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He G, Chen G, Xie Y, Swift CM, Ramirez D, Cha G, Konstantinidis KT, Radosevich M, Löffler FE. Sustained bacterial N 2O reduction at acidic pH. Nat Commun 2024; 15:4092. [PMID: 38750010 PMCID: PMC11096178 DOI: 10.1038/s41467-024-48236-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 04/23/2024] [Indexed: 05/18/2024] Open
Abstract
Nitrous oxide (N2O) is a climate-active gas with emissions predicted to increase due to agricultural intensification. Microbial reduction of N2O to dinitrogen (N2) is the major consumption process but microbial N2O reduction under acidic conditions is considered negligible, albeit strongly acidic soils harbor nosZ genes encoding N2O reductase. Here, we study a co-culture derived from acidic tropical forest soil that reduces N2O at pH 4.5. The co-culture exhibits bimodal growth with a Serratia sp. fermenting pyruvate followed by hydrogenotrophic N2O reduction by a Desulfosporosinus sp. Integrated omics and physiological characterization revealed interspecies nutritional interactions, with the pyruvate fermenting Serratia sp. supplying amino acids as essential growth factors to the N2O-reducing Desulfosporosinus sp. Thus, we demonstrate growth-linked N2O reduction between pH 4.5 and 6, highlighting microbial N2O reduction potential in acidic soils.
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Affiliation(s)
- Guang He
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA
- Department of Civil and Environmental Engineering, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA
| | - Gao Chen
- Department of Civil and Environmental Engineering, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA
- Center for Environmental Biotechnology, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA
| | - Yongchao Xie
- Department of Civil and Environmental Engineering, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Cynthia M Swift
- Department of Civil and Environmental Engineering, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA
- Center for Environmental Biotechnology, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA
| | - Diana Ramirez
- Department of Microbiology, The University of Tennessee Knoxville, Knoxville, TN, 37996, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Gyuhyon Cha
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | | | - Mark Radosevich
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA
| | - Frank E Löffler
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA.
- Department of Civil and Environmental Engineering, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA.
- Center for Environmental Biotechnology, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA.
- Department of Microbiology, The University of Tennessee Knoxville, Knoxville, TN, 37996, USA.
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
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2
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Cimmino L, Duarte AG, Ni D, Ekundayo BE, Pereira IAC, Stahlberg H, Holliger C, Maillard J. Structure of a membrane-bound menaquinol:organohalide oxidoreductase. Nat Commun 2023; 14:7038. [PMID: 37923808 PMCID: PMC10624902 DOI: 10.1038/s41467-023-42927-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 10/26/2023] [Indexed: 11/06/2023] Open
Abstract
Organohalide-respiring bacteria are key organisms for the bioremediation of soils and aquifers contaminated with halogenated organic compounds. The major players in this process are respiratory reductive dehalogenases, corrinoid enzymes that use organohalides as substrates and contribute to energy conservation. Here, we present the structure of a menaquinol:organohalide oxidoreductase obtained by cryo-EM. The membrane-bound protein was isolated from Desulfitobacterium hafniense strain TCE1 as a PceA2B2 complex catalysing the dechlorination of tetrachloroethene. Two catalytic PceA subunits are anchored to the membrane by two small integral membrane PceB subunits. The structure reveals two menaquinone molecules bound at the interface of the two different subunits, which are the starting point of a chain of redox cofactors for electron transfer to the active site. In this work, the structure elucidates how energy is conserved during organohalide respiration in menaquinone-dependent organohalide-respiring bacteria.
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Affiliation(s)
- Lorenzo Cimmino
- Laboratory for Environmental Biotechnology, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Américo G Duarte
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Dongchun Ni
- Laboratory of Biological Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), and Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Babatunde E Ekundayo
- Laboratory of Biological Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), and Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Inês A C Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Henning Stahlberg
- Laboratory of Biological Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), and Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland.
| | - Christof Holliger
- Laboratory for Environmental Biotechnology, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Julien Maillard
- Laboratory for Environmental Biotechnology, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
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3
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Xie Y, Erşan S, Guan X, Wang J, Sha J, Xu S, Wohlschlegel JA, Park JO, Liu C. Unexpected metabolic rewiring of CO 2 fixation in H 2-mediated materials-biology hybrids. Proc Natl Acad Sci U S A 2023; 120:e2308373120. [PMID: 37816063 PMCID: PMC10589654 DOI: 10.1073/pnas.2308373120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 08/31/2023] [Indexed: 10/12/2023] Open
Abstract
A hybrid approach combining water-splitting electrochemistry and H2-oxidizing, CO2-fixing microorganisms offers a viable solution for producing value-added chemicals from sunlight, water, and air. The classic wisdom without thorough examination to date assumes that the electrochemistry in such a H2-mediated process is innocent of altering microbial behavior. Here, we report unexpected metabolic rewiring induced by water-splitting electrochemistry in H2-oxidizing acetogenic bacterium Sporomusa ovata that challenges such a classic view. We found that the planktonic S. ovata is more efficient in utilizing reducing equivalent for ATP generation in the materials-biology hybrids than cells grown with H2 supply, supported by our metabolomic and proteomic studies. The efficiency of utilizing reducing equivalents and fixing CO2 into acetate has increased from less than 80% of chemoautotrophy to more than 95% under electroautotrophic conditions. These observations unravel previously underappreciated materials' impact on microbial metabolism in seemingly simply H2-mediated charge transfer between biotic and abiotic components. Such a deeper understanding of the materials-biology interface will foster advanced design of hybrid systems for sustainable chemical transformation.
