumar
- Laboratory of Applied Microbiology, Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand, 826 004, India.
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119
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Song Y, Adediran GA, Jiang T, Hayama S, Björn E, Skyllberg U. Toward an Internally Consistent Model for Hg(II) Chemical Speciation Calculations in Bacterium-Natural Organic Matter-Low Molecular Mass Thiol Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:8094-8103. [PMID: 32491838 PMCID: PMC7467648 DOI: 10.1021/acs.est.0c01751] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
To advance the scientific understanding of bacteria-driven mercury (Hg) transformation processes in natural environments, thermodynamics and kinetics of divalent mercury Hg(II) chemical speciation need to be understood. Based on Hg LIII-edge extended X-ray absorption fine structure (EXAFS) spectroscopic information, combined with competitive ligand exchange (CLE) experiments, we determined Hg(II) structures and thermodynamic constants for Hg(II) complexes formed with thiol functional groups in bacterial cell membranes of two extensively studied Hg(II) methylating bacteria: Geobacter sulfurreducens PCA and Desulfovibrio desulfuricans ND132. The Hg EXAFS data suggest that 5% of the total number of membranethiol functionalities (Mem-RStot = 380 ± 50 μmol g-1 C) are situated closely enough to be involved in a 2-coordinated Hg(Mem-RS)2 structure in Geobacter. The remaining 95% of Mem-RSH is involved in mixed-ligation Hg(II)-complexes, combining either with low molecular mass (LMM) thiols like Cys, Hg(Cys)(Mem-RS), or with neighboring O/N membrane functionalities, Hg(Mem-RSRO). We report log K values for the formation of the structures Hg(Mem-RS)2, Hg(Cys)(Mem-RS), and Hg(Mem-RSRO) to be 39.1 ± 0.2, 38.1 ± 0.1, and 25.6 ± 0.1, respectively, for Geobacter and 39.2 ± 0.2, 38.2 ± 0.1, and 25.7 ± 0.1, respectively, for ND132. Combined with results obtained from previous studies using the same methodology to determine chemical speciation of Hg(II) in the presence of natural organic matter (NOM; Suwannee River DOM) and 15 LMM thiols, an internally consistent thermodynamic data set is created, which we recommend to be used in studies of Hg transformation processes in bacterium-NOM-LMM thiol systems.
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Affiliation(s)
- Yu Song
- Department
of Forest Ecology and Management, Swedish
University of Agricultural Science, SE-901 83 Umeå, Sweden
| | | | - Tao Jiang
- Department
of Forest Ecology and Management, Swedish
University of Agricultural Science, SE-901 83 Umeå, Sweden
| | - Shusaku Hayama
- Diamond
Light Source, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Erik Björn
- Department
of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
| | - Ulf Skyllberg
- Department
of Forest Ecology and Management, Swedish
University of Agricultural Science, SE-901 83 Umeå, Sweden
- . Phone: +46 (0)90-786 84 60
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120
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Zhou XQ, Hao YY, Gu B, Feng J, Liu YR, Huang Q. Microbial Communities Associated with Methylmercury Degradation in Paddy Soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:7952-7960. [PMID: 32437137 DOI: 10.1021/acs.est.0c00181] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Bioaccumulation of the neurotoxin methylmercury (MeHg) in rice has raised worldwide concerns because of its risks to human health. Certain microorganisms are able to degrade MeHg in pure cultures, but the roles and diversities of the microbial communities in MeHg degradation in rice paddy soils are unknown. Using a series of microcosms, we investigated MeHg degradation in paddy soils from Hunan, Guizhou, and Hubei provinces, representing three major rice production regions in China, and further characterized one of the soils from the Hunan Province for microbial communities associated with MeHg degradation. Microbial demethylation was observed in all three soils, demonstrated by significantly more MeHg degraded in the unsterilized soils than in the sterilized controls. More demethylation occurred in water-saturated soils than in unsaturated soils, but the addition of molybdate and bromoethanesulfonic acid as the respective inhibitors of sulfate reducing bacteria and methanogens showed insignificant effects on MeHg degradation. However, the addition of Cu enhanced MeHg degradation and the enrichment of Xanthomonadaceae in the unsaturated soil. 16S rRNA Illumina sequencing and metatranscriptomic analyses of the Hunan soil consistently revealed that Catenulisporaceae, Frankiaceae, Mycobacteriaceae, and Thermomonosporaceae were among the most likely microbial taxa in influencing MeHg degradation in the paddy soil, and they were confirmed by combined analyses of the co-occurrence network, random forest modeling, and linear discriminant analysis of the effect size. Our results shed additional light onto the roles of microbial communities in MeHg degradation in paddy soils and its subsequent bioaccumulation in rice grains.
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Affiliation(s)
- Xin-Quan Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Yun-Yun Hao
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Baohua Gu
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jiao Feng
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Yu-Rong Liu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Key Laboratory of Soil Environment and Pollution Remediation, Wuhan 430070, China
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Key Laboratory of Soil Environment and Pollution Remediation, Wuhan 430070, China
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121
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Tada Y, Marumoto K, Takeuchi A. Nitrospina-Like Bacteria Are Potential Mercury Methylators in the Mesopelagic Zone in the East China Sea. Front Microbiol 2020; 11:1369. [PMID: 32719662 PMCID: PMC7347909 DOI: 10.3389/fmicb.2020.01369] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 05/27/2020] [Indexed: 11/18/2022] Open
Abstract
In natural environments, the production of neurotoxic and bioaccumulative methylmercury (MeHg) is mediated by microorganisms carrying the genes hgcA and hgcB. However, the contribution of these microorganisms to mercury (Hg) methylation or MeHg accumulation in the ocean is poorly understood. Here we determined the total Hg (THg) and MeHg concentrations in seawater samples and conducted a metagenomic survey of the hgcAB genes and functional modules involved in metabolic pathways in the East China Sea (ECS). In the metagenomic analyses, we used paired-end reads and assembled contigs for hgcAB enumeration and phylogenetic analyses in the seawater column. To evaluate the relative abundance of hgcAB in the metagenomic data, we estimated the abundance of recA (single-copy gene of bacteria) as well and then compared them. Moreover, the profiles of prokaryotic community composition were analyzed by 16S rRNA gene (V4 region) deep-sequencing. In the mesopelagic layers, the hgcA sequences were detected, and there was a positive correlation between hgcA abundance relative to the recA and MeHg concentrations. Thus, the quantification of the hgcA sequences could provide valuable information to evaluate the potential environments of microbial MeHg accumulation in the seawater column. A phylogenetic analysis using the assembled contigs revealed that all of the hgcA sequences in the mesopelagic layers were affiliated with Nitrospina-like sequences. The 16S rRNA gene analysis revealed that Nitrospinae were abundant in the mesopelagic layers. Although the lineages of Deltaproteobacteria, Firmicutes, and Spirochaetes were detected in the seawater column, their hgcAB sequences were not detected in our metagenomes, despite the fact that they are closely related to previously identified Hg methylators. The metabolic pathway analysis revealed that the modules related to sulfur and methane metabolism were prominent in the mesopelagic layers. However, no hgcA sequences affiliated with sulfate-reducing bacteria (SRB) or methanogens were detected in these layers, suggesting that these bacteria could not be strongly involved in the Hg accumulation in the seawater column. Our results indicate that Nitrospina-like bacteria with hgcAB genes could play a critical role in microbial Hg accumulation in the oxygenated mesopelagic layers of the ECS.
