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Hui CY, Ma BC, Hu SY, Wu C. Tailored bacteria tackling with environmental mercury: Inspired by natural mercuric detoxification operons. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 341:123016. [PMID: 38008253 DOI: 10.1016/j.envpol.2023.123016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/30/2023] [Accepted: 11/19/2023] [Indexed: 11/28/2023]
Abstract
Mercury (Hg) and its inorganic and organic compounds significantly threaten the ecosystem and human health. However, the natural and anthropogenic Hg environmental inputs exceed 5000 metric tons annually. Hg is usually discharged in elemental or ionic forms, accumulating in surface water and sediments where Hg-methylating microbes-mediated biotransformation occurs. Microbial genetic factors such as the mer operon play a significant role in the complex Hg biogeochemical cycle. Previous reviews summarize the fate of environmental Hg, its biogeochemistry, and the mechanism of bacterial Hg resistance. This review mainly focuses on the mer operon and its components in detecting, absorbing, bioaccumulating, and detoxifying environmental Hg. Four components of the mer operon, including the MerR regulator, divergent mer promoter, and detoxification factors MerA and MerB, are rare bio-parts for assembling synthetic bacteria, which tackle pollutant Hg. Bacteria are designed to integrate synthetic biology, protein engineering, and metabolic engineering. In summary, this review highlights that designed bacteria based on the mer operon can potentially sense and bioremediate pollutant Hg in a green and low-cost manner.
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Affiliation(s)
- Chang-Ye Hui
- Shenzhen Prevention and Treatment Center for Occupational Diseases, 2019 Buxin Road, Shenzhen, 518020, China.
| | - Bing-Chan Ma
- Shenzhen Prevention and Treatment Center for Occupational Diseases, 2019 Buxin Road, Shenzhen, 518020, China; School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, China
| | - Shun-Yu Hu
- Shenzhen Prevention and Treatment Center for Occupational Diseases, 2019 Buxin Road, Shenzhen, 518020, China; Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, 510515, China
| | - Can Wu
- Shenzhen Prevention and Treatment Center for Occupational Diseases, 2019 Buxin Road, Shenzhen, 518020, China; Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, 510515, China
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Gouveia AG, Salgueiro BA, Ranmar DO, Antunes WDT, Kirchweger P, Golani O, Wolf SG, Elbaum M, Matias PM, Romão CV. Unraveling the multifaceted resilience of arsenic resistant bacterium Deinococcus indicus. Front Microbiol 2023; 14:1240798. [PMID: 37692390 PMCID: PMC10483234 DOI: 10.3389/fmicb.2023.1240798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 08/09/2023] [Indexed: 09/12/2023] Open
Abstract
Arsenic (As) is a toxic heavy metal widely found in the environment that severely undermines the integrity of water resources. Bioremediation of toxic compounds is an appellative sustainable technology with a balanced cost-effective setup. To pave the way for the potential use of Deinococcus indicus, an arsenic resistant bacterium, as a platform for arsenic bioremediation, an extensive characterization of its resistance to cellular insults is paramount. A comparative analysis of D. indicus cells grown in two rich nutrient media conditions (M53 and TGY) revealed distinct resistance patterns when cells are subjected to stress via UV-C and methyl viologen (MV). Cells grown in M53 demonstrated higher resistance to both UV-C and MV. Moreover, cells grow to higher density upon exposure to 25 mM As(V) in M53 in comparison with TGY. This analysis is pivotal for the culture of microbial species in batch culture bioreactors for bioremediation purposes. We also demonstrate for the first time the presence of polyphosphate granules in D. indicus which are also found in a few Deinococcus species. To extend our analysis, we also characterized DiArsC2 (arsenate reductase) involved in arsenic detoxification and structurally determined different states, revealing the structural evidence for a catalytic cysteine triple redox system. These results contribute for our understanding into the D. indicus resistance mechanism against stress conditions.
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Affiliation(s)
- André G. Gouveia
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
| | - Bruno A. Salgueiro
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
| | - Dean O. Ranmar
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Wilson D. T. Antunes
- Instituto Universitário Militar, Centro de Investigação da Academia Militar (CINAMIL), Unidade Militar Laboratorial de Defesa Biológica e Química (UMLDBQ), Lisbon, Portugal
| | - Peter Kirchweger
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Ofra Golani
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Sharon G. Wolf
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Michael Elbaum
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Pedro M. Matias
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
- Instituto de Biologia Experimental e Tecnológica (iBET), Oeiras, Portugal
| | - Célia V. Romão
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
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Meyer L, Guyot S, Chalot M, Capelli N. The potential of microorganisms as biomonitoring and bioremediation tools for mercury-contaminated soils. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 262:115185. [PMID: 37385017 DOI: 10.1016/j.ecoenv.2023.115185] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/20/2023] [Accepted: 06/24/2023] [Indexed: 07/01/2023]
Abstract
Mercury (Hg) pollution is a global issue due to the high toxicity and wide dispersion of Hg around the world. Whether due to anthropogenic activities or natural processes, Hg emissions are steadily increasing, with very high levels in some regions, directly threatening human and ecosystem health. However, bacteria and fungi have evolved and adapted in response to Hg-induced stress and have developed tolerance mechanisms, notably based on the mer operon system that is involved in Hg uptake and biovolatilization via Hg reduction reactions. Other processes, such as bioaccumulation or extracellular sequestration, are involved in Hg resistance, and the study of contaminated soils has allowed the isolation of a number of microorganisms capable of these mechanisms, with strong potential for the implementation of bioremediation approaches. In addition to playing an important role in determining the fate of Hg in the biogeochemical cycle, these microorganisms can indeed be applied to reduce Hg concentrations or at least stabilize Hg for the remediation of polluted soils. Moreover, thanks to the development of biotechnological tools, bioremediation based on Hg-tolerant microorganisms can be optimized. Finally, these microorganisms are relevant candidates for biomonitoring, for example, through the engineering of biosensors, because the detection of Hg is a major issue in preserving the health of living beings.
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Affiliation(s)
- Lorraine Meyer
- Chrono-environnement UMR 6249, Université de Franche-Comté CNRS, F-25000 Besançon, France
| | - Stéphane Guyot
- Université de Bourgogne, Institut Agro, PAM UMR A 02.102, F-21000 Dijon, France
| | - Michel Chalot
- Chrono-environnement UMR 6249, Université de Franche-Comté CNRS, F-25000 Besançon, France; Université de Lorraine, F-54000 Nancy, France
| | - Nicolas Capelli
- Chrono-environnement UMR 6249, Université de Franche-Comté CNRS, F-25000 Besançon, France.
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Chandwadkar P, Acharya C. Inorganic polyphosphate accumulation protects a marine, filamentous cyanobacterium, Anabaena torulosa against uranium toxicity. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2023; 263:107185. [PMID: 37094505 DOI: 10.1016/j.jenvrad.2023.107185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/28/2023] [Accepted: 04/14/2023] [Indexed: 05/03/2023]
Abstract
The intricate dynamics of inorganic polyphosphate (polyP) in response to phosphorus (P) limitation and metal exposure typical of contaminated aquatic environments is poorly understood. Cyanobacteria are important primary producers in aquatic environments that are exposed to P stringency as well as metal contamination. There is a growing concern regarding migration of uranium, generated as a result of anthropogenic activities, into the aquatic environments owing to high mobility and solubility of stable aqueous complexes of uranyl ions. The polyP metabolism in cyanobacteria in context of uranium (U) exposure under P limitation has hardly been explored. In this study, we analyzed the polyP dynamics in a marine, filamentous cyanobacterium Anabaena torulosa under combination of variable phosphate concentrations (overplus and deficient) and uranyl exposure conditions typical of marine environments. Polyphosphate accumulation (polyP+) or deficient (polyP-) conditions were physiologically synthesized in the A. torulosa cultures and were ascertained by (a) toulidine blue staining followed by their visualization using bright field microscopy and (b) scanning electron microscopy in combination with energy dispersive X-ray spectroscopy (SEM/EDX). On exposure to 100 μM of uranyl carbonate at pH 7.8, it was observed that the growth of polyP+ cells under phosphate limitation was hardly affected and these cells exhibited larger amounts of uranium binding as compared to polyP- cells of A. torulosa. In contrast, the polyP- cells displayed extensive lysis when exposed to similar U exposure. Our findings suggest that polyP accumulation played an important role in conferring uranium tolerance in the marine cyanobacterium, A. torulosa. The polyP-mediated uranium tolerance and binding could serve as a suitable strategy for remediation of uranium contamination in aquatic environments.
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Affiliation(s)
- Pallavi Chandwadkar
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India
| | - Celin Acharya
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India; Homi Bhabha National Institute, Anushakti Nagar, Mumbai, India.