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Affiliation(s)
- Yongchao Xie
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | - Sevcan Erşan
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA90095
| | - Xun Guan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | - Jingyu Wang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | - Jihui Sha
- Department of Biological Chemistry, University of California, Los Angeles, CA90095
| | - Shuangning Xu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | | | - Junyoung O. Park
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA90095
- California NanoSystems Institute, University of California, Los Angeles, CA90095
| | - Chong Liu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
- California NanoSystems Institute, University of California, Los Angeles, CA90095
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4
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Shen R, Zhang S, Liang Z, Mai B, Wang S. Mechanistic insight into co-metabolic dechlorination of hexachloro-1,3-butadiene in Dehalococcoides. WATER RESEARCH 2022; 220:118725. [PMID: 35709597 DOI: 10.1016/j.watres.2022.118725] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 05/06/2022] [Accepted: 06/06/2022] [Indexed: 06/15/2023]
Abstract
Hexachloro-1,3-butadiene (HCBD) as one of emerging persistent organic pollutants (POPs) poses potential risk to human health and ecosystems. Organohalide-respiring bacteria (OHRB)-mediated reductive dehalogenation represents a promising strategy to remediate HCBD-contaminated sites. Nonetheless, information on the HCBD-dechlorinating OHRB and their dechlorination pathways remain unknown. In this study, both in vivo and in vitro experiments, as well as quantum chemical calculation, were employed to successfully identify and characterize the reductive dechlorination of HCBD by Dehalococcoides. Results showed that some Dehalococcoides extensively dechlorinated HCBD to (E)-1,2,3-tri-CBD via (E)-1,1,2,3,4-penta-CBD and (Z,E)-1,2,3,4-tetra-CBD in a co-metabolic way. Both qPCR and 16S rRNA gene amplicon sequencing analyses suggested that the HCBD-dechlorinating Dehalococcoides coupled their cell growth with dechlorination of perchloroethene (PCE), rather than HCBD. The in vivo and in vitro ATPase assays indicated ≥78.89% decrease in ATPase activity upon HCBD addition, which suggested HCBD inhibition on ATPase-mediated energy harvest and provided rationality on the Dehalococcoides-mediated co-metabolic dechlorination of HCBD. Interestingly, dehalogenation screening of organohalides with the HCBD-dechlorinating enrichment cultures showed that debromination of bromodichloromethane (BDCM) was active in the in vitro RDase assays but non-active in the in vivo experiments. Further in vitro assays of hydrogenase activity suggested that significant inhibition of BDCM on the hydrogenase activity could block electron derivation from H2 for consequent reduction of organohalides in the in vivo experiments. Therefore, our results provided unprecedented insight into metabolic, co-metabolic and RDase-active-only dehalogenation of varied organohalides by specific OHRB, which could guide future screening of OHRB for remediation of sites contaminated by HCBD and other POPs.
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Affiliation(s)
- Rui Shen
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou, 510006 China
| | - Shangwei Zhang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou, 510006 China
| | - Zhiwei Liang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou, 510006 China
| | - Bixian Mai
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640 China
| | - Shanquan Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou, 510006 China.
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5
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Hudari MSB, Richnow H, Vogt C, Nijenhuis I. Mini-review: effect of temperature on microbial reductive dehalogenation of chlorinated ethenes: a review. FEMS Microbiol Ecol 2022; 98:6638985. [PMID: 35810002 DOI: 10.1093/femsec/fiac081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 06/30/2022] [Accepted: 07/07/2022] [Indexed: 11/13/2022] Open
Abstract
Temperature is a key factor affecting microbial activity and ecology. An increase in temperature generally increases rates of microbial processes up to a certain threshold, above which rates decline rapidly. In the subsurface, temperature of groundwater is usually stable and related to the annual average temperature at the surface. However, anthropogenic activities related to the use of the subsurface, e.g. for thermal heat management, foremost heat storage, will affect the temperature of groundwater locally. This mini-review intends to summarize the current knowledge on reductive dehalogenation activities of the chlorinated ethenes, common urban groundwater contaminants, at different temperatures. This includes an overview of activity and dehalogenation extent at different temperatures in laboratory isolates and enrichment cultures, the effect of shifts in temperature in micro- and mesocosm studies as well as observed biotransformation at different natural and induced temperatures at contaminated field sites. Furthermore, we address indirect effects on biotransformation, e.g. changes in fermentation, methanogenesis and sulfate reduction as competing or synergetic microbial processes. Finally, we address the current gaps in knowledge regarding bioremediation of chlorinated ethenes, microbial community shifts and bottlenecks for active combination with thermal energy storage, and necessities for bioaugmentation and/or natural re-populations after exposure to high temperature.
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Affiliation(s)
- Mohammad Sufian Bin Hudari
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Hans Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Carsten Vogt
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Ivonne Nijenhuis
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
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6
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Lu CW, Kao CM, Le NN, Lin CC, Chen SC. Long-term dechlorination of cis-DCE to ethene with co-immobilized Dehalococcoides mccartyi BAV1 and Clostridium butyricum in silica gel system. JOURNAL OF HAZARDOUS MATERIALS 2022; 430:128355. [PMID: 35149497 DOI: 10.1016/j.jhazmat.2022.128355] [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: 10/03/2021] [Revised: 12/20/2021] [Accepted: 01/23/2022] [Indexed: 06/14/2023]
Abstract
Chloroethenes are common groundwater pollutants, and have been classified as toxic and carcinogenic to humans. The metabolites of chloroethenes, cis-dichloroethene (cis-DCE) and vinyl chloride (VC) commonly accumulate in groundwater due to their recalcitrant reductive dechlorination under anaerobic conditions. Dehalococcoides mccartyi (Dhc) is the key anaerobic bacteria for complete dechlorination of chloroethene, and Clostridium butyricum (C. butyricum) can provide hydrogen for supporting the growth of Dhc. In this study, we co-immobilized Dhc strain BAV1 and C. butyricum in a silica gel to determine the ability of the complete dechlorination of cis-DCE. Our results showed that our immobilized system could protect BAV1 from a high concentration (8 mM) of cis-DCE to carry out complete dechlorination. After the long-term use of our immobilized system, the activity of complete dechlorination was maintained for more than 180 consecutive days. Furthermore, we applied the immobilized system to remediate contaminated groundwater and uncovered the complete dechlorination of cis-DCE into ethene, a non-toxic product, within 28 days. Therefore, this novel co-immobilized system could serve a solution for bioremediation at chloroethene-contaminated sites.