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Affiliation(s)
- Yuya Tada
- Department of Environment and Public Health, National Institute for Minamata Disease, Kumamoto, Japan
| | - Kohji Marumoto
- Department of Environment and Public Health, National Institute for Minamata Disease, Kumamoto, Japan
| | - Akinori Takeuchi
- Center for Environmental Measurement and Analysis, National Institute for Environmental Studies, Ibaraki, Japan
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Cooper CJ, Zheng K, Rush KW, Johs A, Sanders BC, Pavlopoulos GA, Kyrpides NC, Podar M, Ovchinnikov S, Ragsdale SW, Parks JM. Structure determination of the HgcAB complex using metagenome sequence data: insights into microbial mercury methylation. Commun Biol 2020; 3:320. [PMID: 32561885 PMCID: PMC7305189 DOI: 10.1038/s42003-020-1047-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 05/27/2020] [Indexed: 11/09/2022] Open
Abstract
Bacteria and archaea possessing the hgcAB gene pair methylate inorganic mercury (Hg) to form highly toxic methylmercury. HgcA consists of a corrinoid binding domain and a transmembrane domain, and HgcB is a dicluster ferredoxin. However, their detailed structure and function have not been thoroughly characterized. We modeled the HgcAB complex by combining metagenome sequence data mining, coevolution analysis, and Rosetta structure calculations. In addition, we overexpressed HgcA and HgcB in Escherichia coli, confirmed spectroscopically that they bind cobalamin and [4Fe-4S] clusters, respectively, and incorporated these cofactors into the structural model. Surprisingly, the two domains of HgcA do not interact with each other, but HgcB forms extensive contacts with both domains. The model suggests that conserved cysteines in HgcB are involved in shuttling HgII, methylmercury, or both. These findings refine our understanding of the mechanism of Hg methylation and expand the known repertoire of corrinoid methyltransferases in nature. Connor J. Cooper et al. expressed HgcA and HgcB in Escherichia coli and modeled the structure of the HgcAB complex by combining metagenome sequence data, coevolution analysis, and ab initio structure calculations. This study provides insights into the biochemical mechanism of mercury (Hg) methylation.
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Affiliation(s)
- Connor J Cooper
- Graduate School of Genome Science and Technology, University of Tennessee, F225 Walters Life Science, Knoxville, TN, 37996, USA.,Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37831-6038, USA
| | - Kaiyuan Zheng
- Department of Biological Chemistry, University of Michigan Medical School, 1150 West Medical Center Drive, Ann Arbor, MI, 48109-0606, USA
| | - Katherine W Rush
- Department of Biological Chemistry, University of Michigan Medical School, 1150 West Medical Center Drive, Ann Arbor, MI, 48109-0606, USA
| | - Alexander Johs
- Environmental Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37831-6038, USA
| | - Brian C Sanders
- Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37831-6038, USA
| | - Georgios A Pavlopoulos
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA.,Institute for Fundamental Biomedical Research, Biomedical Science Research Center "Alexander Fleming", 34 Fleming Street, 16672, Vari, Greece
| | - Nikos C Kyrpides
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA.,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory Berkeley, California, USA
| | - Mircea Podar
- Graduate School of Genome Science and Technology, University of Tennessee, F225 Walters Life Science, Knoxville, TN, 37996, USA.,Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37831-6038, USA
| | - Sergey Ovchinnikov
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA, 02138, USA
| | - Stephen W Ragsdale
- Department of Biological Chemistry, University of Michigan Medical School, 1150 West Medical Center Drive, Ann Arbor, MI, 48109-0606, USA
| | - Jerry M Parks
- Graduate School of Genome Science and Technology, University of Tennessee, F225 Walters Life Science, Knoxville, TN, 37996, USA. .,Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37831-6038, USA.
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123
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Bourdineaud JP, Durn G, Režun B, Manceau A, Hrenović J. The chemical species of mercury accumulated by Pseudomonas idrijaensis, a bacterium from a rock of the Idrija mercury mine, Slovenia. CHEMOSPHERE 2020; 248:126002. [PMID: 32032872 DOI: 10.1016/j.chemosphere.2020.126002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 01/10/2020] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
A mercury-resistant bacterial strain has been isolated from a rock of the Idrija mercury mine in Slovenia. The rock had 19 g carbon and 2952 mg mercury (Hg) per kg. Mass spectrometry and DNA sequencing showed that the bacterium belongs to the Pseudomonas genus. It is called Pseudomonas idrijaensis. This bacterial strain is sensitive to methylmercury (MeHg) like the reference P. aeruginosa strain PAO1, and is resistant to divalent mercury (Hg(II)) in contrast to PAO1. This difference could be attributed to the presence of the mer operon yet deprived of the merB gene encoding the organomercurial lyase, on the basis of whole genome sequencing. The P. idrijaensis mer operon displays the RTPCADE organization and is contained in the Tn5041 transposon. This transposon identified here occurs in other Gram-negative Hg-resistant strains isolated from mercury ores, aquatic systems and soils, including Pseudomonas strains from 15,000 to 40,000 years old Siberian permafrost. When P. idrijaensis was exposed to mercury chloride, two intracellular Hg species were identified by high energy-resolution XANES spectroscopy, a dithiolate Hg(SR)2 and a tetrathiolate Hg(SR)4 complex. P. idrijaensis had a much higher [Hg(SR)2]/[Hg(SR)4] molar ratio than bacteria lacking the mer operon when exposed to 4 μg Hg2+/L - resulting in an intracellular accumulation of 4.3 μg Hg/g dw. A higher amount of the Hg(SR)2 complex provides a chemical signature for the expression of the dicysteinate Mer proteins in response to mercury toxicity.
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Affiliation(s)
- Jean-Paul Bourdineaud
- University of Bordeaux, CNRS, Fundamental Microbiology and Pathogenicity Laboratory, European Institute of Chemistry and Biology, 2 Rue Robert Escarpit, 33607, Pessac, France.
| | - Goran Durn
- University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering, Croatia.
| | - Bojan Režun
- Idrija UNESCO Global Geopark, Lapajnetova 1A 5280, Idrija, Slovenia.
| | - Alain Manceau
- University Grenoble Alpes, CNRS, ISTerre, 38000, Grenoble, France.
| | - Jasna Hrenović
- University of Zagreb, Faculty of Science, Department of Biology, Zagreb, Croatia.
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Synergistic Effects of a Chalkophore, Methanobactin, on Microbial Methylation of Mercury. Appl Environ Microbiol 2020; 86:AEM.00122-20. [PMID: 32220843 DOI: 10.1128/aem.00122-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 03/24/2020] [Indexed: 11/20/2022] Open
Abstract
Microbial production of the neurotoxin methylmercury (MeHg) is a significant health and environmental concern, as it can bioaccumulate and biomagnify in the food web. A chalkophore or a copper-binding compound, termed methanobactin (MB), has been shown to form strong complexes with mercury [as Hg(II)] and also enables some methanotrophs to degrade MeHg. It is unknown, however, if Hg(II) binding with MB can also impede Hg(II) methylation by other microbes. Contrary to expectations, MB produced by the methanotroph Methylosinus trichosporium OB3b (OB3b-MB) enhanced the rate and efficiency of Hg(II) methylation more than that observed with thiol compounds (such as cysteine) by the mercury-methylating bacteria Desulfovibrio desulfuricans ND132 and Geobacter sulfurreducens PCA. Compared to no-MB controls, OB3b-MB decreased the rates of Hg(II) sorption and internalization, but increased methylation by 5- to 7-fold, suggesting that Hg(II) complexation with OB3b-MB facilitated exchange and internal transfer of Hg(II) to the HgcAB proteins required for methylation. Conversely, addition of excess amounts of OB3b-MB or a different form of MB from Methylocystis strain SB2 (SB2-MB) inhibited Hg(II) methylation, likely due to greater binding of Hg(II). Collectively, our results underscore the complex roles of microbial exogenous metal-scavenging compounds in controlling net production and bioaccumulation of MeHg in the environment.IMPORTANCE Some anaerobic microorganisms convert inorganic mercury (Hg) into the neurotoxin methylmercury, which can bioaccumulate and biomagnify in the food web. While the genetic basis of microbial mercury methylation is known, factors that control net methylmercury production in the environment are still poorly understood. Here, it is shown that mercury methylation can be substantially enhanced by one form of an exogenous copper-binding compound (methanobactin) produced by some methanotrophs, but not by another. This novel finding illustrates that complex interactions exist between microbes and that these interactions can potentially affect the net production of methylmercury in situ.
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125
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Mendoza JI, Soncini FC, Checa SK. Engineering of a Au-sensor to develop a Hg-specific, sensitive and robust whole-cell biosensor for on-site water monitoring. Chem Commun (Camb) 2020; 56:6590-6593. [PMID: 32406434 DOI: 10.1039/d0cc01323d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A highly sensitive and specific Hg-whole-cell biosensor was developed from a non-selective variant of the Au sensor GolS and its regulatory pathway. The performance of this analytical tool was validated under laboratory and field-like conditions. This biosensor can be easily applied in cost-effective and portable semiquantitative devices to report Hg contamination in water.
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Affiliation(s)
- Julián I Mendoza
- Instituto de Biología Molecular y Celular de Rosario (IBR), Universidad Nacional de Rosario (UNR)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Rosario, Argentina.
