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Li Y, Yu Y, Yang X, Pat-Espadas AM, Vinuesa P, Herzberg M, Chen J, Rosen BP, Feng R, Rensing C. Adaptation to metal(loid)s in strain Mucilaginibacter rubeus P2 involves novel arsenic resistance genes and mechanisms. JOURNAL OF HAZARDOUS MATERIALS 2024; 462:132796. [PMID: 37865075 PMCID: PMC10699512 DOI: 10.1016/j.jhazmat.2023.132796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 09/30/2023] [Accepted: 10/14/2023] [Indexed: 10/23/2023]
Abstract
Arsenic is a ubiquitous environmental toxi substance that affects human health. Compared to inorganic arsenicals, reduced organoarsenicals are more toxic, and some of them are recognized as antibiotics, such as methylarsenite [MAs(III)] and arsinothricin (2-amino-4-(hydroxymethylarsinoyl)butanoate, or AST). To date, organoarsenicals such as MAs(V) and roxarsone [Rox(V)] are still used in agriculture and animal husbandry. How bacteria deal with both inorganic and organoarsenic species is unclear. Recently, we identified an environmental isolate Mucilaginibacter rubeus P2 that has adapted to high arsenic and antinomy levels by triplicating an arsR-mrarsUBact-arsN-arsC-(arsRhp)-hp-acr3-mrme1Bact-mrme2Bactgene cluster. Heterologous expression of mrarsMBact, mrarsUBact, mrme1Bact and mrme2Bact, encoding putative arsenic resistance determinants, in the arsenic hypersensitive strain Escherichia coli AW3110 conferred resistance to As(III), As(V), MAs(III) or Rox(III). Our data suggest that metalloid exposure promotes plasticity in arsenic resistance systems, enhancing host organism adaptation to metalloid stress.
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Affiliation(s)
- Yuanping Li
- College of Tea and Food, Wuyi University, Wuyishan, China
| | - Yanshuang Yu
- Institute of Environmental Microbiology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaojun Yang
- College of Ecology and Resource Engineering, Wuyi University, Wuyishan, China
| | - Aurora M Pat-Espadas
- CONACYT-Institute of Geology, Estación Regional del Noroeste, Universidad Nacional Autónoma de México, Luis Donaldo Colosio s/n, Hermosillo, Sonora, Mexico
| | - Pablo Vinuesa
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Martin Herzberg
- Molecular Microbiology, Institute for Biology/Microbiology, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120 Halle, Germany
| | - Jian Chen
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States
| | - Barry P Rosen
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States
| | - Renwei Feng
- Institute of Environmental Microbiology, Fujian Agriculture and Forestry University, Fuzhou, China.
| | - Christopher Rensing
- Institute of Environmental Microbiology, Fujian Agriculture and Forestry University, Fuzhou, China.
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2
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Liu S, Zeng J, Yu H, Wang C, Yang Y, Wang J, He Z, Yan Q. Antimony efflux underpins phosphorus cycling and resistance of phosphate-solubilizing bacteria in mining soils. THE ISME JOURNAL 2023:10.1038/s41396-023-01445-6. [PMID: 37270585 DOI: 10.1038/s41396-023-01445-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 05/14/2023] [Accepted: 05/24/2023] [Indexed: 06/05/2023]
Abstract
Microorganisms play crucial roles in phosphorus (P) turnover and P bioavailability increases in heavy metal-contaminated soils. However, microbially driven P-cycling processes and mechanisms of their resistance to heavy metal contaminants remain poorly understood. Here, we examined the possible survival strategies of P-cycling microorganisms in horizontal and vertical soil samples from the world's largest antimony (Sb) mining site, which is located in Xikuangshan, China. We found that total soil Sb and pH were the primary factors affecting bacterial community diversity, structure and P-cycling traits. Bacteria with the gcd gene, encoding an enzyme responsible for gluconic acid production, largely correlated with inorganic phosphate (Pi) solubilization and significantly enhanced soil P bioavailability. Among the 106 nearly complete bacterial metagenome-assembled genomes (MAGs) recovered, 60.4% carried the gcd gene. Pi transportation systems encoded by pit or pstSCAB were widely present in gcd-harboring bacteria, and 43.8% of the gcd-harboring bacteria also carried the acr3 gene encoding an Sb efflux pump. Phylogenetic and potential horizontal gene transfer (HGT) analyses of acr3 indicated that Sb efflux could be a dominant resistance mechanism, and two gcd-harboring MAGs appeared to acquire acr3 through HGT. The results indicated that Sb efflux could enhance P cycling and heavy metal resistance in Pi-solubilizing bacteria in mining soils. This study provides novel strategies for managing and remediating heavy metal-contaminated ecosystems.