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Affiliation(s)
- Che-Wei Lu
- Department of Life Sciences, National Central University, Taoyuan 32001, Taiwan
| | - Chih-Ming Kao
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
| | - Nhu Nguyet Le
- Department of Life Sciences, National Central University, Taoyuan 32001, Taiwan
| | - Chu-Ching Lin
- Institute of Environmental Engineering, National Central University, Taoyuan 32001, Taiwan
| | - Ssu-Ching Chen
- Department of Life Sciences, National Central University, Taoyuan 32001, Taiwan.
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7
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Ha BN, Pham DM, Kasai T, Awata T, Katayama A. Effect of Humin and Chemical Factors on CO 2-Fixing Acetogenesis and Methanogenesis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19052546. [PMID: 35270239 PMCID: PMC8909181 DOI: 10.3390/ijerph19052546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 02/04/2023]
Abstract
Acetogenesis and methanogenesis have attracted attention as CO2-fixing reactions. Humin, a humic substance insoluble at any pH, has been found to assist CO2-fixing acetogenesis as the sole electron donor. Here, using two CO2-fixing consortia with acetogenic and methanogenic activities, the effect of various parameters on these activities was examined. One consortium utilized humin and hydrogen (H2) as electron donors for acetogenesis, either separately or simultaneously, but with a preference for the electron use from humin. The acetogenic activity was accelerated 14 times by FeS at 0.2 g/L as the optimal concentration, while being inhibited by MgSO4 at concentration above 0.02 g/L and by NaCl at concentrations higher than 6 g/L. Another consortium did not utilize humin but H2 as electron donor, suggesting that humin was not a universal electron donor for acetogenesis. For methanogenesis, both consortia did not utilize extracellular electrons from humin unless H2 was present. The methanogenesis was promoted by FeS at 0.2 g/L or higher concentrations, especially without humin, and with NaCl at 2 g/L or higher concentrations regardless of the presence of humin, while no significant effect was observed with MgSO4. Comparative sequence analysis of partial 16S rRNA genes suggested that minor groups were the humin-utilizing acetogens in the consortium dominated by Clostridia, while Methanobacterium was the methanogen utilizing humin with H2.
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Affiliation(s)
- Biec Nhu Ha
- Department of Civil Engineering, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan; (B.N.H.); (T.K.)
| | - Duyen Minh Pham
- Institute of Materials and Systems for Sustainability, Nagoya University, Chikusa, Nagoya 464-8603, Japan;
| | - Takuya Kasai
- Department of Civil Engineering, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan; (B.N.H.); (T.K.)
- Institute of Materials and Systems for Sustainability, Nagoya University, Chikusa, Nagoya 464-8603, Japan;
| | - Takanori Awata
- Graduate School of Engineering, Osaka Institute of Technology, Osaka 535-8585, Japan;
| | - Arata Katayama
- Department of Civil Engineering, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan; (B.N.H.); (T.K.)
- Institute of Materials and Systems for Sustainability, Nagoya University, Chikusa, Nagoya 464-8603, Japan;
- Correspondence: ; Tel.: +81-52-789-5856
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8
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Wu B, Liu F, Fang W, Yang T, Chen GH, He Z, Wang S. Microbial sulfur metabolism and environmental implications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 778:146085. [PMID: 33714092 DOI: 10.1016/j.scitotenv.2021.146085] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/19/2021] [Accepted: 02/20/2021] [Indexed: 06/12/2023]
Abstract
Sulfur as a macroelement plays an important role in biochemistry in both natural environments and engineering biosystems, which can be further linked to other important element cycles, e.g. carbon, nitrogen and iron. Consequently, the sulfur cycling primarily mediated by sulfur compounds oxidizing microorganisms and sulfur compounds reducing microorganisms has enormous environmental implications, particularly in wastewater treatment and pollution bioremediation. In this review, to connect the knowledge in microbial sulfur metabolism to environmental applications, we first comprehensively review recent advances in understanding microbial sulfur metabolisms at molecular-, cellular- and ecosystem-levels, together with their energetics. We then discuss the environmental implications to fight against soil and water pollution, with four foci: (1) acid mine drainage, (2) water blackening and odorization in urban rivers, (3) SANI® and DS-EBPR processes for sewage treatment, and (4) bioremediation of persistent organic pollutants. In addition, major challenges and further developments toward elucidation of microbial sulfur metabolisms and their environmental applications are identified and discussed.
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Affiliation(s)
- Bo Wu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| | - Feifei Liu
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, State Key Laboratory of Applied Microbiology Southern China, Guangzhou 510070, China
| | - Wenwen Fang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| | - Tony Yang
- Swift Current Research and Development Centre, Agriculture and Agri-Food Canada, Swift Current, SK S9H 3X2, Canada
| | - Guang-Hao Chen
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Zhili He
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| | - Shanquan Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China.