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126
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Bravo AG, Cosio C. Biotic formation of methylmercury: A bio-physico-chemical conundrum. LIMNOLOGY AND OCEANOGRAPHY 2020; 65:1010-1027. [PMID: 32612306 PMCID: PMC7319479 DOI: 10.1002/lno.11366] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 09/17/2019] [Accepted: 10/02/2019] [Indexed: 05/11/2023]
Abstract
Mercury (Hg) is a natural and widespread trace metal, but is considered a priority pollutant, particularly its organic form methylmercury (MMHg), because of human's exposure to MMHg through fish consumption. Pioneering studies showed the methylation of divalent Hg (HgII) to MMHg to occur under oxygen-limited conditions and to depend on the activity of anaerobic microorganisms. Recent studies identified the hgcAB gene cluster in microorganisms with the capacity to methylate HgII and unveiled a much wider range of species and environmental conditions producing MMHg than previously expected. Here, we review the recent knowledge and approaches used to understand HgII-methylation, microbial biodiversity and activity involved in these processes, and we highlight the current limits for predicting MMHg concentrations in the environment. The available data unveil the fact that HgII methylation is a bio-physico-chemical conundrum in which the efficiency of biological HgII methylation appears to depend chiefly on HgII and nutrients availability, the abundance of electron acceptors such as sulfate or iron, the abundance and composition of organic matter as well as the activity and structure of the microbial community. An increased knowledge of the relationship between microbial community composition, physico-chemical conditions, MMHg production, and demethylation is necessary to predict variability in MMHg concentrations across environments.
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Affiliation(s)
- Andrea G. Bravo
- Department of Marine Biology and Oceanography, Institute of Marine SciencesSpanish National Research Council (CSIC)BarcelonaSpain
| | - Claudia Cosio
- Université de Reims Champagne Ardennes, UMR‐I 02 INERIS‐URCA‐ULH SEBIO, Unité Stress Environnementaux et BIOsurveillance des milieux aquatiquesReimsFrance
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127
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Recent developments in environmental mercury bioremediation and its toxicity: A review. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.enmm.2020.100283] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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128
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Mariano C, Mello IS, Barros BM, da Silva GF, Terezo AJ, Soares MA. Mercury alters the rhizobacterial community in Brazilian wetlands and it can be bioremediated by the plant-bacteria association. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:13550-13564. [PMID: 32030584 DOI: 10.1007/s11356-020-07913-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/28/2020] [Indexed: 06/10/2023]
Abstract
This study examined how soil mercury contamination affected the structure and functionality of rhizobacteria communities from Aeschynomene fluminensis and Polygonum acuminatum and how rhizobacteria mediate metal bioremediation. The strains were isolated using culture-dependent methods, identified through 16S rDNA gene sequencing, and characterized with respect to their functional traits related to plant growth promotion and resistance to metals and antibiotics. The bioremediation capacity of the rhizobacteria was determined in greenhouse using corn plants. The isolated bacteria belonged to the phyla Actinobacteria, Deinococcus-Thermus, Firmicutes, and Proteobacteria, with great abundance of the species Microbacterium trichothecenolyticum. The rhizobacteria abundance, richness, and diversity were greater in mercury-contaminated soils. Bacteria isolated from contaminated environments had higher minimum inhibitory concentration values, presented plasmids and the merA gene, and were multi-resistant to metals and antibiotics. Enterobacter sp._C35 and M. trichothecenolyticum_C34 significantly improved (Dunnett's test, p < 0.05) corn plant growth in mercury-contaminated soil. These bacteria helped to reduce up to 87% of the mercury content in the soil, and increased the mercury bioaccumulation factor by up to 94%. Mercury bioremediation mitigated toxicity of the contaminated substrate. Enterobacter sp._C35, Bacillus megaterium_C28, and Bacillus mycoides_C1 stimulated corn plant growth and could be added to biofertilizers produced in research and related industries.
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Affiliation(s)
- Caylla Mariano
- Laboratory of Biotechnology and Microbial Ecology, Institute of Biosciences, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Ivani Souza Mello
- Laboratory of Biotechnology and Microbial Ecology, Institute of Biosciences, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Breno Martins Barros
- Laboratory of Biotechnology and Microbial Ecology, Institute of Biosciences, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | | | - Ailton Jose Terezo
- Central Analytical of Fuels, Department of Chemistry, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Marcos Antônio Soares
- Laboratory of Biotechnology and Microbial Ecology, Institute of Biosciences, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil.
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129
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Shahid M, Khalid S, Bibi I, Bundschuh J, Khan Niazi N, Dumat C. A critical review of mercury speciation, bioavailability, toxicity and detoxification in soil-plant environment: Ecotoxicology and health risk assessment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 711:134749. [PMID: 32000322 DOI: 10.1016/j.scitotenv.2019.134749] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/18/2019] [Accepted: 09/29/2019] [Indexed: 05/09/2023]
Abstract
Environmental contamination by a non-essential and non-beneficial, although potentially toxic mercury (Hg), is becoming a great threat to the living organisms at a global scale. Owing to its various uses in numerous industrial processes, high amount of Hg is released into different environmental compartments. Environmental Hg contamination can result in food chain contamination, especially due to its accumulation in edible plant parts. Consumption of Hg-rich food is a key source of Hg exposure to humans. Since Hg does not possess any identified biological role and has genotoxic and carcinogenic potential, it is critical to monitor its biogeochemical behavior in the soil-plant system and its influence in terms of possible food chain contamination and human exposure. This review traces a plausible link among Hg levels, its chemical speciation and phytoavailability in soil, accumulation in plants, phytotoxicity and detoxification of Hg inside the plant. The role of different enzymatic (peroxidase, catalase, ascorbate peroxidase, superoxide dismutase, glutathione peroxidase) and non-enzymatic (glutathione, phytochelatins, proline and ascorbic acid) antioxidants has also been elucidated with respect to enhanced generation of reactive radicles and resulting oxidative stress. The review also outlines Hg build-up in edible plant tissues and associated health risks. The biogeochemical role of Hg in the soil-plant system and associated health risks have been described with well summarized and up-to-date data in 12 tables and 4 figures. We believe that this comprehensive review article and meta-analysis of Hg data can be greatly valuable for scientists, researchers, policymakers and graduate-level students.
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Affiliation(s)
- Muhammad Shahid
- Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus, Vehari-61100, Pakistan.
| | - Sana Khalid
- Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus, Vehari-61100, Pakistan
| | - Irshad Bibi
- Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Faisalabad 38040, Pakistan
| | - Jochen Bundschuh
- UNESCO Chair on Groundwater Arsenic within the 2030 Agenda for Sustainable Development, University of Southern Queensland, West Street, Toowoomba, Queensland 4350, Australia
| | - Nabeel Khan Niazi
- Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Faisalabad 38040, Pakistan; School of Civil Engineering and Surveying, University of Southern Queensland, Toowoomba, Queensland, Australia.