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Affiliation(s)
- Shengwei Liu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou, 510006, China
| | - Jiaxiong Zeng
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou, 510006, China
| | - Huang Yu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou, 510006, China
| | - Cheng Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yunfeng Yang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 100084, Beijing, China
| | - Jianjun Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Zhili He
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou, 510006, China
| | - Qingyun Yan
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou, 510006, China.
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3
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Mizio K, Wawrzycka D, Staszewski J, Wysocki R, Maciaszczyk-Dziubinska E. Identification of amino acid substitutions that toggle substrate selectivity of the yeast arsenite transporter Acr3. JOURNAL OF HAZARDOUS MATERIALS 2023; 456:131653. [PMID: 37224717 DOI: 10.1016/j.jhazmat.2023.131653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/03/2023] [Accepted: 05/15/2023] [Indexed: 05/26/2023]
Abstract
The Acr3 protein family plays a crucial role in metalloid detoxification and includes members from bacteria to higher plants. Most of the Acr3 transporters studied so far are specific for arsenite, whereas Acr3 from budding yeast also shows some capacity to transport antimonite. However, the molecular basis of Acr3 substrate specificity remains poorly understood. By analyzing randomly generated and rationally designed yeast Acr3 variants, critical residues determining substrate specificity were identified for the first time. Replacement of Val173 with Ala abolished antimonite transport without affecting arsenite extrusion. In contrast, substitution of Glu353 with Asp resulted in a loss of arsenite transport activity and a concomitant increase in antimonite translocation capacity. Importantly, Val173 is located close to the hypothetical substrate binding site, whereas Glu353 has been proposed to participate in substrate binding. Identification of key residues conferring substrate selectivity provides a valuable starting point for further studies of the Acr3 family and may have implications for the development of biotechnological applications in metalloid remediation. Moreover, our data contribute to understanding why members of the Acr3 family evolved as arsenite-specific transporters in an environment of ubiquitously present arsenic and trace amounts of antimony.
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Affiliation(s)
- Katarzyna Mizio
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, 50-328 Wroclaw, Poland
| | - Donata Wawrzycka
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, 50-328 Wroclaw, Poland
| | - Jacek Staszewski
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, 50-328 Wroclaw, Poland
| | - Robert Wysocki
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, 50-328 Wroclaw, Poland
| | - Ewa Maciaszczyk-Dziubinska
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, 50-328 Wroclaw, Poland.
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4
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Deng R, Chen Y, Deng X, Huang Z, Zhou S, Ren B, Jin G, Hursthouse A. A Critical Review of Resistance and Oxidation Mechanisms of Sb-Oxidizing Bacteria for the Bioremediation of Sb(III) Pollution. Front Microbiol 2021; 12:738596. [PMID: 34557178 PMCID: PMC8453088 DOI: 10.3389/fmicb.2021.738596] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 07/30/2021] [Indexed: 12/03/2022] Open
Abstract
Antimony (Sb) is a priority pollutant in many countries and regions due to its chronic toxicity and potential carcinogenicity. Elevated concentrations of Sb in the environmental originating from mining and other anthropogenic sources are of particular global concern, so the prevention and control of the source of pollution and environment remediation are urgent. It is widely accepted that indigenous microbes play an important role in Sb speciation, mobility, bioavailability, and fate in the natural environment. Especially, antimony-oxidizing bacteria can promote the release of antimony from ore deposits to the wider environment. However, it can also oxidize the more toxic antimonite [Sb(III)] to the less-toxic antimonate [Sb(V)], which is considered as a potentially environmentally friendly and efficient remediation technology for Sb pollution. Therefore, understanding its biological oxidation mechanism has great practical significance to protect environment and human health. This paper reviews studies of the isolation, identification, diversity, Sb(III) resistance mechanisms, Sb(III) oxidation characteristics and mechanism and potential application of Sb-oxidizing bacteria. The aim is to provide a theoretical basis and reference for the diversity and metabolic mechanism of Sb-oxidizing bacteria, the prevention and control of Sb pollution sources, and the application of environment treatment for Sb pollution.