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9
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Low A, Zhao S, Rogers MJ, Zemb O, Lee M, He J, Manefield M. Isolation, characterization and bioaugmentation of an acidotolerant 1,2-dichloroethane respiring Desulfitobacterium species from a low pH aquifer. FEMS Microbiol Ecol 2020; 95:5454739. [PMID: 30980656 DOI: 10.1093/femsec/fiz055] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Accepted: 04/11/2019] [Indexed: 01/14/2023] Open
Abstract
A Desulfitobacterium sp. strain AusDCA of the Peptococcaceae family capable of respiring 1,2-dichloroethane (1,2-DCA) to ethene anaerobically with ethanol or hydrogen as electron donor at pH 5.0 with optimal range between pH 6.5-7.5 was isolated from an acidic aquifer near Sydney, Australia. Strain AusDCA is distant (94% nucleotide identity) from its nearest phylogenetic neighbor, D. metallireducens, and could represent a new species. Reference gene-based quantification of growth indicated a doubling time of 2 days in cultures buffered at pH 7.2, and a yield of 7.66 (± 4.0) × 106 cells µmol-1 of 1,2-DCA. A putative 1,2-DCA reductive dehalogenase was translated from a dcaAB locus and had high amino acid identity (97.3% for DcaA and 100% for DcaB) to RdhA1B1 of the 1,2-DCA respiring Dehalobacter strain WL. Proteomic analysis confirmed DcaA expression in the pure culture. Dehalogenation of 1,2-DCA (1.6 mM) was observed in batch cultures established from groundwater at pH 5.5 collected 38 days after in situ bioaugmentation but not in cultures established with groundwater collected at the same time from wells not receiving bioaugmentation. Overall, strain AusDCA can tolerate lower pH than previously characterized organohalide respiring bacteria and remained viable in groundwater at pH 5.5.
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Affiliation(s)
- Adrian Low
- Genome Structural Biology, Temasek Lifesciences Laboratory, 1 Research Link, Singapore 117604, Singapore
| | - Siyan Zhao
- Department of Civil and Environmental Engineering, National University of Singapore, Block E2-02-13, 1 Engineering Drive 3, Singapore 117576, Singapore
| | - Matthew J Rogers
- Department of Civil and Environmental Engineering, National University of Singapore, Block E2-02-13, 1 Engineering Drive 3, Singapore 117576, Singapore
| | - Olivier Zemb
- GenPhySE, Université de Toulouse, INRA, INPT, ENVT, Castanet Tolosan, France
| | - Matthew Lee
- School of Civil and Environmental Engineering, Water Research Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | - Jianzhong He
- Department of Civil and Environmental Engineering, National University of Singapore, Block E2-02-13, 1 Engineering Drive 3, Singapore 117576, Singapore
| | - Mike Manefield
- School of Chemical Engineering, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia
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10
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Liang X, Radosevich M, Löffler F, Schaeffer SM, Zhuang J. Impact of microbial iron oxide reduction on the transport of diffusible tracers and non-diffusible nanoparticles in soils. CHEMOSPHERE 2019; 220:391-402. [PMID: 30597359 DOI: 10.1016/j.chemosphere.2018.12.165] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 11/22/2018] [Accepted: 12/22/2018] [Indexed: 06/09/2023]
Abstract
In subsurface bioremediation, electron donor addition promotes microbial Fe(III)-oxide mineral reduction that could change soil pore structure, release colloids, and alter soil surface properties. These processes in turn may impact bioremediation rates and the ultimate fate of contaminants. Columns packed with water-stable, Fe-oxide-rich soil aggregates were infused with acetate-containing artificial groundwater and operated for 20 d or 60 d inside an anoxic chamber. Soluble Fe(II) and soil colloids were detected in the effluent within one week after initiation of the acetate addition, demonstrating Fe(III)-bioreduction and colloid formation. Diffusible Br-, less diffusible 2,6-difluorobenzoate (DFBA), and non-diffusible silica-shelled silver nanoparticles (SSSNP) were used as tracers in transport experiments before and after the bioreduction. The transport of Br- was not influenced by the bioreduction. DFBA showed earlier breakthrough and less tailing after the bioreduction, suggesting alterations in flow paths and soil surface chemistry during the 20-d bioreduction treatment. Similarly, the bioreduction increased the transport of SSSNP very significantly, with mass recovery increasing from 1.7% to 25.1%. Unexpectedly, the SSSNP was completely retained in the columns when the acetate injection was extended from 20 to 60 d, while the mass recovery of DFBA decreased from 89.1% to 84.1% and Br- showed no change. The large change in the transport of SSSNP was attributed to soil aggregate breakdown and colloid release (causing mechanical straining of SSSNP) and the exposure of iron oxide surfaces previously unavailable within aggregate interiors (facilitating attachment of SSSNP). These results suggest a time-dependent fashion of microbial effect on the transport of diffusivity-varying tracers.
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Affiliation(s)
- Xiaolong Liang
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, TN 37996, USA
| | - Mark Radosevich
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, TN 37996, USA
| | - Frank Löffler
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, TN 37996, USA; Department of Microbiology, Department of Civil and Environmental Engineering, Center for Environmental Biotechnology, The University of Tennessee, Knoxville, TN 37996, USA; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Sean M Schaeffer
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, TN 37996, USA
| | - Jie Zhuang
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, TN 37996, USA.