| | - Camille Dumat
- Centre d'Etude et de Recherche Travail Organisation Pouvoir (CERTOP), UMR5044, Université J. Jaurès - Toulouse II, 5 allée Machado A., 31058 Toulouse, cedex 9, France; Université de Toulouse, INP-ENSAT, Avenue de l'Agrobiopole, 31326 Auzeville-Tolosane, France; Association Réseau-Agriville (http://reseau-agriville.com/), France
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130
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Hwang H, Hazel A, Lian P, Smith JC, Gumbart JC, Parks JM. A Minimal Membrane Metal Transport System: Dynamics and Energetics of mer Proteins. J Comput Chem 2020; 41:528-537. [PMID: 31721253 PMCID: PMC7263448 DOI: 10.1002/jcc.26098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/17/2019] [Accepted: 10/14/2019] [Indexed: 12/28/2022]
Abstract
The mer operon in bacteria encodes a set of proteins and enzymes that impart resistance to environmental mercury toxicity by importing Hg2+ and reducing it to volatile Hg(0). Because the reduction occurs in the cytoplasm, mercuric ions must first be transported across the cytoplasmic membrane by one of a few known transporters. MerF is the smallest of these, containing only two transmembrane helices and two pairs of vicinal cysteines that coordinate mercuric ions. In this work, we use molecular dynamics simulations to characterize the dynamics of MerF in its apo and Hg2+ -bound states. We find that the apo state positions one of the cysteine pairs closer to the periplasmic side of the membrane, while in the bound state the same pair approaches the cytoplasmic side. This finding is consistent with the functional requirement of accepting Hg2+ from the periplasmic space, sequestering it on acceptance, and transferring it to the cytoplasm. Conformational changes in the TM helices facilitate the functional interaction of the two cysteine pairs. Free-energy calculations provide a barrier of 16 kcal/mol for the association of the periplasmic Hg2+ -bound protein MerP with MerF and 7 kcal/mol for the subsequent association of MerF's two cysteine pairs. Despite the significant conformational changes required to move the binding site across the membrane, coarse-grained simulations of multiple copies of MerF support the expectation that it functions as a monomer. Our results demonstrate how conformational changes and binding thermodynamics could lead to such a small membrane protein acting as an ion transporter. Published 2019. This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Hyea Hwang
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
| | - Anthony Hazel
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - Peng Lian
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, 37996
| | - Jeremy C. Smith
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996
| | - James C. Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - Jerry M. Parks
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
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131
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Norambuena J, Miller M, Boyd JM, Barkay T. Expression and regulation of the mer operon in Thermus thermophilus. Environ Microbiol 2020; 22:1619-1634. [PMID: 32090420 DOI: 10.1111/1462-2920.14953] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 01/16/2020] [Indexed: 11/25/2022]
Abstract
Mercury (Hg) is a highly toxic and widely distributed heavy metal, which some Bacteria and Archaea detoxify by the reduction of ionic Hg (Hg[II]) to the elemental volatile form, Hg(0). This activity is specified by the mer operon. The mer operon of the deeply branching thermophile Thermus thermophilus HB27 encodes for, an O-acetyl-l-homoacetylserine sulfhydrylase (Oah2), a transcriptional regulator (MerR), a hypothetical protein (hp) and a mercuric reductase (MerA). Here, we show that this operon has two convergently expressed and differentially regulated promoters. An upstream promoter, P oah , controls the constitutive transcription of the entire operon and a second promoter (P mer ), located within merR, is responsive to Hg(II). In the absence of Hg(II), the transcription of merA is basal and when Hg(II) is present, merA transcription is induced. This response to Hg(II) is controlled by MerR and genetic evidence suggests that MerR acts as a repressor and activator of P mer . When the whole merR, including P mer , is removed, merA is transcribed from P oah independently of Hg(II). These results suggest that the transcriptional regulation of mer in T. thermophilus is both similar to, and different from, the well-documented regulation of proteobacterial mer systems, possibly representing an early step in the evolution of mer-operon regulation.
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Affiliation(s)
- Javiera Norambuena
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, 08901, New Jersey, USA
| | - Maximilian Miller
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, 08901, New Jersey, USA
| | - Jeffrey M Boyd
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, 08901, New Jersey, USA
| | - Tamar Barkay
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, 08901, New Jersey, USA
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132
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Matsumoto M, Liu H. Mercury speciation and remediation strategies at a historically elemental mercury spilled site. JOURNAL OF HAZARDOUS MATERIALS 2020; 384:121351. [PMID: 31600697 DOI: 10.1016/j.jhazmat.2019.121351] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 09/25/2019] [Accepted: 09/28/2019] [Indexed: 06/10/2023]
Abstract
This study quantified the mercury speciation in a contaminated area three decades after an elemental mercury spill from a sodium nuclear reactor experiment, and evaluated ex situ and in situ remediation strategies. Soil samples were taken across multiple sites with different soil depths. A majority of total mercury was distributed in surface soils with depths between 0-0.5 m, and decreased exponentially with depths. In top soils with depths between 0-0.5 m, a considerable fraction of mercury exists in chemical forms that are highly mobile (i.e., bound to inorganic ions) or potential mobile (i.e., bound to soil humic substances). This suggests that bioremediation and phytoremediation may be effective to remove mercury in the top soils at contaminated sites. In deep soils below 1 m, mercury predominantly exists as elemental form that is tightly bound to soil particles. While this fraction of mercury poses no immediate health risk, in situ thermal treatment may be evaluated to remove this mercury fraction. Furthermore, size fractionation data suggest that as an ex situ excavation cleanup option, reducing the volume of contaminated soils is possible by only selecting the sand and gravel size fractions of soil for offsite treatment.
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Affiliation(s)
- Mark Matsumoto
- School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Haizhou Liu
- Department of Chemical and Environmental Engineering, University of California at Riverside, Riverside, CA 92521, USA.
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133
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Pathak A, Jaswal R, Chauhan A. Genomic Characterization of a Mercury Resistant Arthrobacter sp. H-02-3 Reveals the Presence of Heavy Metal and Antibiotic Resistance Determinants. Front Microbiol 2020; 10:3039. [PMID: 32010097 PMCID: PMC6978705 DOI: 10.3389/fmicb.2019.03039] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 12/17/2019] [Indexed: 11/18/2022] Open
Abstract
Nuclear production and industrial activities led to widespread contamination of the Department of Energy (DOE) managed Savannah River Site (SRS), located in South Carolina, United States. The H-02 wetland system was constructed in 2007 for the treatment of industrial and storm water runoff from the SRS Tritium Facility. Albeit at low levels, mercury (Hg) has been detected in the soils of the H-02 wetland ecosystem. In anoxic sediments, Hg is typically methylated by anaerobic microbiota, forming the highly neurotoxic methylmercury (MeHg), which biomagnifies across food webs. However, in surficial oxic wetland soils, microbially mediated demethylation and/or volatilization processes can transform Hg2+ into the less toxic Hg0 form which is released into the atmosphere, thus circumventing MeHg formation. To obtain a deeper understanding on bacterial Hg volatilization, a robust Hg-resistant (HgR) bacteria, called as strain H-02-3 was isolated from the H-02 soils. A draft genome sequence of this strain was obtained at a coverage of 700×, which assembled in 44 contigs with an N50 of 171,569 bp. The genomic size of the strain H-02-3 was 4,708,612 bp with a total number of 4,240 genes; phylogenomic analysis revealed the strain as an Arthrobacter species. Comparative genomics revealed the presence of 1100 unique genes in strain H-02-3, representing 26.7% of the total genome; many identified previously as metal resistance genes (MRGs). Specific to Hg-cycling, the presence of mercuric ion reductase (merA), the organomercurial lyase (merB), and the mercuric resistance operon regulatory protein, were identified. By inference, it can be proposed that the organomercurial lyase facilitates the demethylation of MeHg into Hg2+ which is then reduced to Hg0 by MerA in strain H-02-3. Furthermore, gene prediction using resistome analysis of strain H-02-3 revealed the presence of several antibiotic resistance genes (ARGs), that statistically correlated with the presence of metal resistant genes (MRGs), suggesting co-occurrence patterns of MRGs and ARGs in the strain. Overall, this study delineates environmentally beneficial traits that likely facilitates survival of Arthrobacter sp. H-02-3 within the H-02 wetland soil. Finally, this study also highlights the largely ignored public health risk associated with the co-development of ARGs and MRGs in bacteria native to historically contaminated soils.
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Affiliation(s)
- Ashish Pathak
- Environmental Biotechnology Laboratory, School of the Environment, FSH Science Research Center, Florida A&M University, Tallahassee, FL, United States
| | - Rajneesh Jaswal
- Environmental Biotechnology Laboratory, School of the Environment, FSH Science Research Center, Florida A&M University, Tallahassee, FL, United States
| | - Ashvini Chauhan
- Environmental Biotechnology Laboratory, School of the Environment, FSH Science Research Center, Florida A&M University, Tallahassee, FL, United States
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134
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Giovanella P, Vieira GAL, Ramos Otero IV, Pais Pellizzer E, de Jesus Fontes B, Sette LD. Metal and organic pollutants bioremediation by extremophile microorganisms. JOURNAL OF HAZARDOUS MATERIALS 2020; 382:121024. [PMID: 31541933 DOI: 10.1016/j.jhazmat.2019.121024] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 07/17/2019] [Accepted: 08/14/2019] [Indexed: 06/10/2023]
Abstract
Extremophiles comprise microorganisms that are able to grow and thrive in extreme environments, including in an acidic or alkaline pH, high or low temperatures, high concentrations of pollutants, and salts, among others. These organisms are promising for environmental biotechnology due to their unique physiological and enzymatic characteristics, which allow them to survive in harsh environments. Due to the stability and persistence of these microorganisms under adverse environmental conditions, they can be used for the bioremediation of environments contaminated with extremely recalcitrant pollutants. Here, we provide an overview of extremophiles and the role of "omics" in the field of bioremediation of environmental pollutants, including hydrocarbons, textile dyes and metals.