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Priyadarshanee M, Chatterjee S, Rath S, Dash HR, Das S. Cellular and genetic mechanism of bacterial mercury resistance and their role in biogeochemistry and bioremediation. JOURNAL OF HAZARDOUS MATERIALS 2022; 423:126985. [PMID: 34464861 DOI: 10.1016/j.jhazmat.2021.126985] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 08/17/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
Mercury (Hg) is a highly toxic element that occurs at low concentrations in nature. However, various anthropogenic and natural sources contribute around 5000 to 8000 metric tons of Hg per year, rapidly deteriorating the environmental conditions. Mercury-resistant bacteria that possess the mer operon system have the potential for Hg bioremediation through volatilization from the contaminated milieus. Thus, bacterial mer operon plays a crucial role in Hg biogeochemistry and bioremediation by converting both reactive inorganic and organic forms of Hg to relatively inert, volatile, and monoatomic forms. Both the broad-spectrum and narrow-spectrum bacteria harbor many genes of mer operon with their unique definitive functions. The presence of mer genes or proteins can regulate the fate of Hg in the biogeochemical cycle in the environment. The efficiency of Hg transformation depends upon the nature and diversity of mer genes present in mercury-resistant bacteria. Additionally, the bacterial cellular mechanism of Hg resistance involves reduced Hg uptake, extracellular sequestration, and bioaccumulation. The presence of unique physiological properties in a specific group of mercury-resistant bacteria enhances their bioremediation capabilities. Many advanced biotechnological tools also can improve the bioremediation efficiency of mercury-resistant bacteria to achieve Hg bioremediation.
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Affiliation(s)
- Monika Priyadarshanee
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology Rourkela, Rourkela 769 008, Odisha, India
| | - Shreosi Chatterjee
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology Rourkela, Rourkela 769 008, Odisha, India
| | - Sonalin Rath
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology Rourkela, Rourkela 769 008, Odisha, India
| | - Hirak R Dash
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology Rourkela, Rourkela 769 008, Odisha, India
| | - Surajit Das
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology Rourkela, Rourkela 769 008, Odisha, India.
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Newsome L, Falagán C. The Microbiology of Metal Mine Waste: Bioremediation Applications and Implications for Planetary Health. GEOHEALTH 2021; 5:e2020GH000380. [PMID: 34632243 PMCID: PMC8490943 DOI: 10.1029/2020gh000380] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 08/17/2021] [Accepted: 08/20/2021] [Indexed: 05/13/2023]
Abstract
Mine wastes pollute the environment with metals and metalloids in toxic concentrations, causing problems for humans and wildlife. Microorganisms colonize and inhabit mine wastes, and can influence the environmental mobility of metals through metabolic activity, biogeochemical cycling and detoxification mechanisms. In this article we review the microbiology of the metals and metalloids most commonly associated with mine wastes: arsenic, cadmium, chromium, copper, lead, mercury, nickel and zinc. We discuss the molecular mechanisms by which bacteria, archaea, and fungi interact with contaminant metals and the consequences for metal fate in the environment, focusing on long-term field studies of metal-impacted mine wastes where possible. Metal contamination can decrease the efficiency of soil functioning and essential element cycling due to the need for microbes to expend energy to maintain and repair cells. However, microbial communities are able to tolerate and adapt to metal contamination, particularly when the contaminant metals are essential elements that are subject to homeostasis or have a close biochemical analog. Stimulating the development of microbially reducing conditions, for example in constructed wetlands, is beneficial for remediating many metals associated with mine wastes. It has been shown to be effective at low pH, circumneutral and high pH conditions in the laboratory and at pilot field-scale. Further demonstration of this technology at full field-scale is required, as is more research to optimize bioremediation and to investigate combined remediation strategies. Microbial activity has the potential to mitigate the impacts of metal mine wastes, and therefore lessen the impact of this pollution on planetary health.
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Affiliation(s)
- Laura Newsome
- Camborne School of Mines and Environment and Sustainability InstituteUniversity of ExeterPenrynUK
| | - Carmen Falagán
- Camborne School of Mines and Environment and Sustainability InstituteUniversity of ExeterPenrynUK
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Rani L, Srivastav AL, Kaushal J. Bioremediation: An effective approach of mercury removal from the aqueous solutions. CHEMOSPHERE 2021; 280:130654. [PMID: 34162069 DOI: 10.1016/j.chemosphere.2021.130654] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 04/03/2021] [Accepted: 04/21/2021] [Indexed: 06/13/2023]
Abstract
Mercury (Hg(II)) is the 16th rarest element present in the earth's crust. Due to rapid industrialization and urban expansions, the mercury concentration has been elevated in the environment. Hg(II) contamination in the aqueous environment has become a great challenge for human beings. The main source of Hg(II) in the aqueous phase is untreated effluent industries (such as the paper industry). Hg(II) is non-biodegradable in nature and even its trace amount in an aqueous environment can pose chronic threats among the humans (damage to the central nervous system, respiratory system, and cardiovascular system, mutation of DNA), animals, and aquatic creatures. Therefore, the removal of mercury from aqueous solutions is an urgent need of the modern era. The conventional techniques such as ion exchange, precipitation, membrane filtrations are costly and also generate byproducts in the environment. Bioremediation is a sustainable, environmentally sound, and cost-effective technique to remove Hg(II) from the aqueous solutions. In this process, naturally occurring microorganisms are utilized to remove the Hg(II) from the aqueous solutions. Lentinus edodes, U. lactuca, and Typha domingensis are found to have great potential to remove mercury from water ranged from ~100 mg g-1 to 337 mg g-1.
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Affiliation(s)
- Lata Rani
- Centre for Water Sciences, Chitkara University Institute of Engineering & Technology, Chitkara University, Punjab, 140 417, India; School of Basic Sciences, Chitkara University, Himachal Pradesh, 174 103, India
| | - Arun Lal Srivastav
- Chitkara University School of Engineering and Technology, Chitkara University, Himachal Pradesh, 174 103, India.
| | - Jyotsna Kaushal
- Centre for Water Sciences, Chitkara University Institute of Engineering & Technology, Chitkara University, Punjab, 140 417, India
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Singh S, Kumar V, Gupta P, Ray M, Singh A. An implication of biotransformation in detoxification of mercury contamination by Morganella sp. strain IITISM23. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:35661-35677. [PMID: 33677667 DOI: 10.1007/s11356-021-13176-2] [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] [Received: 12/28/2020] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
The contamination of soil by heavy metals such as Hg is growing immensely nowadays. The drawbacks of physicochemical methods in the decontamination of polluted soils resulted in the search for an eco-friendly and cost-effective means in this regard. In this study, a potential Hg-resistant bacterial (IITISM23) strain was investigated for their removal potential of Hg, isolated from Hg-contaminated soil. IITISM23 strain was identified as Morganella sp. (MT062474.1) as it showed 99% similarity to genus Morganella of Gammaproteobacteria based on 16S rRNA gene sequencing. The toxicity experiment confirmed that the strain showed high resistance toward Hg. In low nutrient medium, EC50 (effective concentration) values were 6.8 ppm and minimum effective concentration (MIC) was 7.3 ppm, and in a nutrient-rich medium, EC50 value was 32.29 ppm and MIC value was 34.92 ppm, respectively. In in vitro conditions, IITISM23 showed the removal efficiency (81%) of Hg (II) by the volatilization method in Luria-Bertani (LB) broth. The changes in surface morphology of bacteria upon the supplementation of Hg (II) in broth media were determined by SEM-EDX studies, while the changes in functional groups were studied by FT-IR spectroscopy. The mercury reductase activity was determined by a crude extract of the bacterial strain. The optimal pH and temperature for maximum enzyme activity were 8 and 30oC, with Km of 3.5 μmol/l and Vmax of 0.88 μmol/min, respectively. Also, strain IITISM23 showed resistance toward various antibiotics and other heavy metals like cadmium, lead, arsenic, and zinc. Hence, the application of microbes can be an effective measure in the decontamination of Hg from polluted soils.
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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.
| | - Pratishtha Gupta
- Laboratory of Applied Microbiology, Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand, 826 004, India
| | - Madhurya Ray
- Laboratory of Applied Microbiology, Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand, 826 004, India
| | - Ankur Singh
- 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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Sharma P. Efficiency of bacteria and bacterial assisted phytoremediation of heavy metals: An update. BIORESOURCE TECHNOLOGY 2021; 328:124835. [PMID: 33618184 DOI: 10.1016/j.biortech.2021.124835] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/05/2021] [Accepted: 02/07/2021] [Indexed: 05/12/2023]
Abstract
The aim of this review to address the plant-associated bacteria to enhance the phytoremediation efficiency of the heavy metals from polluted sites and it is also highlighted advances for the application in wastewater treatment. Plant-associated bacteria have potential to encourage the plant growth and resistance under stress conditions. Such bacteria could enhance plant growth by controlling growth hormone, nutrition security, producing siderophore, secondary metabolites, and improving the antioxidant enzymes system. This review also explores the concepts and applications of bacteria assisted phytoremediation, addressing aspects that affect phytoremediation and pathways for restoration. Significant review issues relating to production and application of bacteria for improvement of bioremediation were established and presented for possible future research. Bacteria assisted phytoremediation is cost-effective strategy and metal sequestration mechanism that hold high metal biosorption capacities. This also takes into consideration the current state of technology implementations and proposals for prospective clean-up studies.