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Affiliation(s)
- Renjian Deng
- School of Civil Engineering, Hunan University of Science and Technology, Xiangtan, China
| | - Yilin Chen
- School of Civil Engineering, Hunan University of Science and Technology, Xiangtan, China
| | - Xinpin Deng
- Hunan 402 Geological Prospecting Part, Changsha, China
| | - Zhongjie Huang
- School of Civil Engineering, Hunan University of Science and Technology, Xiangtan, China
| | - Saijun Zhou
- School of Civil Engineering, Hunan University of Science and Technology, Xiangtan, China
| | - Bozhi Ren
- School of Civil Engineering, Hunan University of Science and Technology, Xiangtan, China
| | - Guizhong Jin
- Hsikwangshan Twinkling Star Co., Ltd., Lengshuijiang, China
| | - Andrew Hursthouse
- School of Civil Engineering, Hunan University of Science and Technology, Xiangtan, China
- School of Computing, Engineering and Physical Sciences, The University of the West of Scotland, Paisley, United Kingdom
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5
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Rawle R, Saley TC, Kang YS, Wang Q, Walk S, Bothner B, McDermott TR. Introducing the ArsR-Regulated Arsenic Stimulon. Front Microbiol 2021; 12:630562. [PMID: 33746923 PMCID: PMC7965956 DOI: 10.3389/fmicb.2021.630562] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/18/2021] [Indexed: 12/21/2022] Open
Abstract
The microbial ars operon encodes the primary bacterial defense response to the environmental toxicant, arsenic. An important component of this operon is the arsR gene, which encodes ArsR, a member of the family of proteins categorized as DNA-binding transcriptional repressors. As currently documented, ArsR regulates its own expression as well as other genes in the same ars operon. This study examined the roles of four ArsR proteins in the well-developed model Gram-negative bacterium Agrobacterium tumefaciens 5A. RNASeq was used to compare and characterize gene expression profiles in ± arsenite-treated cells of the wild-type strain and in four different arsR mutants. We report that ArsR-controlled transcription regulation is truly global, extending well beyond the current ars operon model, and includes both repression as well as apparent activation effects. Many cellular functions are significantly influenced, including arsenic resistance, phosphate acquisition/metabolism, sugar transport, chemotaxis, copper tolerance, iron homeostasis, and many others. While there is evidence of some regulatory overlap, each ArsR exhibits its own regulatory profile. Furthermore, evidence of a regulatory hierarchy was observed; i.e. ArsR1 represses arsR4, ArsR4 activates arsR2, and ArsR2 represses arsR3. Additionally and unexpectedly, aioB (arsenite oxidase small subunit) expression was shown to be under partial positive control by ArsR2 and ArsR4. Summarizing, this study demonstrates the regulatory portfolio of arsenite-activated ArsR proteins and includes essentially all major cellular functions. The broad bandwidth of arsenic effects on microbial metabolism assists in explaining and understanding the full impact of arsenic in natural ecosystems, including the mammalian gut.
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Affiliation(s)
- Rachel Rawle
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Tara C Saley
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, United States
| | - Yoon-Suk Kang
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, United States
| | - Qian Wang
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, United States
| | - Seth Walk
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, United States
| | - Timothy R McDermott
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, United States
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6
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Durante-Rodríguez G, Fernández-Llamosas H, Alonso-Fernandes E, Fernández-Muñiz MN, Muñoz-Olivas R, Díaz E, Carmona M. ArxA From Azoarcus sp. CIB, an Anaerobic Arsenite Oxidase From an Obligate Heterotrophic and Mesophilic Bacterium. Front Microbiol 2019; 10:1699. [PMID: 31417512 PMCID: PMC6683785 DOI: 10.3389/fmicb.2019.01699] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 07/10/2019] [Indexed: 11/13/2022] Open
Abstract
Arsenic is a toxic element widely distributed in nature, but numerous bacteria are able to resist its toxicity mainly through the ars genes encoding an arsenate reductase and an arsenite efflux pump. Some “arsenotrophic” bacteria are also able to use arsenite as energy supplier during autotrophic growth by coupling anaerobic arsenite oxidation via the arx gene products to nitrate respiration or photosynthesis. Here, we have demonstrated that Azoarcus sp. CIB, a facultative anaerobic β-proteobacterium, is able to resist arsenic oxyanions both under aerobic and anaerobic conditions. Genome mining, gene expression, and mutagenesis studies revealed the presence of a genomic island that harbors the ars and arx clusters involved in arsenic resistance in strain CIB. Orthologous ars clusters are widely distributed in the genomes of sequenced Azoarcus strains. Interestingly, genetic and metabolic approaches showed that the arx cluster of the CIB strain encodes an anaerobic arsenite oxidase also involved in the use of arsenite as energy source. Hence, Azoarcus sp. CIB represents the prototype of an obligate heterotrophic bacterium able to use arsenite as an extra-energy source for anaerobic cell growth. The arsenic island of strain CIB supports the notion that metabolic and energetic skills can be gained by genetic mobile elements.