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11
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Proteogenomics Reveals Novel Reductive Dehalogenases and Methyltransferases Expressed during Anaerobic Dichloromethane Metabolism. Appl Environ Microbiol 2019; 85:AEM.02768-18. [PMID: 30658979 DOI: 10.1128/aem.02768-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Accepted: 01/08/2019] [Indexed: 11/20/2022] Open
Abstract
Dichloromethane (DCM) is susceptible to microbial degradation under anoxic conditions and is metabolized via the Wood-Ljungdahl pathway; however, mechanistic understanding of carbon-chlorine bond cleavage is lacking. The microbial consortium RM contains the DCM degrader "Candidatus Dichloromethanomonas elyunquensis" strain RM, which strictly requires DCM as a growth substrate. Proteomic workflows applied to DCM-grown consortium RM biomass revealed a total of 1,705 nonredundant proteins, 521 of which could be assigned to strain RM. In the presence of DCM, strain RM expressed a complete set of Wood-Ljungdahl pathway enzymes, as well as proteins implicated in chemotaxis, motility, sporulation, and vitamin/cofactor synthesis. Four corrinoid-dependent methyltransferases were among the most abundant proteins. Notably, two of three putative reductive dehalogenases (RDases) encoded within strain RM's genome were also detected in high abundance. Expressed RDase 1 and RDase 2 shared 30% amino acid identity, and RDase 1 was most similar to an RDase of Dehalococcoides mccartyi strain WBC-2 (AOV99960, 52% amino acid identity), while RDase 2 was most similar to an RDase of Dehalobacter sp. strain UNSWDHB (EQB22800, 72% amino acid identity). Although the involvement of RDases in anaerobic DCM metabolism has yet to be experimentally verified, the proteome characterization results implicated the possible participation of one or more reductive dechlorination steps and methyl group transfer reactions, leading to a revised proposal for an anaerobic DCM degradation pathway.IMPORTANCE Naturally produced and anthropogenically released DCM can reside in anoxic environments, yet little is known about the diversity of organisms, enzymes, and mechanisms involved in carbon-chlorine bond cleavage in the absence of oxygen. A proteogenomic approach identified two RDases and four corrinoid-dependent methyltransferases expressed by the DCM degrader "Candidatus Dichloromethanomonas elyunquensis" strain RM, suggesting that reductive dechlorination and methyl group transfer play roles in anaerobic DCM degradation. These findings suggest that the characterized DCM-degrading bacterium Dehalobacterium formicoaceticum and "Candidatus Dichloromethanomonas elyunquensis" strain RM utilize distinct strategies for carbon-chlorine bond cleavage, indicating that multiple pathways evolved for anaerobic DCM metabolism. The specific proteins (e.g., RDases and methyltransferases) identified in strain RM may have value as biomarkers for monitoring anaerobic DCM degradation in natural and contaminated environments.
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Collins FA, Fisher K, Payne KAP, Gaytan Mondragon S, Rigby SEJ, Leys D. NADPH-Driven Organohalide Reduction by a Nonrespiratory Reductive Dehalogenase. Biochemistry 2018; 57:3493-3502. [PMID: 29630828 DOI: 10.1021/acs.biochem.8b00255] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Reductive dehalogenases are corrinoid and iron-sulfur cluster-dependent enzymes that mostly act as the terminal oxidoreductases in the bacterial organohalide respiration process. This process often leads to detoxification of recalcitrant organohalide pollutants. While low cell yields and oxygen sensitivity hamper the study of many reductive dehalogenases, this is not the case for the nonrespiratory reductive dehalogenase NpRdhA from Nitratireductor pacificus. We here report in vitro and in vivo reconstitution of an NADPH-dependent reducing system for NpRdhA. Surprisingly, NpRdhA mediated organohalide reduction could not be supported using N. pacificus ferredoxin-NAD(P)H oxidoreductase and associated ferredoxins. Instead, we found a nonphysiological system comprised of the Escherichia coli flavodoxin reductase (EcFldr) in combination with spinach ferredoxin (SpFd) was able to support NADPH-dependent organohalide reduction by NpRdhA. Using this system, organohalide reduction can be performed under both anaerobic and aerobic conditions, with 1.1 ± 0.1 and 3.5 ± 0.3 equiv of NADPH consumed per product produced, respectively. No significant enzyme inactivation under aerobic conditions was observed, suggesting a Co(I) species is unlikely to be present under steady state conditions. Furthermore, reduction of the Co(II) resting state was not observed in the absence of substrate. Only the coexpression of EcFldr, SpFd, and NpRdhA in Bacillus megaterium conferred the latter with the ability to reduce brominated NpRdhA substrates in vivo, in agreement with our in vitro observations. Our work provides new insights into biological reductive dehalogenase reduction and establishes a blueprint for the minimal functional organohalide reduction module required for bioremediation in situ.