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Affiliation(s)
- Pooja Sharma
- Department of Environmental Microbiology, School for Environmental Sciences, Babasaheb Bhimrao Ambedkar Central University, Lucknow 226 025, Uttar Pradesh, India
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Pinto OHB, Costa FS, Rodrigues GR, da Costa RA, da Rocha Fernandes G, Júnior ORP, Barreto CC. Soil Acidobacteria Strain AB23 Resistance to Oxidative Stress Through Production of Carotenoids. MICROBIAL ECOLOGY 2021; 81:169-179. [PMID: 32617619 DOI: 10.1007/s00248-020-01548-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 06/16/2020] [Indexed: 06/11/2023]
Abstract
Metagenomic studies revealed the prevalence of Acidobacteria in soils, but the physiological and ecological reasons for their success are not well understood. Many Acidobacteria exhibit carotenoid-related pigments, which may be involved in their tolerance of environmental stress. The aim of this work was to investigate the role of the orange pigments produced by Acidobacteria strain AB23 isolated from a savannah-like soil and to identify putative carotenoid genes in Acidobacteria genomes. Phylogenetic analysis revealed that strain AB23 belongs to the Occallatibacter genus from the class Acidobacteriia (subdivision 1). Strain AB23 produced carotenoids in the presence of light and vitamins; however, the growth rate and biomass decreased when cells were exposed to light. The presence of carotenoids resulted in tolerance to hydrogen peroxide. Comparative genomics revealed that all members of Acidobacteriia with available genomes possess the complete gene cluster for phytoene production. Some Acidobacteriia members have an additional gene cluster that may be involved in the production of colored carotenoids. Both colored and colorless carotenoids are involved in tolerance to oxidative stress. These results show that the presence of carotenoid genes is widespread among Acidobacteriia. Light and atmospheric oxygen stimulate carotenoid synthesis, but there are other natural sources of oxidative stress in soils. Tolerance to environmental oxidative stress provided by carotenoids may offer a competitive advantage for Acidobacteria in soils.
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Affiliation(s)
- Otávio Henrique Bezerra Pinto
- Graduate Program in Genomic Sciences and Biotechnology, Catholic University of Brasília, SGAN 916 Módulo B Avenida W5 - Asa Norte, Brasília, 70790-160, Brazil
- Laboratory of Enzymology, Institute of Biological Sciences, Department of Cell Biology, University of Brasília, Brasília, 70910-900, Brazil
| | - Flávio Silva Costa
- Graduate Program in Genomic Sciences and Biotechnology, Catholic University of Brasília, SGAN 916 Módulo B Avenida W5 - Asa Norte, Brasília, 70790-160, Brazil
- Institute of Microbiology, Friedrich Schiller University Jena, Neugasse 25, 07743, Jena, Germany
| | - Gisele Regina Rodrigues
- Graduate Program in Genomic Sciences and Biotechnology, Catholic University of Brasília, SGAN 916 Módulo B Avenida W5 - Asa Norte, Brasília, 70790-160, Brazil
| | - Rosiane Andrade da Costa
- Graduate Program in Genomic Sciences and Biotechnology, Catholic University of Brasília, SGAN 916 Módulo B Avenida W5 - Asa Norte, Brasília, 70790-160, Brazil
| | - Gabriel da Rocha Fernandes
- Research Center René Rachou, Oswaldo Cruz Foundation (Fiocruz), Avenida Augusto de Lima 1715, Barro Preto, Belo Horizonte, 30190-002, Brazil
| | - Osmindo Rodrigues Pires Júnior
- Department of Physiological Sciences, Institute of Biological Sciences, Universidade de Brasília, Brasília, DF, 70910-900, Brazil
| | - Cristine Chaves Barreto
- Graduate Program in Genomic Sciences and Biotechnology, Catholic University of Brasília, SGAN 916 Módulo B Avenida W5 - Asa Norte, Brasília, 70790-160, Brazil.
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De Oliveira VH, Ullah I, Dunwell JM, Tibbett M. Bioremediation potential of Cd by transgenic yeast expressing a metallothionein gene from Populus trichocarpa. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 202:110917. [PMID: 32800252 DOI: 10.1016/j.ecoenv.2020.110917] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/09/2020] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
Cadmium (Cd) is an extremely toxic environmental pollutant with high mobility in soils, which can contaminate groundwater, increasing its risk of entering the food chain. Yeast biosorption can be a low-cost and effective method for removing Cd from contaminated aqueous solutions. We transformed wild-type Saccharomyces cerevisiae (WT) with two versions of a Populus trichocarpa gene (PtMT2b) coding for a metallothionein: one with the original sequence (PtMT2b 'C') and the other with a mutated sequence, with an amino acid substitution (C3Y, named here: PtMT2b 'Y'). WT and both transformed yeasts were grown under Cd stress, in agar (0; 10; 20; 50 μM Cd) and liquid medium (0; 10; 20 μM Cd). Yeast growth was assessed visually and by spectrometry OD600. Cd removal from contaminated media and intracellular accumulation were also quantified. PtMT2b 'Y' was also inserted into mutant strains: fet3fet4, zrt1zrt2 and smf1, and grown under Fe-, Zn- and Mn-deficient media, respectively. Yeast strains had similar growth under 0 μM, but differed under 20 μM Cd, the order of tolerance was: WT < PtMT2b 'C' < PtMT2b 'Y', the latter presenting 37% higher growth than the strain with PtMT2b 'C'. It also extracted ~80% of the Cd in solution, and had higher intracellular Cd than WT. Mutant yeasts carrying PtMT2b 'Y' had slightly higher growth in Mn- and Fe-deficient media than their non-transgenic counterparts, suggesting the transgenic protein may chelate these metals. S. cerevisiae carrying the altered poplar gene offers potential for bioremediation of Cd from wastewaters or other contaminated liquids.
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Affiliation(s)
- Vinicius Henrique De Oliveira
- Department of Sustainable Land Management & Soil Research Centre, School of Agricultura, Policy and Development, University of Reading, RG6 6AR, UK
| | - Ihsan Ullah
- School of Agriculture, Policy and Development, University of Reading, RG6 6AR, UK
| | - Jim M Dunwell
- School of Agriculture, Policy and Development, University of Reading, RG6 6AR, UK
| | - Mark Tibbett
- Department of Sustainable Land Management & Soil Research Centre, School of Agricultura, Policy and Development, University of Reading, RG6 6AR, UK.
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Rahman Z, Singh VP. Bioremediation of toxic heavy metals (THMs) contaminated sites: concepts, applications and challenges. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:27563-27581. [PMID: 32418096 DOI: 10.1007/s11356-020-08903-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/15/2020] [Indexed: 06/11/2023]
Abstract
Heavy metal contamination is a global issue, where the prevalent contaminants are arsenic (As), cadmium (Cd), chromium (Cr)(VI), mercury (Hg), and lead (Pb). More often, they are collectively known as "most problematic heavy metals" and "toxic heavy metals" (THMs). Their treatment through a variety of biological processes is one of the prime interests in remediation studies, where heavy metal-microbe interaction approaches receive high interest for their cost effective and ecofriendly solutions. In this review, we provide an up to date information on different microbial processes (bioremediation) for the removal of THMs. For the same, emphasis is put on oxidation-reduction, biomineralization, bioprecipitation, bioleaching, biosurfactant technology, biovolatilization, biosorption, bioaccumulation, and microbe-assisted phytoremediation with their selective advantages and disadvantages. Further, the literature briefly discusses about the various setups of cleaning processes of THMs in environment under ex situ and in situ applications. Lately, the study sheds light on the manipulation of microorganisms through genetic engineering and nanotechnology for their advanced treatment approaches.
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Affiliation(s)
- Zeeshanur Rahman
- Department of Botany, Zakir Husain Delhi College, University of Delhi, Delhi, India.