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Affiliation(s)
| | | | - Elena Alonso-Fernandes
- Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas-CSIC, Madrid, Spain
| | | | - Riansares Muñoz-Olivas
- Departamento de Química Analítica, Facultad de Químicas, Universidad Complutense Madrid, Madrid, Spain
| | - Eduardo Díaz
- Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas-CSIC, Madrid, Spain
| | - Manuel Carmona
- Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas-CSIC, Madrid, Spain
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7
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Efflux proteins MacAB confer resistance to arsenite and penicillin/macrolide-type antibiotics in Agrobacterium tumefaciens 5A. World J Microbiol Biotechnol 2019; 35:115. [PMID: 31332542 DOI: 10.1007/s11274-019-2689-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 07/07/2019] [Indexed: 10/26/2022]
Abstract
Antibiotic and arsenic (As) contaminations are worldwide public health problems. Previously, the bacterial ABC-type efflux protein MacAB reportedly conferred resistance to macrolide-type antibiotics but not to other metal(loid)s. In this study, the roles of MacAB for the co-resistance of different antibiotics and several metal(loid)s were analyzed in Agrobacterium tumefaciens 5A, a strain resistant to arsenite [As(III)] and several types of antibiotics. The macA and macB genes were cotranscribed, and macB was deleted in A. tumefaciens 5A and heterologously expressed in Escherichia coli AW3110 and E. coli S17-1. Compared to the wild-type strain 5A, the macB deletion strain reduced bacterial resistance levels to several macrolide-type and penicillin-type antibiotics but not to cephalosporin-type antibiotics. In addition, the macB deletion strain showed lower resistance to As(III) but not to arsenate [As(V)], antimonite [Sb(III)] and cadmium chloride [Cd(II)]. The mutant strain 5A-ΔmacB cells accumulated more As(III) than the cells of the wild-type. Furthermore, heterologous expression of MacAB in E. coli S17-1 showed that MacAB was essential for resistance to macrolide, several penicillin-type antibiotics and As(III) but not to As(V). Heterologous expression of MacAB in E. coli AW3110 reduced the cellular accumulation of As(III) but not of As(V), indicating that MacAB is responsible for the efflux of As(III). These results demonstrated that, in addition to macrolide-type antibiotics, MacAB also conferred resistance to penicillin-type antibiotics and As(III) by extruding them out of cells. This finding contributes to a better understanding of the bacterial resistance mechanisms of antibiotics and metal(loid)s.
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8
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Rawle RA, Kang YS, Bothner B, Wang G, McDermott TR. Transcriptomics analysis defines global cellular response of Agrobacterium tumefaciens 5A to arsenite exposure regulated through the histidine kinases PhoR and AioS. Environ Microbiol 2019; 21:2659-2676. [PMID: 30815967 DOI: 10.1111/1462-2920.14577] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 01/28/2019] [Accepted: 02/26/2019] [Indexed: 11/29/2022]
Abstract
In environments where arsenic and microbes coexist, microbes are the principal drivers of arsenic speciation, which directly affects bioavailability, toxicity and bioaccumulation. Speciation reactions influence arsenic behaviour in environmental systems, directly affecting human and agricultural exposures. Arsenite oxidation decreases arsenic toxicity and mobility in the environment, and therefore understanding its regulation and overall influence on cellular metabolism is of significant interest. The arsenite oxidase (AioBA) is regulated by a three-component signal transduction system AioXSR, which is in turn regulated by the phosphate stress response, with PhoR acting as the master regulator. Using RNA-sequencing, we characterized the global effects of arsenite on gene expression in Agrobacterium tumefaciens 5A. To further elucidate regulatory controls, mutant strains for histidine kinases PhoR and AioS were employed, and illustrate that in addition to arsenic metabolism, a host of other functional responses are regulated in parallel. Impacted functions include arsenic and phosphate metabolism, carbohydrate metabolism, solute transport systems and iron metabolism, in addition to others. These findings contribute significantly to the current understanding of the metabolic impact and genetic circuitry involved during arsenite exposure in bacteria. This informs how arsenic contamination will impact microbial activities involving several biogeochemical cycles in nature.