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Affiliation(s)
- Fraser A Collins
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| | - Karl Fisher
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| | - Karl A P Payne
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| | - Samantha Gaytan Mondragon
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| | - Stephen E J Rigby
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| | - David Leys
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
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13
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El-Sayed WS. Characterization of a Highly Enriched Microbial Consortium Reductively Dechlorinating 2,3-Dichlorophenol and 2,4,6-Trichlorophenol and the Corresponding cprA Genes from River Sediment. Pol J Microbiol 2018; 65:341-352. [PMID: 29334051 DOI: 10.5604/17331331.1215613] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Anaerobic reductive dechlorination of 2,3-dichlorophenol (2,3DCP) and 2,4,6-trichlorophenol (2,4,6TCP) was investigated in microcosms from River Nile sediment. A stable sediment-free anaerobic microbial consortium reductively dechlorinating 2,3DCP and 2,4,6TCP was established. Defined sediment-free cultures showing stable dechlorination were restricted to ortho chlorine when enriched with hydrogen as the electron donor, acetate as the carbon source, and either 2,3-DCP or 2,4,6-TCP as electron acceptors. When acetate, formate, or pyruvate were used as electron donors, dechlorination activity was lost. Only lactate can replace dihydrogen as an electron donor. However, the dechlorination potential was decreased after successive transfers. To reveal chlororespiring species, the microbial community structure of chlorophenol-reductive dechlorinating enrichment cultures was analyzed by PCR-denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments. Eight dominant bacteria were detected in the dechlorinating microcosms including members of the genera Citrobacter, Geobacter, Pseudomonas, Desulfitobacterium, Desulfovibrio and Clostridium. Highly enriched dechlorinating cultures were dominated by four bacterial species belonging to the genera Pseudomonas, Desulfitobacterium, and Clostridium. Desulfitobacterium represented the major fraction in DGGE profiles indicating its importance in dechlorination activity, which was further confirmed by its absence resulting in complete loss of dechlorination. Reductive dechlorination was confirmed by the stoichiometric dechlorination of 2,3DCP and 2,4,6TCP to metabolites with less chloride groups and by the detection of chlorophenol RD cprA gene fragments in dechlorinating cultures. PCR amplified cprA gene fragments were cloned and sequenced and found to cluster with the cprA/pceA type genes of Dehalobacter restrictus.
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Affiliation(s)
- Wael S El-Sayed
- Biology Department, Faculty of Science, Taibah University, Almadinah Almunawarah, KSA; Microbiology Department, Faculty of Science, Ain Shams University, Cairo, Egypt
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Ang TF, Maiangwa J, Salleh AB, Normi YM, Leow TC. Dehalogenases: From Improved Performance to Potential Microbial Dehalogenation Applications. Molecules 2018; 23:E1100. [PMID: 29735886 PMCID: PMC6100074 DOI: 10.3390/molecules23051100] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/07/2018] [Accepted: 04/09/2018] [Indexed: 11/16/2022] Open
Abstract
The variety of halogenated substances and their derivatives widely used as pesticides, herbicides and other industrial products is of great concern due to the hazardous nature of these compounds owing to their toxicity, and persistent environmental pollution. Therefore, from the viewpoint of environmental technology, the need for environmentally relevant enzymes involved in biodegradation of these pollutants has received a great boost. One result of this great deal of attention has been the identification of environmentally relevant bacteria that produce hydrolytic dehalogenases—key enzymes which are considered cost-effective and eco-friendly in the removal and detoxification of these pollutants. These group of enzymes catalyzing the cleavage of the carbon-halogen bond of organohalogen compounds have potential applications in the chemical industry and bioremediation. The dehalogenases make use of fundamentally different strategies with a common mechanism to cleave carbon-halogen bonds whereby, an active-site carboxylate group attacks the substrate C atom bound to the halogen atom to form an ester intermediate and a halide ion with subsequent hydrolysis of the intermediate. Structurally, these dehalogenases have been characterized and shown to use substitution mechanisms that proceed via a covalent aspartyl intermediate. More so, the widest dehalogenation spectrum of electron acceptors tested with bacterial strains which could dehalogenate recalcitrant organohalides has further proven the versatility of bacterial dehalogenators to be considered when determining the fate of halogenated organics at contaminated sites. In this review, the general features of most widely studied bacterial dehalogenases, their structural properties, basis of the degradation of organohalides and their derivatives and how they have been improved for various applications is discussed.
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Affiliation(s)
- Thiau-Fu Ang
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - Jonathan Maiangwa
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - Abu Bakar Salleh
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Institute of Bioscience, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - Yahaya M Normi
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - Thean Chor Leow
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Institute of Bioscience, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
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15
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Suzuki K, Kato Y, Yui A, Yamamoto S, Ando S, Rubaba O, Tashiro Y, Futamata H. Bacterial communities adapted to higher external resistance can reduce the onset potential of anode in microbial fuel cells. J Biosci Bioeng 2018; 125:565-571. [DOI: 10.1016/j.jbiosc.2017.12.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 11/25/2017] [Accepted: 12/20/2017] [Indexed: 11/16/2022]
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16
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Denitrification by Anaeromyxobacter dehalogenans, a Common Soil Bacterium Lacking the Nitrite Reductase Genes nirS and nirK. Appl Environ Microbiol 2018; 84:AEM.01985-17. [PMID: 29196287 DOI: 10.1128/aem.01985-17] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 11/27/2017] [Indexed: 11/20/2022] Open
Abstract
The versatile soil bacterium Anaeromyxobacter dehalogenans lacks the hallmark denitrification genes nirS and nirK (encoding NO2 -→NO reductases) and couples growth to NO3 - reduction to NH4 + (respiratory ammonification) and to N2O reduction to N2 A. dehalogenans also grows by reducing Fe(III) to Fe(II), which chemically reacts with NO2 - to form N2O (i.e., chemodenitrification). Following the addition of 100 μmol of NO3 - or NO2 - to Fe(III)-grown axenic cultures of A. dehalogenans, 54 (±7) μmol and 113 (±2) μmol N2O-N, respectively, were produced and subsequently consumed. The conversion of NO3 - to N2 in the presence of Fe(II) through linked biotic-abiotic reactions represents an unrecognized ecophysiology of A. dehalogenans The new findings demonstrate that the assessment of gene content alone is insufficient to predict microbial denitrification potential and N loss (i.e., the formation of gaseous N products). A survey of complete bacterial genomes in the NCBI Reference Sequence database coupled with available physiological information revealed that organisms lacking nirS or nirK but with Fe(III) reduction potential and genes for NO3 - and N2O reduction are not rare, indicating that NO3 - reduction to N2 through linked biotic-abiotic reactions is not limited to A. dehalogenans Considering the ubiquity of iron in soils and sediments and the broad distribution of dissimilatory Fe(III) and NO3 - reducers, denitrification independent of NO-forming NO2 - reductases (through combined biotic-abiotic reactions) may have substantial contributions to N loss and N2O flux.IMPORTANCE Current attempts to gauge N loss from soils rely on the quantitative measurement of nirK and nirS genes and/or transcripts. In the presence of iron, the common soil bacterium Anaeromyxobacter dehalogenans is capable of denitrification and the production of N2 without the key denitrification genes nirK and nirS Such chemodenitrifiers denitrify through combined biotic and abiotic reactions and have potentially large contributions to N loss to the atmosphere and fill a heretofore unrecognized ecological niche in soil ecosystems. The findings emphasize that the comprehensive understanding of N flux and the accurate assessment of denitrification potential can be achieved only when integrated studies of interlinked biogeochemical cycles are performed.