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Affiliation(s)
- Patricia Giovanella
- Departamento de Bioquímica e Microbiologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, SP, Brazil.
| | - Gabriela A L Vieira
- Departamento de Bioquímica e Microbiologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, SP, Brazil
| | - Igor V Ramos Otero
- Departamento de Bioquímica e Microbiologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, SP, Brazil
| | - Elisa Pais Pellizzer
- Departamento de Bioquímica e Microbiologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, SP, Brazil
| | - Bruno de Jesus Fontes
- Departamento de Bioquímica e Microbiologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, SP, Brazil
| | - Lara D Sette
- Departamento de Bioquímica e Microbiologia, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, SP, Brazil.
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135
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Micciche AC, Barabote RD, Dittoe DK, Ricke SC. In silico genome analysis of an acid mine drainage species, Acidiphilium multivorum, for potential commercial acetic acid production and biomining. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2020; 55:447-454. [PMID: 31941390 DOI: 10.1080/03601234.2019.1710985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The genome of Acidiphilium multivorum strain AIU 301, acidophilic, aerobic Gram-negative bacteria, was investigated for potential metabolic pathways associated with organic acid production and metal uptake. The genome was compared to other acidic mine drainage isolates, Acidiphilium cryptum JF-5 and Acidithiobacillus ferrooxidans ATCC 23270, as well as Acetobacter pasteurianus 386B, which ferments cocoa beans. Plasmids between two Acidiphilium spp. were compared, and only two of the sixteen plasmids were identified as potentially similar. Comparisons of the genome size to the number of protein coding sequences indicated that A. multivorum and A. cryptum follow the line of best fit unlike A. pasteurianus 386B, which suggests that it was improperly annotated in the database. Pathways between these four species were analyzed bioinformatically and are discussed here. A. multivorum AIU 301, shares pathways with A. pasteurianus 386B including aldehyde and alcohol dehydrogenase pathways, which are used in the generation of vinegar. Mercury reductase, arsenate reductase and sulfur utilization proteins were identified and discussed at length. The absence of sulfur utilization proteins from A. multivorum AIU 301 suggests that this species uses previously undefined pathways for sulfur acquisition. Bioinformatic examination revealed novel pathways that may benefit commercial fields including acetic acid production and biomining.
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Affiliation(s)
- A C Micciche
- Department of Food Science, Center for Food Safety, University of Arkansas, Fayetteville, Arkansas, USA
| | - R D Barabote
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas, USA
| | - D K Dittoe
- Department of Food Science, Center for Food Safety, University of Arkansas, Fayetteville, Arkansas, USA
| | - S C Ricke
- Department of Food Science, Center for Food Safety, University of Arkansas, Fayetteville, Arkansas, USA
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136
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Lavoie NC, Grégoire DS, Stenzler BR, Poulain AJ. Reduced sulphur sources favour Hg II reduction during anoxygenic photosynthesis by Heliobacteria. GEOBIOLOGY 2020; 18:70-79. [PMID: 31536173 DOI: 10.1111/gbi.12364] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 08/16/2019] [Accepted: 08/31/2019] [Indexed: 06/10/2023]
Abstract
The consumption of rice has become a global food safety issue because rice paddies support the production of high levels of the potent neurotoxin, methylmercury. The production of methylmercury is carried out by chemotrophic anaerobes that rely on a diversity of terminal electron acceptors, namely sulphate. Sulphur can be a limiting nutrient in rice paddies, and sulphate amendments are often used to stimulate crop production, which can increase methylmercury production. Mercury (Hg) redox cycling can affect Hg methylation by controlling the delivery of inorganic Hg substrates to methylators in anoxic habitats. Whereas sulphur is recognized as a key substrate controlling methylmercury production, the controls sulphur exerts on other microbe-mediated Hg transformations remain poorly understood. To explore the potential coupling between sulphur assimilation and anaerobic HgII reduction to Hg0 , we studied Heliobacillus mobilis, a mesophilic anoxygenic phototroph representative from the Heliobacteriacea family originally isolated from a rice paddy. Here, we tested whether the redox state of the sulphur sources available to H. mobilis would affect its ability to reduce HgII . By comparing Hg0 production over a redox gradient of sulphur sources, we demonstrate that phototrophic HgII reduction is favoured in the presence of reduced sulphur sources such as thiosulphate and cysteine. We also show that cysteine exerts dynamic control on Hg cycling by affecting not only Hg's bioavailability but also its abiotic photoreduction under low light conditions. Specifically, in the absence of cells we show that organic matter (as yeast extract) and cysteine are both required for photoreduction to occur. This study offers insights into how one of the most primitive forms of photosynthesis affects Hg redox transformations and frames Heliobacteria as key players in Hg cycling within paddy soils, forming a basis for management strategies to mitigate Hg accumulation in rice.
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Affiliation(s)
- Noémie C Lavoie
- Department of Biology, Faculty of Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Daniel S Grégoire
- Department of Biology, Faculty of Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Bejamin R Stenzler
- Department of Biology, Faculty of Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Alexandre J Poulain
- Department of Biology, Faculty of Sciences, University of Ottawa, Ottawa, Ontario, Canada
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137
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Wang L, Hou D, Cao Y, Ok YS, Tack FMG, Rinklebe J, O'Connor D. Remediation of mercury contaminated soil, water, and air: A review of emerging materials and innovative technologies. ENVIRONMENT INTERNATIONAL 2020; 134:105281. [PMID: 31726360 DOI: 10.1016/j.envint.2019.105281] [Citation(s) in RCA: 146] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/23/2019] [Accepted: 10/20/2019] [Indexed: 05/24/2023]
Abstract
Mercury contamination in soil, water and air is associated with potential toxicity to humans and ecosystems. Industrial activities such as coal combustion have led to increased mercury (Hg) concentrations in different environmental media. This review critically evaluates recent developments in technological approaches for the remediation of Hg contaminated soil, water and air, with a focus on emerging materials and innovative technologies. Extensive research on various nanomaterials, such as carbon nanotubes (CNTs), nanosheets and magnetic nanocomposites, for mercury removal are investigated. This paper also examines other emerging materials and their characteristics, including graphene, biochar, metal organic frameworks (MOFs), covalent organic frameworks (COFs), layered double hydroxides (LDHs) as well as other materials such as clay minerals and manganese oxides. Based on approaches including adsorption/desorption, oxidation/reduction and stabilization/containment, the performances of innovative technologies with the aid of these materials were examined. In addition, technologies involving organisms, such as phytoremediation, algae-based mercury removal, microbial reduction and constructed wetlands, were also reviewed, and the role of organisms, especially microorganisms, in these techniques are illustrated.
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Affiliation(s)
- Liuwei Wang
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Deyi Hou
- School of Environment, Tsinghua University, Beijing 100084, China.
| | - Yining Cao
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Yong Sik Ok
- Korea Biochar Research Center & Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Filip M G Tack
- Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, Wuppertal 42285, Germany; Department of Environment, Energy and Geoinformatics, Sejong University, 98 Gunja-Dong, Seoul, Republic of Korea
| | - David O'Connor
- School of Environment, Tsinghua University, Beijing 100084, China
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Sharma Ghimire P, Tripathee L, Zhang Q, Guo J, Ram K, Huang J, Sharma CM, Kang S. Microbial mercury methylation in the cryosphere: Progress and prospects. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 697:134150. [PMID: 32380618 DOI: 10.1016/j.scitotenv.2019.134150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 08/20/2019] [Accepted: 08/26/2019] [Indexed: 06/11/2023]
Abstract
Mercury (Hg) is one of the most toxic heavy metals, and its cycle is mainly controlled by oxidation-reduction reactions carried out by photochemical or microbial process under suitable conditions. The deposition and accumulation of methylmercury (MeHg) in various ecosystems, including the cryospheric components such as snow, meltwater, glaciers, and ice sheet, and subsequently in the food chain pose serious health concerns for living beings. Unlike the abundance of knowledge about the processes of MeHg production over land and oceans, little is known about the sources and production/degradation rate of MeHg in cryosphere systems. In addition, processes controlling the concentration of Hg and MeHg in the cryosphere remains poorly understood, and filling this scientific gap has been challenging. Therefore, it is essential to study and review the deposition and accumulation by biological, physical, and chemical mechanisms involved in Hg methylation in the cryosphere. This review attempts to address knowledge gaps in understanding processes, especially biotic and abiotic, applicable for Hg methylation in the cryosphere. First, we focus on the variability in Hg concentration and mechanisms of Hg methylation, including physical, chemical, microbial, and biological processes, and transportation in the cryosphere. Then, we elaborate on the mechanism of redox reactions and biotic and abiotic factors controlling Hg methylation and biogeochemistry of Hg in the cryosphere. We also present possible mechanisms of Hg methylation with an emphasis on microbial transformation and molecular function to understand variability in Hg concentration in the cryosphere. Recent advancements in the genetic and physicochemical mechanisms of Hg methylation are also presented. Finally, we summarize and propose a method to study the unsolved issues of Hg methylation in the cryosphere.