- Department of Botany, University of Delhi, Delhi, India.
| | - Ved Pal Singh
- Department of Botany, University of Delhi, Delhi, India
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Abstract
How do organisms deal with free iron? On the one hand, iron is an essential metal that plays crucial structural and functional roles in many organisms. On the other hand, free iron is extremely toxic, particularly under aerobic conditions, where iron rapidly undergoes the Fenton reaction and produces highly reactive hydroxyl radicals. Our study now demonstrates that we have discovered one of the first physiologically relevant nonproteinaceous iron chelators and Fenton inhibitors. We found that polyphosphate, a highly conserved and ubiquitous inorganic polyanion, chelates iron and, through its multivalency, prevents the interaction of iron with peroxide and therefore the formation of hydroxyl radicals. We show that polyP provides a crucial iron reservoir for metalloproteins under nonstress conditions and effectively chelates free iron during iron stress. Importantly, polyP is present in all cells and organisms and hence is likely to take on this crucial function in both prokaryotic and eukaryotic cells. Maintaining cellular iron homeostasis is critical for organismal survival. Whereas iron depletion negatively affects the many metabolic pathways that depend on the activity of iron-containing enzymes, any excess of iron can cause the rapid formation of highly toxic reactive oxygen species (ROS) through Fenton chemistry. Although several cellular iron chelators have been identified, little is known about if and how organisms can prevent the Fenton reaction. By studying the effects of cisplatin, a commonly used anticancer drug and effective antimicrobial, we discovered that cisplatin elicits severe iron stress and oxidative DNA damage in bacteria. We found that both of these effects are successfully prevented by polyphosphate (polyP), an abundant polymer consisting solely of covalently linked inorganic phosphates. Subsequent in vitro and in vivo studies revealed that polyP provides a crucial iron reservoir under nonstress conditions and effectively complexes free iron and blocks ROS formation during iron stress. These results demonstrate that polyP, a universally conserved biomolecule, plays a hitherto unrecognized role as an iron chelator and an inhibitor of the Fenton reaction.
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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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15
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Balzano S, Sardo A, Blasio M, Chahine TB, Dell’Anno F, Sansone C, Brunet C. Microalgal Metallothioneins and Phytochelatins and Their Potential Use in Bioremediation. Front Microbiol 2020; 11:517. [PMID: 32431671 PMCID: PMC7216689 DOI: 10.3389/fmicb.2020.00517] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 03/10/2020] [Indexed: 01/02/2023] Open
Abstract
The persistence of heavy metals (HMs) in the environment causes adverse effects to all living organisms; HMs accumulate along the food chain affecting different levels of biological organizations, from cells to tissues. HMs enter cells through transporter proteins and can bind to enzymes and nucleic acids interfering with their functioning. Strategies used by microalgae to minimize HM toxicity include the biosynthesis of metal-binding peptides that chelate metal cations inhibiting their activity. Metal-binding peptides include genetically encoded metallothioneins (MTs) and enzymatically produced phytochelatins (PCs). A number of techniques, including genetic engineering, focus on increasing the biosynthesis of MTs and PCs in microalgae. The present review reports the current knowledge on microalgal MTs and PCs and describes the state of art of their use for HM bioremediation and other putative biotechnological applications, also emphasizing on techniques aimed at increasing the cellular concentrations of MTs and PCs. In spite of the broad metabolic and chemical diversity of microalgae that are currently receiving increasing attention by biotechnological research, knowledge on MTs and PCs from these organisms is still limited to date.
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Affiliation(s)
- Sergio Balzano
- Stazione Zoologica Anton Dohrn Napoli (SZN), Naples, Italy
- NIOZ Royal Netherlands Institute for Sea Research, Den Burg, Netherlands
| | - Angela Sardo
- Stazione Zoologica Anton Dohrn Napoli (SZN), Naples, Italy
| | - Martina Blasio
- Stazione Zoologica Anton Dohrn Napoli (SZN), Naples, Italy
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Shahpiri A, Rahimi AM. Expression of Rice Metallothionein Isoforms in Escherichia coli Enhances the Accumulation of Trivalent and Hexavalent Chromium. Protein Pept Lett 2019; 26:768-775. [PMID: 31618171 DOI: 10.2174/0929866526666190503100613] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 04/07/2019] [Accepted: 04/19/2019] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Metallothioneins (MTs) are members of a family of low molecular weight and cysteine-rich proteins that are involved in heavy metal homeostasis and detoxification in living organisms. Plants have multiple MT types that are generally divided into four subgroups according to the arrangement of Cys residues. METHODS In the present study the E. coli cells which heterologously express four different rice MT (OsMT) isoforms were analyzed for the accumulation of two forms of chromium, Cr3+ and Cr6+. RESULTS The results show that the transgenic bacteria were more tolerant than control cells when they were grown up in the medium comprising Cr(NO3)3.9H2O or Na2CrO4. The cells expressing OsMT1, OsMT2, OsMT3 and OsMT4 give rise to 6.5-, 2.7-, 5.5- and 2.1-fold improvements on the accumulation capacity for Cr3+ and 9-, 3-, 5- and 3- fold Cr6+ respectively compared with comparison to the control strain. Furthermore, the purified recombinant GST-OsMTs were tested for their binding ability to Cr+3 and Cr+6 in vitro. DISCUSSION The data show that the recombinant GST-OsMT1 and GST-OsMT2 were able to bind both Cr3+ and Cr6+, in vitro. However, their binding strength was low with respect to previous tested divalent ions like Cd2+.
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Affiliation(s)
- Azar Shahpiri
- Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Amir Mohammad Rahimi
- Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan 84156-83111, Iran
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Kumari S, Das S. Expression of metallothionein encoding gene bmtA in biofilm-forming marine bacterium Pseudomonas aeruginosa N6P6 and understanding its involvement in Pb(II) resistance and bioremediation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:28763-28774. [PMID: 31376126 DOI: 10.1007/s11356-019-05916-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 07/03/2019] [Indexed: 06/10/2023]
Abstract
The genetic basis and biochemical aspects of heavy metal endurance abilities have been precisely studied in planktonic bacteria; however, in nature, bacteria mostly grows as surface-attached communities called biofilms. A hallmark trait of biofilm is increased resistance to heavy metals compared with the resistance of planktonic bacteria. A proposed mechanism that contributes to this increased resistance is the enhanced expression of metal-resistant genes. bmtA gene coding for metallothionein protein is one such metal-resistant gene found in many bacterial spp. In the present study, lead (Pb) remediation potential of a biofilm-forming marine bacterium Pseudomonas aeruginosa N6P6 was explored. Biofilm-forming marine bacterium P. aeruginosa N6P6 possess bmtA gene and shows resistance towards many heavy metals, i.e., Pb, Cd, Hg, Cr, and Zn. The expression of metallothionein encoding gene bmtA is significantly high in 48-h-old biofilm culture (11. 4 fold) followed by 24-h-old biofilm culture of P. aeruginosa N6P6 (4.7 fold) (P < 0.05). However, in the case of planktonically grown culture of P. aeruginosa N6P6, the highest expression of bmtA gene was observed in 24-h-old culture. The expression of bmtA also increased significantly with increase in Pb concentration up to 800 ppm. CSLM analysis indicated significant reduction in the raw integrated density of biofilm-associated lipids and polysaccharides (PS) of P. aeruginosa N6P6 biofilm grown in Pb (sub-lethal concentration)-amended medium (P < 0.05), whereas no significant reduction was observed in the raw integrated density of EPS-associated protein. The role of bmtA gene as Pb(II)-resistant determinant was characterized by overexpressing the bmtA gene derived from P. aeruginosa N6P6 in Escherichia coli BL21(DE3). ESI-MS and SDS-PAGE analyses validated the presence of 11.5-kDa MT protein isolated from Pb(II)-induced recombinant E. coli BL21(DE3) harboring bmtA gene.
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Affiliation(s)
- Supriya Kumari
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769 008, India
| | - Surajit Das
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, Odisha, 769 008, India.
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Application of Microbial Cleaning Technology for Removal of Surface Contamination. DEVELOPMENTS IN SURFACE CONTAMINATION AND CLEANING: APPLICATIONS OF CLEANING TECHNIQUES 2019. [PMCID: PMC7149890 DOI: 10.1016/b978-0-12-815577-6.00015-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Microbial cleaning takes advantage of naturally-occurring microbes to remove a wide variety of contaminants from various surfaces. The method is based on the affinity of microbes for hydrocarbons that are digested, producing harmless carbon dioxide, water, and soluble fatty acids. The microbes are nonpathogenic and are safe to handle and dispose. The process is environmentally-friendly and is less expensive than solvent cleaning, but it is not applicable to high precision cleaning applications. Typical applications include parts washing; oil and grease removal from concrete and other floor surfaces, and from drains and grease traps; cleaning and disinfection in healthcare facilities; cleaning of historical artworks and structures; and household and institutional cleaning applications.
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Diep P, Mahadevan R, Yakunin AF. Heavy Metal Removal by Bioaccumulation Using Genetically Engineered Microorganisms. Front Bioeng Biotechnol 2018; 6:157. [PMID: 30420950 PMCID: PMC6215804 DOI: 10.3389/fbioe.2018.00157] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 10/09/2018] [Indexed: 11/25/2022] Open
Abstract
Wastewater effluents from mines and metal refineries are often contaminated with heavy metal ions, so they pose hazards to human and environmental health. Conventional technologies to remove heavy metal ions are well-established, but the most popular methods have drawbacks: chemical precipitation generates sludge waste, and activated carbon and ion exchange resins are made from unsustainable non-renewable resources. Using microbial biomass as the platform for heavy metal ion removal is an alternative method. Specifically, bioaccumulation is a natural biological phenomenon where microorganisms use proteins to uptake and sequester metal ions in the intracellular space to utilize in cellular processes (e.g., enzyme catalysis, signaling, stabilizing charges on biomolecules). Recombinant expression of these import-storage systems in genetically engineered microorganisms allows for enhanced uptake and sequestration of heavy metal ions. This has been studied for over two decades for bioremediative applications, but successful translation to industrial-scale processes is virtually non-existent. Meanwhile, demands for metal resources are increasing while discovery rates to supply primary grade ores are not. This review re-thinks how bioaccumulation can be used and proposes that it can be developed for bioextractive applications-the removal and recovery of heavy metal ions for downstream purification and refining, rather than disposal. This review consolidates previously tested import-storage systems into a biochemical framework and highlights efforts to overcome obstacles that limit industrial feasibility, thereby identifying gaps in knowledge and potential avenues of research in bioaccumulation.