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17
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Chen G, Kleindienst S, Griffiths DR, Mack EE, Seger ES, Löffler FE. Mutualistic interaction between dichloromethane- and chloromethane-degrading bacteria in an anaerobic mixed culture. Environ Microbiol 2017; 19:4784-4796. [DOI: 10.1111/1462-2920.13945] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 09/19/2017] [Accepted: 09/22/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Gao Chen
- Center for Environmental Biotechnology; University of Tennessee; Knoxville TN 37996 USA
- Department of Civil and Environmental Engineering; University of Tennessee; Knoxville TN 37996 USA
| | - Sara Kleindienst
- Center for Environmental Biotechnology; University of Tennessee; Knoxville TN 37996 USA
- Oak Ridge National Laboratory; University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division; Oak Ridge TN 37831 USA
- Center for Applied Geosciences; Department of Geosciences, Eberhard Karls University Tübingen; Tübingen 72074 Germany
| | | | - E. Erin Mack
- Corporate Remediation Group; E. I. DuPont de Nemours and Company; Wilmington DE 19805 USA
| | | | - Frank E. Löffler
- Center for Environmental Biotechnology; University of Tennessee; Knoxville TN 37996 USA
- Department of Civil and Environmental Engineering; University of Tennessee; Knoxville TN 37996 USA
- Oak Ridge National Laboratory; University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division; Oak Ridge TN 37831 USA
- Department of Microbiology; University of Tennessee; Knoxville TN 37996 USA
- Department of Biosystems Engineering and Soil Science; University of Tennessee; Knoxville TN 37996 USA
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18
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Chen G, Murdoch RW, Mack EE, Seger ES, Löffler FE. Complete Genome Sequence of Dehalobacterium formicoaceticum Strain DMC, a Strictly Anaerobic Dichloromethane-Degrading Bacterium. GENOME ANNOUNCEMENTS 2017; 5:e00897-17. [PMID: 28912314 PMCID: PMC5597755 DOI: 10.1128/genomea.00897-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 07/26/2017] [Indexed: 01/17/2023]
Abstract
Dehalobacterium formicoaceticum utilizes dichloromethane as the sole energy source in defined anoxic bicarbonate-buffered mineral salt medium. The products are formate, acetate, inorganic chloride, and biomass. The bacterium's genome was sequenced using PacBio, assembled, and annotated. The complete genome consists of one 3.77-Mb circular chromosome harboring 3,935 predicted protein-encoding genes.
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Affiliation(s)
- Gao Chen
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA
| | - Robert W Murdoch
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
| | - E Erin Mack
- Corporate Remediation Group, E. I. DuPont de Nemours and Company, Newark, Delaware, USA
| | | | - Frank E Löffler
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, Tennessee, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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19
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Şimşir B, Yan J, Im J, Graves D, Löffler FE. Natural Attenuation in Streambed Sediment Receiving Chlorinated Solvents from Underlying Fracture Networks. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:4821-4830. [PMID: 28328216 PMCID: PMC6944067 DOI: 10.1021/acs.est.6b05554] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Contaminant discharge from fractured bedrock formations remains a remediation challenge. We applied an integrated approach to assess the natural attenuation potential of sediment that forms the transition zone between upwelling groundwater from a chlorinated solvent-contaminated fractured bedrock aquifer and the receiving surface water. In situ measurements demonstrated that reductive dechlorination in the sediment attenuated chlorinated compounds before reaching the water column. Microcosms established with creek sediment or in situ incubated Bio-Sep beads degraded C1-C3 chlorinated solvents to less-chlorinated or innocuous products. Quantitative PCR and 16S rRNA gene amplicon sequencing revealed the abundance and spatial distribution of known dechlorinator biomarker genes within the creek sediment and demonstrated that multiple dechlorinator populations degrading chlorinated C1-C3 alkanes and alkenes co-inhabit the sediment. Phylogenetic classification of bacterial and archaeal sequences indicated a relatively uniform distribution over spatial (300 m horizontally) scale, but Dehalococcoides and Dehalobacter were more abundant in deeper sediment, where 5.7 ± 0.4 × 105 and 5.4 ± 0.9 × 106 16S rRNA gene copies per g of sediment, respectively, were measured. The microbiological and hydrogeological characterization demonstrated that microbial processes at the fractured bedrock-sediment interface were crucial for preventing contaminants reaching the water column, emphasizing the relevance of this critical zone environment for contaminant attenuation.