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Affiliation(s)
- Rachel A Rawle
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Yoon-Suk Kang
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Timothy R McDermott
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA
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9
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Xia X, Li J, Zhou Z, Wang D, Huang J, Wang G. High-quality-draft genome sequence of the multiple heavy metal resistant bacterium Pseudaminobacter manganicus JH-7 T. Stand Genomic Sci 2018; 13:29. [PMID: 30386456 PMCID: PMC6203287 DOI: 10.1186/s40793-018-0330-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 09/28/2018] [Indexed: 01/01/2023] Open
Abstract
Pseudaminobacter manganicus JH-7T (= KCTC 52258T = CCTCC AB 2016107T) is a Gram-staining-negative, aerobic and non-motile strain that was isolated from a manganese mine. The strain JH-7T shows multiple heavy metal resistance and can effectively remove Mn2+ and Cd2+. In addition, it is able to produce exopolysaccharides (EPS), which may contribute to metal remove/adsorption. Thus, strain JH-7T shows a great potential in bioremediation of heavy metal-contaminated environment. In this study, we report the draft genomic sequence of P. manganicus JH-7T and compare it to related genomes. Strain JH-7T has a 4,842,937 bp genome size with a G + C content of 61.2%, containing 4504 protein-coding genes and 71 RNA genes. A large number of putative genes associated with heavy metal resistance and EPS synthesis are found in the genome.
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Affiliation(s)
- Xian Xia
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Jiahong Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Zijie Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Dan Wang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Jing Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
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10
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Han YH, Jia MR, Liu X, Zhu Y, Cao Y, Chen DL, Chen Y, Ma LQ. Bacteria from the rhizosphere and tissues of As-hyperaccumulator Pteris vittata and their role in arsenic transformation. CHEMOSPHERE 2017; 186:599-606. [PMID: 28813694 DOI: 10.1016/j.chemosphere.2017.08.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/28/2017] [Accepted: 08/08/2017] [Indexed: 06/07/2023]
Abstract
Arsenic (As)-resistant bacteria are abundant in the rhizosphere and tissues of As-hyperaccumulator Pteris vittata. However, little is known about their roles in As transformation and As uptake in P. vittata. In this study, the impacts of P. vittata tissue extracts with or without surface sterilization on As transformation in solutions containing 100 μg L-1 AsIII or AsV were investigated. After 48 h incubation, the sterilized and unsterilized root extracts resulted in 45% and 73% oxidation of AsIII, indicating a role of both rhizobacteria and endobacteria. In contrast, AsV reduction was only found in rhizome and frond extracts at 3.7-24% of AsV. A total of 37 strains were isolated from the tissue extracts, which are classified into 18 species based on morphology and 16S rRNA. Phylogenic analysis showed that ∼44% isolates were Firmicutes and others were Proteobacteria except for one strain belonging to Bacteroidetes. While most endobacteria were Firmicutes, most rhizobacteria were Proteobacteria. All isolated bacteria belonged to AsV reducers except for an As-sensitive strain and one AsIII- oxidizer PVR-YHB6-1. Since As transformation was not observed in solutions after filtrating or boiling, we concluded that both rhizobacteria and endobacteria were involved in As transformation in the rhizosphere and tissues of P. vittata.