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Affiliation(s)
| | | | - Alexander F. Yakunin
- BioZone - Centre for Applied Biosciences and Bioengineering, Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
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Alcántara C, Coll-Marqués JM, Jadán-Piedra C, Vélez D, Devesa V, Zúñiga M, Monedero V. Polyphosphate in Lactobacillus and Its Link to Stress Tolerance and Probiotic Properties. Front Microbiol 2018; 9:1944. [PMID: 30245671 PMCID: PMC6137179 DOI: 10.3389/fmicb.2018.01944] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 07/31/2018] [Indexed: 12/29/2022] Open
Abstract
The synthesis of the inorganic polymer polyphosphate (poly-P) in bacteria has been linked to stress survival and to the capacity of some strains to sequester heavy metals. In addition, synthesis of poly-P by certain strains of probiotic lactobacilli has been evidenced as a probiotic mechanism due to the homeostatic properties of this compound at the intestinal epithelium. We analyzed the link between poly-P synthesis, stress response, and mercury toxicity/accumulation by comparing wild-type strains of Lactobacillus and their corresponding mutants devoid of poly-P synthesis capacity (defective in the poly-P kinase, ppk, gene). Results showed that resistance to salt (NaCl) and acidic (pH 4) stresses upon ppk mutation was affected in Lactobacillus casei, while no effect was observed in two different Lactobacillus plantarum strains. Inorganic [Hg(II)] and organic (CH3Hg) mercury toxicity was generally increased upon ppk mutation, but no influence was seen on the capacity to retain both mercurial forms by the bacteria. Notwithstanding, the culture supernatants of ppk-defective L. plantarum strains possessed a diminished capacity to induce HSP27 expression, a marker for cell protection, in cultured Caco-2 cells compared to wild-type strains. In summary, our results illustrate that the role of poly-P in stress tolerance can vary between strains and they reinforce the idea of probiotic-derived poly-P as a molecule that modulates host-signaling pathways. They also question the relevance of this polymer to the capacity to retain mercury of probiotics.
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Affiliation(s)
- Cristina Alcántara
- Laboratory of Lactic Acid Bacteria and Probiotics, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - José M Coll-Marqués
- Laboratory of Lactic Acid Bacteria and Probiotics, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Carlos Jadán-Piedra
- Trace Elements Group, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Dinoraz Vélez
- Trace Elements Group, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Vicenta Devesa
- Trace Elements Group, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Manuel Zúñiga
- Laboratory of Lactic Acid Bacteria and Probiotics, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Vicente Monedero
- Laboratory of Lactic Acid Bacteria and Probiotics, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Valencia, Spain
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21
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The Construction of an Engineered Bacterial Strain and Its Application in Accumulating Mercury from Wastewater. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8091572] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
To remove organic and inorganic mercury from wastewater, an engineered bacterial strain, BL21-7, was constructed that contained the artificial operon P16S-g10-merT-merP-merB1-merB2-ppk-rpsT. For BL21-7, the minimum inhibitory concentrations of mercuric chloride, methylmercury chloride and phenylmercury chloride in Luria-Bertani (LB) medium were 100 µmol/L, 60 µmol/L and 80 µmol/L, respectively. After being cultured in three media (liquid LB containing 80 µmol/L mercuric chloride, 40 µmol/L methylmercury chloride or 60 µmol/L phenylmercury chloride) for 72 h, the engineered bacteria accumulated up to 70.5 ± 1.5 µmol/L, 33.5 ± 3.2 µmol/L and 45.3 ± 3.7 µmol/L of mercury, respectively. In the presence of 10 µmol/L Cd2+, 10 µmol/L Pb2+ or 10 µmol/L Cu2+, the accumulation of mercurial derivatives by BL21-7 was not affected. BL21-7 could accumulate mercury well in media with pH values ranging from 5 to 8 and it could work well at temperatures from 25 °C to 37 °C. After BL21-7 was added to wastewater and cultured for 24 h, approximately 43.7% of the Hg in the wastewater was removed.
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Bioaccumulation of Arsenic by Engineered Escherichia coli Cells Expressing Rice Metallothionein Isoforms. Curr Microbiol 2018; 75:1537-1542. [DOI: 10.1007/s00284-018-1556-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 08/22/2018] [Indexed: 10/28/2022]
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Kulakovskaya T. Inorganic polyphosphates and heavy metal resistance in microorganisms. World J Microbiol Biotechnol 2018; 34:139. [DOI: 10.1007/s11274-018-2523-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/23/2018] [Indexed: 12/11/2022]
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Gumulya Y, Boxall NJ, Khaleque HN, Santala V, Carlson RP, Kaksonen AH. In a quest for engineering acidophiles for biomining applications: challenges and opportunities. Genes (Basel) 2018; 9:E116. [PMID: 29466321 PMCID: PMC5852612 DOI: 10.3390/genes9020116] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 02/16/2018] [Accepted: 02/16/2018] [Indexed: 12/27/2022] Open
Abstract
Biomining with acidophilic microorganisms has been used at commercial scale for the extraction of metals from various sulfide ores. With metal demand and energy prices on the rise and the concurrent decline in quality and availability of mineral resources, there is an increasing interest in applying biomining technology, in particular for leaching metals from low grade minerals and wastes. However, bioprocessing is often hampered by the presence of inhibitory compounds that originate from complex ores. Synthetic biology could provide tools to improve the tolerance of biomining microbes to various stress factors that are present in biomining environments, which would ultimately increase bioleaching efficiency. This paper reviews the state-of-the-art tools to genetically modify acidophilic biomining microorganisms and the limitations of these tools. The first part of this review discusses resilience pathways that can be engineered in acidophiles to enhance their robustness and tolerance in harsh environments that prevail in bioleaching. The second part of the paper reviews the efforts that have been carried out towards engineering robust microorganisms and developing metabolic modelling tools. Novel synthetic biology tools have the potential to transform the biomining industry and facilitate the extraction of value from ores and wastes that cannot be processed with existing biomining microorganisms.
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Affiliation(s)
- Yosephine Gumulya
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Floreat WA 6014, Australia.
| | - Naomi J Boxall
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Floreat WA 6014, Australia.
| | - Himel N Khaleque
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Floreat WA 6014, Australia.
| | - Ville Santala
- Laboratory of Chemistry and Bioengineering, Tampere University of Technology (TUT), Tampere, 33101, Finland.
| | - Ross P Carlson
- Department of Chemical and Biological Engineering, Montana State University (MSU), Bozeman, MT 59717, USA.
| | - Anna H Kaksonen
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Floreat WA 6014, Australia.
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, WA 6009, Australia.
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25
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Mercury removal by engineered Escherichia coli cells expressing different rice metallothionein isoforms. ANN MICROBIOL 2018. [DOI: 10.1007/s13213-018-1326-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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26
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Mejias Carpio IE, Ansari A, Rodrigues DF. Relationship of Biodiversity with Heavy Metal Tolerance and Sorption Capacity: A Meta-Analysis Approach. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:184-194. [PMID: 29172474 DOI: 10.1021/acs.est.7b04131] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Microbial remediation of metals can alleviate the concerns of metal pollution in the environment. The microbial remediation, however, can be a complex process since microbial metal resistance and biodiversity can play a direct role in the bioremediation process. This study aims to understand the relationships among microbial metal resistance, biodiversity, and metal sorption capacity. Meta-analyses based on 735 literature data points of minimum inhibitory concentrations (MIC) of Plantae, Bacteria, and Fungi exposed to As, Cd, Cr Cu, Ni, Pb, and Zn showed that metal resistance depends on the microbial Kingdom and the type of heavy metal and that consortia are significantly more resistant to heavy metals than pure cultures. A similar meta-analysis comparing 517 MIC values from different bacterial genera (Bacillus, Cupriavidus, Klebsiella, Ochrobactrum, Paenibacillus, Pseudomonas, and Ralstonia) confirmed that metal tolerance depends on the type of genus. Another meta-analysis with 195 studies showed that the maximum sorption capacity is influenced by microbial Kingdoms, the type of biosorbent (whether consortia or pure cultures), and the type of metal. This study also suggests that bioremediation using microbial consortia is a valid option to reduce environmental metal contaminations.