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Affiliation(s)
- Prakriti Sharma Ghimire
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal.
| | - Qianggong Zhang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Kirpa Ram
- Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, India
| | - Jie Huang
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Chhatra Mani Sharma
- Himalayan Environment Research Institute (HERI), Kathmandu, Nepal; Central Department of Environmental Science, Tribhuvan University, Kathmandu, Nepal
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China.
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139
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Fong JC, De Guzman BE, Lamborg CH, Sison-Mangus MP. The Mercury-Tolerant Microbiota of the Zooplankton Daphnia Aids in Host Survival and Maintains Fecundity under Mercury Stress. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:14688-14699. [PMID: 31747751 DOI: 10.1021/acs.est.9b05305] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Many aquatic organisms can thrive in polluted environments by having the genetic capability to withstand suboptimal conditions. However, the contributions of microbiomes under these stressful environments are poorly understood. We investigated whether a mercury-tolerant microbiota can extend its phenotype to its host by ameliorating host survival and fecundity under mercury-stress. We isolated microbiota members from various clones of Daphnia magna, screened for the mercury-biotransforming merA gene, and determined their mercury tolerance levels. We then introduced the mercury-tolerant microbiota, Pseudomonas-10, to axenic D. magna and quantified its merA gene expression, mercury reduction capability, and measured its impact on host survival and fecundity. The expression of the merA gene was up-regulated in Pseudomonas-10, both in isolation and in host-association with mercury exposure. Pseudomonas-10 is also capable of significantly reducing mercury concentration in the medium. Notably, mercury-exposed daphnids containing only Pseudomonas-10 exhibited higher survival and fecundity than mercury-exposed daphnids supplemented with parental microbiome. Our study showed that zooplankton, such as Daphnia, naturally harbor microbiome members that are eco-responsive and tolerant to mercury exposure and can aid in host survival and maintain host fecundity in a mercury-contaminated environment. This study further demonstrates that under stressful environmental conditions, the fitness of the host can depend on the genotype and the phenotype of its microbiome.
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Affiliation(s)
- Jiunn C Fong
- Department of Ocean Sciences and Institute for Marine Sciences , University of California Santa Cruz , Santa Cruz , California 95064 , United States
| | - Brandon E De Guzman
- Department of Ocean Sciences and Institute for Marine Sciences , University of California Santa Cruz , Santa Cruz , California 95064 , United States
| | - Carl H Lamborg
- Department of Ocean Sciences and Institute for Marine Sciences , University of California Santa Cruz , Santa Cruz , California 95064 , United States
| | - Marilou P Sison-Mangus
- Department of Ocean Sciences and Institute for Marine Sciences , University of California Santa Cruz , Santa Cruz , California 95064 , United States
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140
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Liu Y, Ji J, Zhang W, Suo Y, Zhao J, Lin X, Cui L, Li B, Hu H, Chen C, Li YF. Selenium modulated gut flora and promoted decomposition of methylmercury in methylmercury-poisoned rats. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 185:109720. [PMID: 31585392 DOI: 10.1016/j.ecoenv.2019.109720] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 09/07/2019] [Accepted: 09/23/2019] [Indexed: 05/28/2023]
Abstract
INTRODUCTION Selenium plays important roles in antagonizing the toxicity of methylmercury. The underlying mechanism for the antagonism between Se and MeHg is still not fully understood. OBJECTIVE The role of gut flora against the toxicity of environmental contaminants is receiving more and more attention. The objective of this study was to investigate the role of Se against MeHg-poisoning in the modulation of gut flora and the decomposition of MeHg. METHODS MeHg-poisoned rats were treated with sodium selenite every other day for 90 days. Fecal samples were collected on Day 8, 30, 60 and 90. Gut flora in feces was determined using 16S rRNA gene profiling, and the concentrations of Se and total mercury (THg) were measured by ICP-MS, and the concentration of MeHg was measured by CVAFS. RESULTS Gut flora at both the ranks of phylum and genus in the MeHg-poisoned rats after Se treatment was modulated towards that in the control group, suggesting the restoration of the profile of gut flora. Increased THg was found in fecal samples after Se treatment on day 30. The percentage of MeHg (of total mercury) in the MeHg-poisoned group was in the range of 81-105% while it was 65-84% in the Se treatment group on different days, suggesting the increased decomposition of MeHg in MeHg-poisoned rats after Se treatment. CONCLUSIONS This study suggests that MeHg poisoning damaged the abundance of gut flora and decreased their capacity for the decomposition of MeHg. After Se treatment, the abundance of gut flora was partially restored and the decomposition and excretion of MeHg was enhanced. These findings suggest that the modulation of gut flora may be one way to promote the health status in MeHg-poisoned rats and possibly in human beings.
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Affiliation(s)
- Yang Liu
- Baotou Medical College, Inner Mongolia University of Science & Technology, Baotou, 014060, Inner Mongolia, China; CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, and HKU-IHEP Joint Laboratory on Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Jun Ji
- Baotou Medical College, Inner Mongolia University of Science & Technology, Baotou, 014060, Inner Mongolia, China
| | - Wei Zhang
- CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, and HKU-IHEP Joint Laboratory on Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China; University of Jinan, No. 336, Nanxinzhuang West Road, Jinan, 250022, Shandong, China
| | - Yao Suo
- Food Science and Engineering College, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jiating Zhao
- CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, and HKU-IHEP Joint Laboratory on Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaoying Lin
- CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, and HKU-IHEP Joint Laboratory on Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Liwei Cui
- CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, and HKU-IHEP Joint Laboratory on Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Bai Li
- CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, and HKU-IHEP Joint Laboratory on Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Huaiqiang Hu
- Department of Neurology, No. 960 Hospital of Chinese PLA, Jinan, 250031, Shandong, China.
| | - Chunying Chen
- CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, National Centre for Nanoscience and Technology, Beijing, 100191, China
| | - Yu-Feng Li
- CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, and HKU-IHEP Joint Laboratory on Metallomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
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141
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Swift evolutionary response of microbes to a rise in anthropogenic mercury in the Northern Hemisphere. ISME JOURNAL 2019; 14:788-800. [PMID: 31831837 PMCID: PMC7031220 DOI: 10.1038/s41396-019-0563-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 11/17/2019] [Indexed: 01/22/2023]
Abstract
Anthropogenic mercury remobilization has considerably increased since the Industrial Revolution in the late 1700s. The Minamata Convention on Mercury is a United Nations treaty (2017) aiming at curbing mercury emissions. Unfortunately, evaluating the effectiveness of such a global treaty is hampered by our inability to determine the lag in aquatic ecosystem responses to a change in atmospheric mercury deposition. Whereas past metal concentrations are obtained from core samples, there are currently no means of tracking historical metal bioavailability or toxicity. Here, we recovered DNA from nine dated sediment cores collected in Canada and Finland, and reconstructed the past demographics of microbes carrying genes coding for the mercuric reductase (MerA)—an enzyme involved in Hg detoxification—using Bayesian relaxed molecular clocks. We found that the evolutionary dynamics of merA exhibited a dramatic increase in effective population size starting from 1783.8 ± 3.9 CE, which coincides with both the Industrial Revolution, and with independent measurements of atmospheric Hg concentrations. We show that even low levels of anthropogenic mercury affected the evolutionary trajectory of microbes in the Northern Hemisphere, and that microbial DNA encoding for detoxification determinants stored in environmental archives can be used to track historical pollutant toxicity.