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Affiliation(s)
- Yong-He Han
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210023, China; Quangang Petrochemical Research Institute, Fujian Normal University, Quanzhou, Fujian, 326801, China
| | - Meng-Ru Jia
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210023, China
| | - Xue Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210023, China
| | - Ying Zhu
- Fujian Center for Disease Control & Prevention, Fuzhou, Fujian, 350001, China
| | - Yue Cao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210023, China
| | - Deng-Long Chen
- Quangang Petrochemical Research Institute, Fujian Normal University, Quanzhou, Fujian, 326801, China
| | - Yanshan Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210023, China.
| | - Lena Q Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210023, China; Soil and Water Sciences Department, University of Florida, Gainesville, FL 32611, United States.
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11
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Li J, Yang B, Shi M, Yuan K, Guo W, Wang Q, Wang G. Abiotic and biotic factors responsible for antimonite oxidation in Agrobacterium tumefaciens GW4. Sci Rep 2017; 7:43225. [PMID: 28252030 PMCID: PMC5333119 DOI: 10.1038/srep43225] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 01/23/2017] [Indexed: 11/29/2022] Open
Abstract
Antimonite [Sb(III)]-oxidizing bacteria can transform the toxic Sb(III) into the less toxic antimonate [Sb(V)]. Recently, the cytoplasmic Sb(III)-oxidase AnoA and the periplasmic arsenite [As(III)] oxidase AioAB were shown to responsible for bacterial Sb(III) oxidation, however, disruption of each gene only partially decreased Sb(III) oxidation efficiency. This study showed that in Agrobacterium tumefaciens GW4, Sb(III) induced cellular H2O2 content and H2O2 degradation gene katA. Gene knock-out/complementation of katA, anoA, aioA and anoA/aioA and Sb(III) oxidation and growth experiments showed that katA, anoA and aioA were essential for Sb(III) oxidation and resistance and katA was also essential for H2O2 resistance. Furthermore, linear correlations were observed between cellular H2O2 and Sb(V) content in vivo and chemical H2O2 and Sb(V) content in vitro (R2 = 0.93 and 0.94, respectively). These results indicate that besides the biotic factors, the cellular H2O2 induced by Sb(III) also catalyzes bacterial Sb(III) oxidation as an abiotic oxidant. The data reveal a novel mechanism that bacterial Sb(III) oxidation is associated with abiotic (cellular H2O2) and biotic (AnoA and AioAB) factors and Sb(III) oxidation process consumes cellular H2O2 which contributes to microbial detoxification of both Sb(III) and cellular H2O2.
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Affiliation(s)
- Jingxin Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Birong Yang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Manman Shi
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Kai Yuan
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Wei Guo
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Qian Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China
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Oremland RS, Stolz JF. Metabolomic changes in response to toxic arsenite. Environ Microbiol 2017; 19:413-414. [DOI: 10.1111/1462-2920.13596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | - John F. Stolz
- Department of Biological Sciences; Duquesne University; Pittsburgh PA 15282 USA
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An Oxidoreductase AioE is Responsible for Bacterial Arsenite Oxidation and Resistance. Sci Rep 2017; 7:41536. [PMID: 28128323 PMCID: PMC5270249 DOI: 10.1038/srep41536] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 12/19/2016] [Indexed: 11/08/2022] Open
Abstract
Previously, we found that arsenite (AsIII) oxidation could improve the generation of ATP/NADH to support the growth of Agrobacterium tumefaciens GW4. In this study, we found that aioE is induced by AsIII and located in the arsenic island near the AsIII oxidase genes aioBA and co-transcripted with the arsenic resistant genes arsR1-arsC1-arsC2-acr3-1. AioE belongs to TrkA family corresponding the electron transport function with the generation of NADH and H+. An aioE in-frame deletion strain showed a null AsIII oxidation and a reduced AsIII resistance, while a cytC mutant only reduced AsIII oxidation efficiency. With AsIII, aioE was directly related to the increase of NADH, while cytC was essential for ATP generation. In addition, cyclic voltammetry analysis showed that the redox potential (ORP) of AioBA and AioE were +0.297 mV vs. NHE and +0.255 mV vs. NHE, respectively. The ORP gradient is AioBA > AioE > CytC (+0.217 ~ +0.251 mV vs. NHE), which infers that electron may transfer from AioBA to CytC via AioE. The results indicate that AioE may act as a novel AsIII oxidation electron transporter associated with NADH generation. Since AsIII oxidation contributes AsIII detoxification, the essential of AioE for AsIII resistance is also reasonable.