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Affiliation(s)
- Isis E Mejias Carpio
- Department of Civil and Environmental Engineering. University of Houston , Houston, Texas 77004, United States
| | - Ali Ansari
- Department of Civil and Environmental Engineering. University of Houston , Houston, Texas 77004, United States
| | - Debora F Rodrigues
- Department of Civil and Environmental Engineering. University of Houston , Houston, Texas 77004, United States
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Alcántara C, Jadán-Piedra C, Vélez D, Devesa V, Zúñiga M, Monedero V. Characterization of the binding capacity of mercurial species in Lactobacillus strains. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2017; 97:5107-5113. [PMID: 28423187 DOI: 10.1002/jsfa.8388] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 03/22/2017] [Accepted: 04/12/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Metal sequestration by bacteria has been proposed as a strategy to counteract metal contamination in foodstuffs. Lactobacilli can interact with metals, although studies with important foodborne metals such as inorganic [Hg(II)] or organic (CH3 Hg) mercury are lacking. Lactobacilli were evaluated for their potential to bind these contaminants and the nature of the interaction was assessed by the use of metal competitors, chemical and enzymatical treatments, and mutants affected in the cell wall structure. RESULTS Lactobacillus strains efficiently bound Hg(II) and CH3 Hg. Mercury binding by Lactobacillus casei BL23 was independent of cell viability. In BL23, both forms of mercury were cell wall bound. Their interaction was not inhibited by cations and it was resistant to chelating agents and protein digestion. Lactobacillus casei mutants affected in genes involved in the modulation of the negative charge of the cell wall anionic polymer lipoteichoic acid showed increased mercury biosorption. In these mutants, mercury toxicity was enhanced compared to wild-type bacteria. These data suggest that lipoteichoic acid itself or the physicochemical characteristics that it confers to the cell wall play a major role in mercury complexation. CONCLUSION This is the first example of the biosorption of Hg(II) and CH3 Hg in lactobacilli and it represents a first step towards their possible use as agents for diminishing mercury bioaccessibility from food at the gastrointestinal tract. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Cristina Alcántara
- Laboratory of Lactic Acid Bacteria and Probiotics, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Paterna, Valencia, Spain
| | - Carlos Jadán-Piedra
- Laboratory of Trace Elements, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Paterna, Valencia, Spain
| | - Dinoraz Vélez
- Laboratory of Trace Elements, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Paterna, Valencia, Spain
| | - Vicenta Devesa
- Laboratory of Trace Elements, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Paterna, Valencia, Spain
| | - Manuel Zúñiga
- Laboratory of Lactic Acid Bacteria and Probiotics, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Paterna, Valencia, Spain
| | - Vicente Monedero
- Laboratory of Lactic Acid Bacteria and Probiotics, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Paterna, Valencia, Spain
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Numerical study of the effect of soft layer properties on bacterial electroporation. Bioelectrochemistry 2017; 123:261-272. [PMID: 29146422 DOI: 10.1016/j.bioelechem.2017.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 09/07/2017] [Accepted: 09/07/2017] [Indexed: 11/24/2022]
Abstract
We present a numerical model of electroporation in a gram-positive bacterium, which accounts for the presence of a negatively charged soft polyelectrolyte layer (which may include a periplasmic space, peptidoglycan layer, cilia, flagella, and other surface appendages) surrounding its plasma membrane. We model the ion transport within and outside the soft layer using the soft layer electrokinetics-based Poisson-Nernst-Planck formalism. Additionally, we model the electroporation dynamics on the plasma membrane using the pore nucleation-based electroporation formalism developed by Krassowska and Filev. We find that ion transport within the soft layer (surface conduction), which depends on the relative importance of the soft layer charged group concentration compared to the buffer concentration, significantly alters the transmembrane voltage across the plasma membrane and hence the pore characteristics. Our numerical simulations suggest that surface conduction significantly lowers the pore number in the plasma membrane. This observation is consistent with experimental studies that show that gram-positive bacteria, in general, have lower transformation efficiencies compared to gram-negative bacteria. Our studies highlight a strong dependence of bacterial electroporation on cell envelope properties and buffer conditions, which need to be taken into consideration when designing electroporation protocols.
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Effect of Cd 2+ and Cd 2+ /auxin mixtures on lipid monolayers – Model membrane studies on the role of auxins in phytoremediation of metal ions from contaminated environment. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1164-1171. [DOI: 10.1016/j.bbamem.2017.03.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/11/2017] [Accepted: 03/22/2017] [Indexed: 01/17/2023]
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Mahbub KR, Krishnan K, Andrews S, Venter H, Naidu R, Megharaj M. Bio-augmentation and nutrient amendment decrease concentration of mercury in contaminated soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 576:303-309. [PMID: 27788445 DOI: 10.1016/j.scitotenv.2016.10.083] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 10/11/2016] [Accepted: 10/11/2016] [Indexed: 06/06/2023]
Abstract
Four mercury (Hg) contaminated soils with different pH (7.6, 8.5, 4.2 and 7.02) and total organic carbon contents (2.1, 2.2, 4 and 0.9%) were subjected to bioremediation utilizing a Hg volatilizing bacterial strain Sphingobium SA2 and nutrient amendment. In a field with ~280mg/kgHg, 60% of Hg was removed by bio-augmentation in 7days, and the removal was improved when nutrients were added. Whereas in artificially spiked soils, with ~100mg/kgHg, removal due to bio-augmentation was 33 to 48% in 14days. In the field contaminated soil, nutrient amendment alone without bio-augmentation removed 50% of Hg in 28days. Nutrient amendment also had an impact on Hg remediation in the spiked soils, but the best results were obtained when the strain and nutrients both were applied. The development of longer root lengths from lettuce and cucumber seeds grown in the remediated soils confirmed that the soil quality improved after bioremediation. This study clearly demonstrates the potential of Hg-reducing bacteria in remediation of Hg-contaminated soils. However, it is desirable to trap the volatilized Hg for enhanced bioremediation.
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Affiliation(s)
- Khandaker Rayhan Mahbub
- Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE), Mawson Lakes, Adelaide, SA 5095, Australia.
| | - Kannan Krishnan
- Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE), Mawson Lakes, Adelaide, SA 5095, Australia
| | - Stuart Andrews
- University of South Australia, Adelaide, SA 5001, Australia
| | - Henrietta Venter
- School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA 5000, Australia
| | - Ravi Naidu
- Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE), Mawson Lakes, Adelaide, SA 5095, Australia
| | - Mallavarapu Megharaj
- Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE), Mawson Lakes, Adelaide, SA 5095, Australia
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Mahbub KR, Bahar MM, Labbate M, Krishnan K, Andrews S, Naidu R, Megharaj M. Bioremediation of mercury: not properly exploited in contaminated soils! Appl Microbiol Biotechnol 2017; 101:963-976. [DOI: 10.1007/s00253-016-8079-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 12/14/2016] [Indexed: 12/18/2022]
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Dash HR, Das S. Diversity, community structure, and bioremediation potential of mercury-resistant marine bacteria of estuarine and coastal environments of Odisha, India. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:6960-6971. [PMID: 26686519 DOI: 10.1007/s11356-015-5991-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 12/14/2015] [Indexed: 06/05/2023]
Abstract
Both point and non-point sources increase the pollution status of mercury and increase the population of mercury-resistant marine bacteria (MRMB). They can be targeted as the indicator organism to access marine mercury pollution, besides utilization in bioremediation. Thus, sediment and water samples were collected for 2 years (2010-2012) along Odisha coast of Bay of Bengal, India. Mercury content of the study sites varied from 0.47 to 0.99 ppb irrespective of the seasons of sampling. A strong positive correlation was observed between mercury content and MRMB population (P < 0.05) suggesting the utilization of these bacteria to assess the level of mercury pollution in the marine environment. Seventy-eight percent of the MRMB isolates were under the phylum Firmicutes, and 36 and 31% of them could resist mercury by mer operon-mediated volatilization and mercury biosorption, respectively. In addition, most of the isolates could resist a number of antibiotics and toxic metals. All the MRMB isolates possess the potential of growth and survival at cardinal pH (4-8), temperature (25-37 °C), and salinity (5-35 psu). Enterobacteria repetitive intergenic consensus (ERIC) and repetitive element palindromic PCR (REP-PCR) produced fingerprints corroborating the results of 16S rRNA gene sequencing. Fourier transform infrared (FTIR) spectral analysis also revealed strain-level speciation and phylogenetic relationships.
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Affiliation(s)
- Hirak R Dash
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India
| | - Surajit Das
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India.