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142
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Hu H, Li M, Wang G, Drosos M, Li Z, Hu Z, Xi B. Water-soluble mercury induced by organic amendments affected microbial community assemblage in mercury-polluted paddy soil. CHEMOSPHERE 2019; 236:124405. [PMID: 31545202 DOI: 10.1016/j.chemosphere.2019.124405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/17/2019] [Accepted: 07/18/2019] [Indexed: 06/10/2023]
Abstract
Mercury (Hg) pollution or organic amendments (OA) may individually induce changes in the microbial community of paddy soils. However, little is known regarding the interaction of Hg and OA and the effect of different OA applications on the microbial community assemblage in Hg-polluted paddy soil. A soil incubation experiment was performed by applying three organic amendments (OA), namely a food-waste compost (FC), and its HA and FA, into an Hg-polluted paddy soil to examine the changes in the microbial community and merA/merB gene abundance. The results showed that the OA treatments promoted total (SOC) and dissolved organic carbon (DOC) in soils, which may harbor copiotrophic bacteria. The HA and FA treatments decreased microbial diversity and richness along with an increase of water-soluble Hg (WHg) through the complexation of DOC to Hg, which may be mainly attributed to the enhanced Hg biotoxicity to soil microbiome induced by the increased WHg under these two treatments. Additionally, the WHg enhancement also contributed to the increase of Hg-resistant bacteria and merA/merB gene abundance, and consequently, induced changes in the microbial community. These results indicated the interaction of Hg and different OA induced the variation of WHg fraction in paddy soil, which played a fundamental role in the distinct responses of the microbial community assemblage. Collectively, the application of FA and HA to Hg-polluted soil should be limited considering Hg risk to microbiome, and FC can be an alternative.
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Affiliation(s)
- Hualing Hu
- College of Environmental Science and Engineering, Tianjin University, Tianjin, 300035, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Meng Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
| | - Guoxi Wang
- Sino-Danish College, College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Marios Drosos
- Institute of Resource, Ecosystem and Environment of Agriculture, Faculty of Biology and Environment, Nanjing Agricultural University, 1 Weigang Road, Nanjing, 210095, China
| | - Zhen Li
- Department of Soil Pollution and Control, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Zhengyi Hu
- Sino-Danish College, College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Beidou Xi
- College of Environmental Science and Engineering, Tianjin University, Tianjin, 300035, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
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Gurruchaga-Pereda J, Martínez-Martínez V, Rezabal E, Lopez X, Garino C, Mancin F, Cortajarena AL, Salassa L. Flavin Bioorthogonal Photocatalysis Toward Platinum Substrates. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02863] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Juan Gurruchaga-Pereda
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, Donostia, 20018, Spain
- CIC biomaGUNE, Paseo de Miramón 182, Donostia, 20014, Spain
| | | | - Elixabete Rezabal
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, Donostia, 20018, Spain
- Kimika Fakultatea, Euskal Herriko Unibertsitatea, UPV/EHU, Donostia, 20080, Spain
| | - Xabier Lopez
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, Donostia, 20018, Spain
- Kimika Fakultatea, Euskal Herriko Unibertsitatea, UPV/EHU, Donostia, 20080, Spain
| | - Claudio Garino
- Department of Chemistry, University of Turin, via Pietro Giuria 7, Turin, 10125, Italy
| | - Fabrizio Mancin
- Dipartimento di Scienze Chimiche, Università di Padova, via Marzolo 1, Padova, 35131, Italy
| | - Aitziber L. Cortajarena
- CIC biomaGUNE, Paseo de Miramón 182, Donostia, 20014, Spain
- Ikerbasque, Basque Foundation for Science, Bilbao, 48011, Spain
| | - Luca Salassa
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, Donostia, 20018, Spain
- Ikerbasque, Basque Foundation for Science, Bilbao, 48011, Spain
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144
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He P, Yu Z, Shao L, Zhou Y, Lü F. Fate of antibiotics and antibiotic resistance genes in a full-scale restaurant food waste treatment plant: Implications of the roles beyond heavy metals and mobile genetic elements. J Environ Sci (China) 2019; 85:17-34. [PMID: 31471024 DOI: 10.1016/j.jes.2019.04.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 06/10/2023]
Abstract
Is our food safe and free of the crisis of antibiotics and antibiotic resistance (AR)? And will the derived food waste (FW) impose AR risk to the environment after biological treatment? This study used restaurant FW leachates flowing through a 200 tons-waste/day biological treatment plant as a window to investigate the fate of antibiotics and antibiotic-resistance genes (ARGs) during the acceptance and treatment of FW. Sulfonamides (sulfamethazine, sulfamethoxazole) and quinolones (ciprofloxacin, enrofloxacin, ofloxacin) were detected during FW treatment, while tetracyclines, macrolides and chloramphenicols were not observable. ARGs encoding resistance to sulfonamides, tetracyclines and macrolides emerged in FW leachates. Material flow analysis illustrated that the total amount of antibiotics (except sulfamethazine) and ARGs were constant during FW treatment processes. Both the concentration and total amount of most antibiotics and ARGs fluctuated during treatment, physical processes (screening, centrifugation, solid-liquid and oil-water separation) did not decrease antibiotic or ARGs concentrations or total levels permanently; the affiliated wastewater treatment plant appeared to remove sulfonamides and most ARGs concentrations and total amount. Heavy metals Ni, Co and Cu were important for disseminating antibiotics concentrations and MGEs for distributing ARGs concentrations. Humic substances (fulvic acids, hydrophilic fractions), C-associated and N-associated contents were essential for the distribution of the total amounts of antibiotics and ARGs. Overall, this study implied that human food might not be free of antibiotics and ARGs, and FW was an underestimated AR pool with various determinants. Nonetheless, derived hazards of FW could be mitigated through biological treatment with well-planned daily operations.
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Affiliation(s)
- Pinjing He
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China; Institute of Waste Treatment and Reclamation, Tongji University, Shanghai 200092, China; Centre for the Technology Research and Training on Household Waste in Small Towns & Rural Area, Ministry of Housing and Urban-Rural Development of PR China (MOHURD), China
| | - Zhuofeng Yu
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Liming Shao
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai 200092, China; Centre for the Technology Research and Training on Household Waste in Small Towns & Rural Area, Ministry of Housing and Urban-Rural Development of PR China (MOHURD), China
| | - Yizhou Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Fan Lü
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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145
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Dashti N, Ali N, Khanafer M, Radwan SS. Plant-based oil-sorbents harbor native microbial communities effective in spilled oil-bioremediation under nitrogen starvation and heavy metal-stresses. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 181:78-88. [PMID: 31176250 DOI: 10.1016/j.ecoenv.2019.05.072] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 05/20/2019] [Accepted: 05/25/2019] [Indexed: 06/09/2023]
Abstract
Cultivation on selective media revealed that the oil-sorbents, wheat straw, corncobs and sugarcane bagasse harbor hydrocarbonoclastic, diazotrophic and heavy metal-resistant microorganisms. Nitrogen-free media containing 1.0% crude oil lost between 32.2 and 37.5% of this oil, after 8 months when they have been inoculated with such microorganism-loaded sorbents. The used wheat straw, corncobs and sugarcane bagasse samples, 1.0 g each, absorbed respectively, 1.9, 1.1 and 2.5 g oil samples, and lost 24.3-39.2% of these amounts, after they had been incubated for 8 months. Total genomic DNA's from culture media and sorbents revealed various nitrogenase-coding nifH-genes. Pure hydrocarbonoclastic microbial isolates tolerated certain concentrations of, Hg2+, Cd2+, Pb2+, AsO43- and AsO33-. Some of those isolates even grew excellently with up to 1000 ppm of Pb2+ and 36,000 ppm of AsO43- also in the presence of oil. Tested strains removed the tested heavy metals, Hg2+, Cd2+ and Pb2+ from the media and thus, reduced their toxicity against the hydrocarbon-degraders. It was concluded that plant-based sorbents, not only remove oil physically, but also harbor microbial communities effective in spilled oil-bioremediation under multiple stresses. Although each community consisted of one to three species only, the consortia which reached in numbers millions of CFU ml-1 enrich the oily media with fixed nitrogen, and remove heavy metals which otherwise inhibit the oil-degrading microorganisms.
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Affiliation(s)
- N Dashti
- Microbiology Program, Department of Biological Sciences, Faculty of Science, Kuwait University, P.O. Box 5969, Safat, 13060, Kuwait
| | - N Ali
- Microbiology Program, Department of Biological Sciences, Faculty of Science, Kuwait University, P.O. Box 5969, Safat, 13060, Kuwait
| | - M Khanafer
- Microbiology Program, Department of Biological Sciences, Faculty of Science, Kuwait University, P.O. Box 5969, Safat, 13060, Kuwait
| | - S S Radwan
- Microbiology Program, Department of Biological Sciences, Faculty of Science, Kuwait University, P.O. Box 5969, Safat, 13060, Kuwait.