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Microbial Antimony Biogeochemistry: Enzymes, Regulation, and Related Metabolic Pathways. Appl Environ Microbiol 2016; 82:5482-95. [PMID: 27342551 DOI: 10.1128/aem.01375-16] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antimony (Sb) is a toxic metalloid that occurs widely at trace concentrations in soil, aquatic systems, and the atmosphere. Nowadays, with the development of its new industrial applications and the corresponding expansion of antimony mining activities, the phenomenon of antimony pollution has become an increasingly serious concern. In recent years, research interest in Sb has been growing and reflects a fundamental scientific concern regarding Sb in the environment. In this review, we summarize the recent research on bacterial antimony transformations, especially those regarding antimony uptake, efflux, antimonite oxidation, and antimonate reduction. We conclude that our current understanding of antimony biochemistry and biogeochemistry is roughly equivalent to where that of arsenic was some 20 years ago. This portends the possibility of future discoveries with regard to the ability of microorganisms to conserve energy for their growth from antimony redox reactions and the isolation of new species of "antimonotrophs."
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Regulatory Activities of Four ArsR Proteins in Agrobacterium tumefaciens 5A. Appl Environ Microbiol 2016; 82:3471-3480. [PMID: 27037117 DOI: 10.1128/aem.00262-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 03/28/2016] [Indexed: 02/08/2023] Open
Abstract
UNLABELLED ArsR is a well-studied transcriptional repressor that regulates microbe-arsenic interactions. Most microorganisms have an arsR gene, but in cases where multiple copies exist, the respective roles or potential functional overlap have not been explored. We examined the repressors encoded by arsR1 and arsR2 (ars1 operon) and by arsR3 and arsR4 (ars2 operon) in Agrobacterium tumefaciens 5A. ArsR1 and ArsR4 are very similar in their primary sequences and diverge phylogenetically from ArsR2 and ArsR3, which are also quite similar to one another. Reporter constructs (lacZ) for arsR1, arsR2, and arsR4 were all inducible by As(III), but expression of arsR3 (monitored by reverse transcriptase PCR) was not influenced by As(III) and appeared to be linked transcriptionally to an upstream lysR-type gene. Experiments using a combination of deletion mutations and additional reporter assays illustrated that the encoded repressors (i) are not all autoregulatory as is typically known for ArsR proteins, (ii) exhibit variable control of each other's encoding genes, and (iii) exert variable control of other genes previously shown to be under the control of ArsR1. Furthermore, ArsR2, ArsR3, and ArsR4 appear to have an activator-like function for some genes otherwise repressed by ArsR1, which deviates from the well-studied repressor role of ArsR proteins. The differential regulatory activities suggest a complex regulatory network not previously observed in ArsR studies. The results indicate that fine-scale ArsR sequence deviations of the reiterated regulatory proteins apparently translate to different regulatory roles. IMPORTANCE Given the significance of the ArsR repressor in regulating various aspects of microbe-arsenic interactions, it is important to assess potential regulatory overlap and/or interference when a microorganism carries multiple copies of arsR This study explores this issue and shows that the four arsR genes in A. tumefaciens 5A, associated with two separate ars operons, encode proteins exhibiting various degrees of functional overlap with respect to autoregulation and cross-regulation, as well as control of other functional genes. In some cases, differences in regulatory activity are associated with only limited differences in protein primary structure. The experiments summarized herein also present evidence that ArsR proteins appear to have activator functions, representing novel regulatory activities for ArsR, previously known only to be a repressor.