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Genetic basis and importance of metal resistant genes in bacteria for bioremediation of contaminated environments with toxic metal pollutants. Appl Microbiol Biotechnol 2016; 100:2967-84. [PMID: 26860944 DOI: 10.1007/s00253-016-7364-4] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 01/26/2016] [Accepted: 01/28/2016] [Indexed: 10/22/2022]
Abstract
Metal pollution is one of the most persistent and complex environmental issues, causing threat to the ecosystem and human health. On exposure to several toxic metals such as arsenic, cadmium, chromium, copper, lead, and mercury, several bacteria has evolved with many metal-resistant genes as a means of their adaptation. These genes can be further exploited for bioremediation of the metal-contaminated environments. Many operon-clustered metal-resistant genes such as cadB, chrA, copAB, pbrA, merA, and NiCoT have been reported in bacterial systems for cadmium, chromium, copper, lead, mercury, and nickel resistance and detoxification, respectively. The field of environmental bioremediation has been ameliorated by exploiting diverse bacterial detoxification genes. Genetic engineering integrated with bioremediation assists in manipulation of bacterial genome which can enhance toxic metal detoxification that is not usually performed by normal bacteria. These techniques include genetic engineering with single genes or operons, pathway construction, and alternations of the sequences of existing genes. However, numerous facets of bacterial novel metal-resistant genes are yet to be explored for application in microbial bioremediation practices. This review describes the role of bacteria and their adaptive mechanisms for toxic metal detoxification and restoration of contaminated sites.
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Kane AL, Al-Shayeb B, Holec PV, Rajan S, Le Mieux NE, Heinsch SC, Psarska S, Aukema KG, Sarkar CA, Nater EA, Gralnick JA. Toward Bioremediation of Methylmercury Using Silica Encapsulated Escherichia coli Harboring the mer Operon. PLoS One 2016; 11:e0147036. [PMID: 26761437 PMCID: PMC4712050 DOI: 10.1371/journal.pone.0147036] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 12/28/2015] [Indexed: 11/18/2022] Open
Abstract
Mercury is a highly toxic heavy metal and the ability of the neurotoxin methylmercury to biomagnify in the food chain is a serious concern for both public and environmental health globally. Because thousands of tons of mercury are released into the environment each year, remediation strategies are urgently needed and prompted this study. To facilitate remediation of both organic and inorganic forms of mercury, Escherichia coli was engineered to harbor a subset of genes (merRTPAB) from the mercury resistance operon. Protein products of the mer operon enable transport of mercury into the cell, cleavage of organic C-Hg bonds, and subsequent reduction of ionic mercury to the less toxic elemental form, Hg(0). E. coli containing merRTPAB was then encapsulated in silica beads resulting in a biological-based filtration material. Performing encapsulation in aerated mineral oil yielded silica beads that were smooth, spherical, and similar in diameter. Following encapsulation, E. coli containing merRTPAB retained the ability to degrade methylmercury and performed similarly to non-encapsulated cells. Due to the versatility of both the engineered mercury resistant strain and silica bead technology, this study provides a strong foundation for use of the resulting biological-based filtration material for methylmercury remediation.
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Affiliation(s)
- Aunica L. Kane
- BioTechnology Institute, University of Minnesota-Twin Cities, St. Paul, Minnesota, United States of America
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota-Twin Cities, Minneapolis, Minnesota, United States of America
| | - Basem Al-Shayeb
- BioTechnology Institute, University of Minnesota-Twin Cities, St. Paul, Minnesota, United States of America
| | - Patrick V. Holec
- BioTechnology Institute, University of Minnesota-Twin Cities, St. Paul, Minnesota, United States of America
| | - Srijay Rajan
- BioTechnology Institute, University of Minnesota-Twin Cities, St. Paul, Minnesota, United States of America
| | - Nicholas E. Le Mieux
- BioTechnology Institute, University of Minnesota-Twin Cities, St. Paul, Minnesota, United States of America
| | - Stephen C. Heinsch
- BioTechnology Institute, University of Minnesota-Twin Cities, St. Paul, Minnesota, United States of America
| | - Sona Psarska
- Department of Soil, Water, and Climate, University of Minnesota-Twin Cities, St. Paul, Minnesota, United States of America
| | - Kelly G. Aukema
- BioTechnology Institute, University of Minnesota-Twin Cities, St. Paul, Minnesota, United States of America
| | - Casim A. Sarkar
- BioTechnology Institute, University of Minnesota-Twin Cities, St. Paul, Minnesota, United States of America
- Department of Biomedical Engineering, University of Minnesota-Twin Cities, Minneapolis, Minnesota, United States of America
| | - Edward A. Nater
- Department of Soil, Water, and Climate, University of Minnesota-Twin Cities, St. Paul, Minnesota, United States of America
| | - Jeffrey A. Gralnick
- BioTechnology Institute, University of Minnesota-Twin Cities, St. Paul, Minnesota, United States of America
- Department of Microbiology and Immunology, University of Minnesota-Twin Cities, Minneapolis, Minnesota, United States of America
- * E-mail:
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IRAWATI WAHYU, JAN NEXSON PARHUSIP ADOLF, NIDA SOPIAH RADEN. Heavy Metals Biosorption By Copper Resistant Bacteria of Acinetobacter Sp. IrC2. MICROBIOLOGY INDONESIA 2015. [DOI: 10.5454/mi.9.4.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Velásquez-Riaño M, Benavides-Otaya HD. Bioremediation techniques applied to aqueous media contaminated with mercury. Crit Rev Biotechnol 2015; 36:1124-1130. [PMID: 26482416 DOI: 10.3109/07388551.2015.1100156] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In recent years, the environmental and human health impacts of mercury contamination have driven the search for alternative, eco-efficient techniques different from the traditional physicochemical methods for treating this metal. One of these alternative processes is bioremediation. A comprehensive analysis of the different variables that can affect this process is presented. It focuses on determining the effectiveness of different techniques of bioremediation, with a specific consideration of three variables: the removal percentage, time needed for bioremediation and initial concentration of mercury to be treated in an aqueous medium.
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Gray MJ, Jakob U. Oxidative stress protection by polyphosphate--new roles for an old player. Curr Opin Microbiol 2015; 24:1-6. [PMID: 25589044 PMCID: PMC4380828 DOI: 10.1016/j.mib.2014.12.004] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/12/2014] [Accepted: 12/23/2014] [Indexed: 12/17/2022]
Abstract
Inorganic polyphosphate is a universally conserved biopolymer whose association with oxidative stress resistance has been documented in many species, but whose mode of action has been poorly understood. Here we review the recent discovery that polyphosphate functions as a protein-protective chaperone, examine the mechanisms by which polyphosphate-metal ion interactions reduce oxidative stress, and summarize polyphosphate's roles in regulating general stress response pathways. Given the simple chemical structure and ancient pedigree of polyphosphate, these diverse mechanisms are likely to be broadly relevant in many organisms, from bacteria to mammalian cells.
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Affiliation(s)
- Michael J Gray
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Ursula Jakob
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA; Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA.
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Drewniak L, Ciezkowska M, Radlinska M, Sklodowska A. Construction of the recombinant broad-host-range plasmids providing their bacterial hosts arsenic resistance and arsenite oxidation ability. J Biotechnol 2015; 196-197:42-51. [PMID: 25617684 DOI: 10.1016/j.jbiotec.2015.01.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 01/12/2015] [Accepted: 01/16/2015] [Indexed: 11/17/2022]
Abstract
The plasmid pSinA of Sinorhizobium sp. M14 was used as a source of functional phenotypic modules, encoding proteins involved in arsenite oxidation and arsenic resistance, to obtain recombinant broad-host-range plasmids providing their bacterial hosts arsenic resistance and arsenite oxidative ability. An arsenite oxidation module was cloned into pBBR1MCS-2 vector yielding plasmid vector pAIO1, while an arsenic resistance module was cloned into pCM62 vector yielding plasmid pARS1. Both plasmid constructs were introduced (separately and together) into the cells of phylogenetically distant (representing Alpha-, Beta-, and Gammaproteobacteria) and physiologically diversified (unable to oxidize arsenite and susceptible/resistant to arsenite and arsenate) bacteria. Functional analysis of the modified strains showed that: (i) the plasmid pARS1 can be used for the construction of strains with an increased resistance to arsenite [up to 20mM of As(III), (ii) the presence of the plasmid pAIO1 in bacteria previously unable to oxidize As(III) to As(V), contributes to the acquisition of arsenite oxidation abilities by these cells, (iii) the highest arsenite utilization rate are observed in the culture of strains harbouring both the plasmids pAIO1 and pARS1, (iv) the strains harbouring the plasmid pAIO1 were able to grow on arsenic-contaminated mine waters (∼ 3.0 mg As L(-1)) without any supplementation.