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146
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Biosensors in Monitoring Water Quality and Safety: An Example of a Miniaturizable Whole-Cell Based Sensor for Hg2+ Optical Detection in Water. WATER 2019. [DOI: 10.3390/w11101986] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Inorganic mercury (Hg2+) pollution of water reserves, especially drinking water, is an important issue in the environmental and public health field. Mercury is reported to be one of the most dangerous elements in nature since its accumulation and ingestion can lead to a series of permanent human diseases, affecting the kidneys and central nervous system. All the conventional approaches for assaying Hg2+ have some limitations in terms of bulky instruments and the cost and time required for the analysis. Here, we describe a miniaturizable and high-throughput bioluminescence sensor for Hg2+ detection in water, which combines the specificity of a living bacterial Hg2+ reporter cell, used as sensing element, with the performance of a silicon photomultiplier, used as optical detector. The proposed system paves the basis for portable analysis and low reactants consumption. The aim of the work is to propose a sensing strategy for total inorganic mercury evaluation in water. The proposed system can lay the basis for further studies and validations in order to develop rapid and portable technology that can be used in situ providing remote monitoring.
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147
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Jiang D, Xue X, Zhu M, Zhang G, Wang Y, Feng C, Wang Z, Zhao H. Novel Rhodamine-Derivated Dual-Responsive Colorimetric Fluorescent Chemoprobe for the Hypersensitive Detection of Ga3+ and Hg2+ and Biological Imaging. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b03865] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Daoyong Jiang
- School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Xingying Xue
- School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Mei Zhu
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Guoning Zhang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Yucheng Wang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Chao Feng
- School of Materials and Chemical Engineering, Bengbu University, Bengbu 233030, PR China
| | - Zhifei Wang
- School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Hong Zhao
- School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
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148
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Lemos LN, Medeiros JD, Dini-Andreote F, Fernandes GR, Varani AM, Oliveira G, Pylro VS. Genomic signatures and co-occurrence patterns of the ultra-small Saccharimonadia (phylum CPR/Patescibacteria) suggest a symbiotic lifestyle. Mol Ecol 2019; 28:4259-4271. [PMID: 31446647 DOI: 10.1111/mec.15208] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 07/29/2019] [Indexed: 01/31/2023]
Abstract
The size of bacterial genomes is often associated with organismal metabolic capabilities determining ecological breadth and lifestyle. The recently proposed Candidate Phyla Radiation (CPR)/Patescibacteria encompasses mostly unculturable bacterial taxa with relatively small genome sizes with potential for co-metabolism interdependencies. As yet, little is known about the ecology and evolution of CPR, particularly with respect to how they might interact with other taxa. Here, we reconstructed two novel genomes (namely, Candidatus Saccharibacter sossegus and Candidatus Chaer renensis) of taxa belonging to the class Saccharimonadia within the CPR/Patescibacteria using metagenomes obtained from acid mine drainage (AMD). By testing the hypothesis of genome streamlining or symbiotic lifestyle, our results revealed clear signatures of gene losses in these genomes, such as those associated with de novo biosynthesis of essential amino acids, nucleotides, fatty acids and cofactors. In addition, co-occurrence analysis provided evidence supporting potential symbioses of these organisms with Hydrotalea sp. in the AMD system. Together, our findings provide a better understanding of the ecology and evolution of CPR/Patescibacteria and highlight the importance of genome reconstruction for studying metabolic interdependencies between unculturable Saccharimonadia representatives.
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Affiliation(s)
- Leandro N Lemos
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture CENA, University of São Paulo USP, Piracicaba, Brazil
| | - Julliane D Medeiros
- Department of Parasitology, Microbiology and Immunology, Federal University of Juiz de Fora (UFJF), Juiz de Fora, Brazil
| | - Francisco Dini-Andreote
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Gabriel R Fernandes
- Biosystems Informatics and Genomics Group, René Rachou Institute, FIOCRUZ-Minas, Belo Horizonte, Brazil
| | - Alessandro M Varani
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista (Unesp), Jaboticabal, Brazil
| | | | - Victor S Pylro
- Microbial Ecology and Bioinformatics Laboratory, Department of Biology, Federal University of Lavras (UFLA), Lavras, Brazil
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149
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Genomic Sequence Analysis of the Multidrug-Resistance Region of Avian Salmonella enterica serovar Indiana Strain MHYL. Microorganisms 2019; 7:microorganisms7080248. [PMID: 31404981 PMCID: PMC6723982 DOI: 10.3390/microorganisms7080248] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/06/2019] [Accepted: 08/07/2019] [Indexed: 12/19/2022] Open
Abstract
A series of human and animal diseases that are caused by Salmonella infections pose a serious threat to human health and huge economic losses to the livestock industry. We found antibiotic resistance (AR) genes in the genome of 133 strains of S. Indiana from a poultry production site in Shandong Province, China. Salmonella enterica subsp. enterica serovar Indiana strain MHYL had multidrug-resistance (MDR) genes on its genome. Southern blot analysis was used to locate genes on the genomic DNA. High-throughput sequencing technology was used to determine the gene sequence of the MHYL genome. Areas containing MDR genes were mapped based on the results of gene annotation. The AR genes blaTEM, strA, tetA, and aac(6′)-Ib-cr were found on the MHYL genome. The resistance genes were located in two separate MDR regions, RR1 and RR2, containing type I integrons, and Tn7 transposons and multiple IS26 complex transposons with transposable functions. Portions of the MDR regions were determined to be highly homologous to the structure of plasmid pAKU_1 in S. enterica serovar Paratyphi A (accession number: AM412236), SGI11 in S. enterica serovar Typhimurium (accession number: KM023773), and plasmid pS414 in S. Indiana (accession No.: KC237285).
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150
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Kruse T, Ratnadevi CM, Erikstad HA, Birkeland NK. Complete genome sequence analysis of the thermoacidophilic verrucomicrobial methanotroph "Candidatus Methylacidiphilum kamchatkense" strain Kam1 and comparison with its closest relatives. BMC Genomics 2019; 20:642. [PMID: 31399023 PMCID: PMC6688271 DOI: 10.1186/s12864-019-5995-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/26/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The candidate genus "Methylacidiphilum" comprises thermoacidophilic aerobic methane oxidizers belonging to the Verrucomicrobia phylum. These are the first described non-proteobacterial aerobic methane oxidizers. The genes pmoCAB, encoding the particulate methane monooxygenase do not originate from horizontal gene transfer from proteobacteria. Instead, the "Ca. Methylacidiphilum" and the sister genus "Ca. Methylacidimicrobium" represent a novel and hitherto understudied evolutionary lineage of aerobic methane oxidizers. Obtaining and comparing the full genome sequences is an important step towards understanding the evolution and physiology of this novel group of organisms. RESULTS Here we present the closed genome of "Ca. Methylacidiphilum kamchatkense" strain Kam1 and a comparison with the genomes of its two closest relatives "Ca. Methylacidiphilum fumariolicum" strain SolV and "Ca. Methylacidiphilum infernorum" strain V4. The genome consists of a single 2,2 Mbp chromosome with 2119 predicted protein coding sequences. Genome analysis showed that the majority of the genes connected with metabolic traits described for one member of "Ca. Methylacidiphilum" is conserved between all three genomes. All three strains encode class I CRISPR-cas systems. The average nucleotide identity between "Ca. M. kamchatkense" strain Kam1 and strains SolV and V4 is ≤95% showing that they should be regarded as separate species. Whole genome comparison revealed a high degree of synteny between the genomes of strains Kam1 and SolV. In contrast, comparison of the genomes of strains Kam1 and V4 revealed a number of rearrangements. There are large differences in the numbers of transposable elements found in the genomes of the three strains with 12, 37 and 80 transposable elements in the genomes of strains Kam1, V4 and SolV respectively. Genomic rearrangements and the activity of transposable elements explain much of the genomic differences between strains. For example, a type 1h uptake hydrogenase is conserved between strains Kam1 and SolV but seems to have been lost from strain V4 due to genomic rearrangements. CONCLUSIONS Comparing three closed genomes of "Ca. Methylacidiphilum" spp. has given new insights into the evolution of these organisms and revealed large differences in numbers of transposable elements between strains, the activity of these explains much of the genomic differences between strains.
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Affiliation(s)
- Thomas Kruse
- Department of Biological Sciences, University of Bergen, P.O. Box 7803, 5020, Bergen, Norway.
| | | | - Helge-André Erikstad
- Department of Biological Sciences, University of Bergen, P.O. Box 7803, 5020, Bergen, Norway
| | - Nils-Kåre Birkeland
- Department of Biological Sciences, University of Bergen, P.O. Box 7803, 5020, Bergen, Norway.
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