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Andres J, Bertin PN. The microbial genomics of arsenic. FEMS Microbiol Rev 2016; 40:299-322. [DOI: 10.1093/femsre/fuv050] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/28/2015] [Indexed: 12/17/2022] Open
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Li J, Wang Q, Li M, Yang B, Shi M, Guo W, McDermott TR, Rensing C, Wang G. Proteomics and Genetics for Identification of a Bacterial Antimonite Oxidase in Agrobacterium tumefaciens. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:5980-5989. [PMID: 25909855 DOI: 10.1021/es506318b] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Antimony (Sb) and its compounds are listed by the United States Environmental Protection Agency (USEPA, 1979) and the European Union (CEC, 1976) as a priority pollutant. Microbial redox transformations are presumed to be an important part of antimony cycling in nature; however, regulation of these processes and the enzymology involved are unknown. In this study, comparative proteomics and reverse transcriptase-PCR analysis of Sb(III)-oxidizing bacterium Agrobacterium tumefaciens GW4 revealed an oxidoreductase (anoA) is widely distributed in microorganisms, including at least some documented to be able to oxidize Sb(III). Deletion of the anoA gene reduced Sb(III) resistance and decreased Sb(III) oxidation by ∼27%, whereas the anoA complemented strain was similar to the wild type GW4 and a GW4 anoA overexpressing strain increased Sb(III) oxidation by ∼34%. Addition of Sb(III) up-regulated anoA expression and cloning anoA to Escherichia coli demonstrated direct transferability of this activity. A His-tag purified AnoA was found to require NADP(+) as cofactor, and exhibited a K(m) for Sb(III) of 64 ± 10 μM and a V(max) of 150 ± 7 nmol min(-1) mg(-1). This study contributes important initial steps toward a mechanistic understanding of microbe-antimony interactions and enhances our understanding of how microorganisms participate in antimony biogeochemical cycling in nature.
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Affiliation(s)
- Jingxin Li
- †State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Qian Wang
- †State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Mingshun Li
- †State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Birong Yang
- †State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Manman Shi
- †State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Wei Guo
- †State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Timothy R McDermott
- ‡Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, Montana 59717, United States
| | - Christopher Rensing
- §Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, DK-1871, Denmark
| | - Gejiao Wang
- †State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China
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Abstract
Arsenic and antimony are toxic metalloids and are considered priority environmental pollutants by the U.S. Environmental Protection Agency. Significant advances have been made in understanding microbe-arsenic interactions and how they influence arsenic redox speciation in the environment. However, even the most basic features of how and why a microorganism detects and reacts to antimony remain poorly understood. Previous work with Agrobacterium tumefaciens strain 5A concluded that oxidation of antimonite [Sb(III)] and arsenite [As(III)] required different biochemical pathways. Here, we show with in vivo experiments that a mutation in aioA [encoding the large subunit of As(III) oxidase] reduces the ability to oxidize Sb(III) by approximately one-third relative to the ability of the wild type. Further, in vitro studies with the purified As(III) oxidase from Rhizobium sp. strain NT-26 (AioA shares 94% amino acid sequence identity with AioA of A. tumefaciens) provide direct evidence of Sb(III) oxidation but also show a significantly decreased Vmax compared to that of As(III) oxidation. The aioBA genes encoding As(III) oxidase are induced by As(III) but not by Sb(III), whereas arsR gene expression is induced by both As(III) and Sb(III), suggesting that detection and transcriptional responses for As(III) and Sb(III) differ. While Sb(III) and As(III) are similar with respect to cellular extrusion (ArsB or Acr3) and interaction with ArsR, they differ in the regulatory mechanisms that control the expression of genes encoding the different Ars or Aio activities. In summary, this study documents an enzymatic basis for microbial Sb(III) oxidation, although additional Sb(III) oxidation activity also is apparent in this bacterium.
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An ArsR/SmtB family member is involved in the regulation by arsenic of the arsenite oxidase operon in Thiomonas arsenitoxydans. Appl Environ Microbiol 2014; 80:6413-26. [PMID: 25107975 DOI: 10.1128/aem.01771-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genetic organization of the aioBA operon, encoding the arsenite oxidase of the moderately acidophilic and facultative chemoautotrophic bacterium Thiomonas arsenitoxydans, is different from that of the aioBA operon in the other arsenite oxidizers, in that it encodes AioF, a metalloprotein belonging to the ArsR/SmtB family. AioF is stabilized by arsenite, arsenate, or antimonite but not molybdate. Arsenic is tightly attached to AioF, likely by cysteine residues. When loaded with arsenite or arsenate, AioF is able to bind specifically to the regulatory region of the aio operon at two distinct positions. In Thiomonas arsenitoxydans, the promoters of aioX and aioB are convergent, suggesting that transcriptional interference occurs. These results indicate that the regulation of the aioBA operon is more complex in Thiomonas arsenitoxydans than in the other aioBA containing arsenite oxidizers and that the arsenic binding protein AioF is involved in this regulation. On the basis of these data, a model to explain the tight control of aioBA expression by arsenic in Thiomonas arsenitoxydans is proposed.
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