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Affiliation(s)
- Lukasz Drewniak
- Laboratory of Environmental Pollution Analysis, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland.
| | - Martyna Ciezkowska
- Laboratory of Environmental Pollution Analysis, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | - Monika Radlinska
- Department of Virology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | - Aleksandra Sklodowska
- Laboratory of Environmental Pollution Analysis, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
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Duprey A, Chansavang V, Frémion F, Gonthier C, Louis Y, Lejeune P, Springer F, Desjardin V, Rodrigue A, Dorel C. "NiCo Buster": engineering E. coli for fast and efficient capture of cobalt and nickel. J Biol Eng 2014; 8:19. [PMID: 25104972 PMCID: PMC4124493 DOI: 10.1186/1754-1611-8-19] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 07/13/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Metal contamination is widespread and results from natural geogenic and constantly increasing anthropogenic sources (mainly mining and extraction activities, electroplating, battery and steel manufacturing or metal finishing). Consequently, there is a growing need for methods to detoxify polluted ecosystems. Industrial wastewater, surface water and ground water need to be decontaminated to alleviate the contamination of soils and sediments and, ultimately, the human food chain. In nuclear power plants, radioactive metals are produced; these metals need to be removed from effluents before they are released into the environment, not only for pollution prevention but also for waste minimization. Many physicochemical methods have been developed for metal removal from aqueous solutions, including chemical coagulation, adsorption, extraction, ion exchange and membrane separation; however, these methods are generally not metal selective. Bacteria, because they contain metal transporters, provide a potentially competitive alternative to the current use of expensive and high-volume ion-exchange resins. RESULTS The feasibility of using bacterial biofilters as efficient tools for nickel and cobalt ions specific remediation was investigated. Among the factors susceptible to genetic modification in Escherichia coli, specific efflux and sequestration systems were engineered to improve its metal sequestration abilities. Genomic suppression of the RcnA nickel (Ni) and cobalt (Co) efflux system was combined with the plasmid-controlled expression of a genetically improved version of a specific metallic transporter, NiCoT, which originates from Novosphingobium aromaticivorans. The resulting strain exhibited enhanced nickel (II) and cobalt (II) uptake, with a maximum metal ion accumulation of 6 mg/g bacterial dry weight during 10 min of treatment. A synthetic adherence operon was successfully introduced into the plasmid carrying the improved NiCoT transporter, conferring the ability to form thick biofilm structures, especially when exposed to nickel and cobalt metallic compounds. CONCLUSIONS This study demonstrates the efficient use of genetic engineering to increase metal sequestration and biofilm formation by E. coli. This method allows Co and Ni contaminants to be sequestered while spatially confining the bacteria to an abiotic support. Biofiltration of nickel (II) and cobalt (II) by immobilized cells is therefore a promising option for treating these contaminants at an industrial scale.
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Affiliation(s)
- Alexandre Duprey
- iGEM team INSA Lyon, Plateforme de Biologie de Synthèse, Département Biosciences, INSA Lyon, 69621 Villeurbanne Cedex, France.,Université de Lyon, INSA-Lyon, Université Claude Bernard Lyon I, CNRS, MAP, UMR5240, Villeurbanne F-69621, France
| | - Viviane Chansavang
- iGEM team INSA Lyon, Plateforme de Biologie de Synthèse, Département Biosciences, INSA Lyon, 69621 Villeurbanne Cedex, France
| | - Franck Frémion
- iGEM team INSA Lyon, Plateforme de Biologie de Synthèse, Département Biosciences, INSA Lyon, 69621 Villeurbanne Cedex, France
| | - Clémence Gonthier
- iGEM team INSA Lyon, Plateforme de Biologie de Synthèse, Département Biosciences, INSA Lyon, 69621 Villeurbanne Cedex, France
| | - Yoann Louis
- Université de Lyon, INSA-Lyon, LGCIE, Villeurbanne F-69621, France
| | - Philippe Lejeune
- Université de Lyon, INSA-Lyon, Université Claude Bernard Lyon I, CNRS, MAP, UMR5240, Villeurbanne F-69621, France
| | - Fanny Springer
- Université de Lyon, INSA-Lyon, LGCIE, Villeurbanne F-69621, France
| | | | - Agnès Rodrigue
- Université de Lyon, INSA-Lyon, Université Claude Bernard Lyon I, CNRS, MAP, UMR5240, Villeurbanne F-69621, France
| | - Corinne Dorel
- Université de Lyon, INSA-Lyon, LGCIE, Villeurbanne F-69621, France
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Accumulation of polyphosphate in Lactobacillus spp. and its involvement in stress resistance. Appl Environ Microbiol 2013; 80:1650-9. [PMID: 24375133 DOI: 10.1128/aem.03997-13] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Polyphosphate (poly-P) is a polymer of phosphate residues synthesized and in some cases accumulated by microorganisms, where it plays crucial physiological roles such as the participation in the response to nutritional stringencies and environmental stresses. Poly-P metabolism has received little attention in Lactobacillus, a genus of lactic acid bacteria of relevance for food production and health of humans and animals. We show that among 34 strains of Lactobacillus, 18 of them accumulated intracellular poly-P granules, as revealed by specific staining and electron microscopy. Poly-P accumulation was generally dependent on the presence of elevated phosphate concentrations in the culture medium, and it correlated with the presence of polyphosphate kinase (ppk) genes in the genomes. The ppk gene from Lactobacillus displayed a genetic arrangement in which it was flanked by two genes encoding exopolyphosphatases of the Ppx-GppA family. The ppk functionality was corroborated by its disruption (LCABL_27820 gene) in Lactobacillus casei BL23 strain. The constructed ppk mutant showed a lack of intracellular poly-P granules and a drastic reduction in poly-P synthesis. Resistance to several stresses was tested in the ppk-disrupted strain, showing that it presented a diminished growth under high-salt or low-pH conditions and an increased sensitivity to oxidative stress. These results show that poly-P accumulation is a characteristic of some strains of lactobacilli and may thus play important roles in the physiology of these microorganisms.
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Zhang Y, Liu J, Zhou Y, Gong T, Wang J, Ge Y. Enhanced phytoremediation of mixed heavy metal (mercury)-organic pollutants (trichloroethylene) with transgenic alfalfa co-expressing glutathione S-transferase and human P450 2E1. JOURNAL OF HAZARDOUS MATERIALS 2013; 260:1100-1107. [PMID: 23933506 DOI: 10.1016/j.jhazmat.2013.06.065] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 03/22/2013] [Accepted: 06/25/2013] [Indexed: 06/02/2023]
Abstract
Soil contamination is a global environmental problem and many efforts have been made to find efficient remediation methods over the last decade. Moreover, remediation of mixed contaminated soils are more difficult. In the present study, transgenic alfalfa plants pKHCG co-expressing glutathione S-transferase (GST) and human P450 2E1 (CYP2E1) genes were used for phytoremediation of mixed mercury (Hg)-trichloroethylene (TCE) contaminants. Simultaneous expression of GST and CYP2E1 may produce a significant synergistic effect, and leads to improved resistance and accumulation to heavy metal-organic complex contaminants. Based on the tolerance and accumulation assays, pKHCG transgenic plants were more resistant to Hg/TCE complex pollutants and many folds higher in Hg/TCE-accumulation than the non-transgenic control plants in mixed contaminated soil. It is confirmed that GST and CYP2E1 co-expression may be a useful strategy to help achieve mixed heavy metal-organic pollutants phytoremediation.
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Affiliation(s)
- Yuanyuan Zhang
- Department of Pharmaceutics, Qingdao University of Science and Technology, 53 Zhengzhou Road, PO Box 70, Qingdao 266042, China
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Chen Z, Pan Y, Wang S, Ding Y, Yang W, Zhu C. Overexpression of a protein disulfide isomerase-like protein from Methanothermobacter thermoautotrophicum enhances mercury tolerance in transgenic rice. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 197:10-20. [PMID: 23116667 DOI: 10.1016/j.plantsci.2012.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 07/28/2012] [Accepted: 08/03/2012] [Indexed: 05/07/2023]
Abstract
MTH1745, from thermophilic archaea Methanothermobacter thermoautotrophicum, is a protein disulfide isomerase-like protein (PDIL) with a chaperone function and disulfide isomerase activity. Mercuric cations have a high affinity for sulfhydryl groups and consequently inhibit plant growth. Disulfide compounds (e.g., copper-zinc superoxide dismutase, Cu/Zn SOD) and sulfhydryl compounds (e.g., glutathione, phytochelatins, and metallothioneins) play important roles in mercury (Hg) response. To study the relationship between Hg detoxification and PDILs, we overexpressed MTH1745 in Oryza sativa L. cv. Nipponbare by Agrobacterium-mediated transformation. The transgenic rice seedlings displayed Hg tolerance with obvious phenotypes and more effective photosynthesis compared to wild-type plants. Furthermore, lower levels of superoxide anion radicals, hydrogen peroxide, and malondialdehyde were observed in leaves or roots of transgenic plants. Antioxidant enzyme activities of superoxide dismutase and peroxidase were notably higher in transgenic seedlings under different concentrations of mercuric chloride. Moreover, increased content of non-protein thiols, reduced glutathione (GSH), and GSH/GSSG (GSSG, oxidized glutathione) ratio were also observed in the detoxification of Hg. These results indicated that heterologous expression of a PDIL from extremophiles in rice could protect the synthesis, increase stability of proteins, and enhance Hg tolerance in rice.
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Affiliation(s)
- Zhen Chen
- College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China
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