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Affiliation(s)
- Burcu Şimşir
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jun Yan
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China
| | - Jeongdae Im
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts 01002, United States
| | - Duane Graves
- Geosyntec Consultants, Knoxville, Tennessee 37922, United States
| | - Frank E. Löffler
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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20
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Dehalococcoides and general bacterial ecology of differentially trichloroethene dechlorinating flow-through columns. Appl Microbiol Biotechnol 2017; 101:4799-4813. [PMID: 28213734 DOI: 10.1007/s00253-017-8180-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/03/2017] [Indexed: 10/20/2022]
Abstract
The diversity of Dehalococcoides mccartyi (Dhc) and/or other organohalide respiring or associated microorganisms in parallel, partial, or complete trichloroethene (TCE) dehalogenating systems has not been well described. The composition of Dhc populations and the associated bacterial community that developed over 7.5 years in the top layer (0-10 cm) of eight TCE-fed columns were examined using pyrosequencing. Columns biostimulated with one of three carbon sources, along with non-stimulated controls, developed into complete (ethene production, whey amended), partial (cis-dichloroethene (DCE) and VC, an emulsified oil with nonionic surfactant), limited (<5 % cis-DCE and 95 % TCE, an emulsified oil), and non- (controls) TCE dehalogenating systems. Bioaugmentation of one column of each treatment with Bachman Road enrichment culture did not change Dhc populations nor the eventual degree of TCE dehalogenation. Pyrosequencing revealed high diversity among Dhc strains. There were 13 OTUs that were represented by more than 1000 sequences each. Cornell group-related populations dominated in complete TCE dehalogenating columns, while Pinellas group related Dhc dominated in all other treatments. General microbial communities varied with biostimulation, and three distinct microbial communities were established: one each for whey, oils, and control treatments. Bacterial genera, including Dehalobacter, Desulfitobacterium, Sulfurospirillum, Desulfuromonas, and Geobacter, all capable of partial TCE dehalogenation, were abundant in the limited and partial TCE dehalogenating systems. Dhc strain diversity was wider than previously reported and their composition within the community varied significantly depending on the nature of the carbon source applied and/or changes in the Dhc associated partners that fostered different biogeochemical conditions across the columns.
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Kleindienst S, Higgins SA, Tsementzi D, Chen G, Konstantinidis KT, Mack EE, Löffler FE. 'Candidatus Dichloromethanomonas elyunquensis' gen. nov., sp. nov., a dichloromethane-degrading anaerobe of the Peptococcaceae family. Syst Appl Microbiol 2016; 40:150-159. [PMID: 28292625 DOI: 10.1016/j.syapm.2016.12.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 12/02/2016] [Accepted: 12/09/2016] [Indexed: 12/22/2022]
Abstract
Taxonomic assignments of anaerobic dichloromethane (DCM)-degrading bacteria remain poorly constrained but are important for understanding the microbial diversity of organisms contributing to DCM turnover in environmental systems. We describe the taxonomic classification of a novel DCM degrader in consortium RM obtained from pristine Rio Mameyes sediment. Phylogenetic analysis of full-length 16S rRNA gene sequences demonstrated that the DCM degrader was most closely related to members of the genera Dehalobacter and Syntrophobotulus, but sequence similarities did not exceed 94% and 93%, respectively. Genome-aggregate average amino acid identities against Peptococcaceae members did not exceed 66%, suggesting that the DCM degrader does not affiliate with any described genus. Phylogenetic analysis of conserved single-copy functional genes supported that the DCM degrader represents a novel clade. Growth strictly depended on the presence of DCM, which was consumed at a rate of 160±3μmolL-1 d-1. The DCM degrader attained 5.25×107±1.0×107 cells per μmol DCM consumed. Fluorescence in situ hybridization revealed rod-shaped cells 4±0.8μm long and 0.4±0.1μm wide. Based on the unique phylogenetic, genomic, and physiological characteristics, we propose that the DCM degrader represents a new genus and species, 'Candidatus Dichloromethanomonas elyunquensis'.
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Affiliation(s)
- Sara Kleindienst
- University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA; Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN 37996, USA.
| | - Steven A Higgins
- University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA; Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN 37996, USA
| | - Despina Tsementzi
- Georgia Institute of Technology, School of Civil and Environmental Engineering, Atlanta, GA 30332, USA
| | - Gao Chen
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN 37996, USA; Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Konstantinos T Konstantinidis
- Georgia Institute of Technology, School of Civil and Environmental Engineering, Atlanta, GA 30332, USA; School of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - E Erin Mack
- Corporate Remediation Group, E. I. DuPont de Nemours and Company, Newark, DE 19714, USA
| | - Frank E Löffler
- University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA; Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN 37996, USA; Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USA.
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Chaussonnerie S, Saaidi PL, Ugarte E, Barbance A, Fossey A, Barbe V, Gyapay G, Brüls T, Chevallier M, Couturat L, Fouteau S, Muselet D, Pateau E, Cohen GN, Fonknechten N, Weissenbach J, Le Paslier D. Microbial Degradation of a Recalcitrant Pesticide: Chlordecone. Front Microbiol 2016; 7:2025. [PMID: 28066351 PMCID: PMC5167691 DOI: 10.3389/fmicb.2016.02025] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 12/02/2016] [Indexed: 01/17/2023] Open
Abstract
Chlordecone (Kepone®) is a synthetic organochlorine insecticide (C10Cl10O) used worldwide mostly during the 1970 and 1980s. Its intensive application in the French West Indies to control the banana black weevil Cosmopolites sordidus led to a massive environmental pollution. Persistence of chlordecone in soils and water for numerous decades even centuries causes global public health and socio-economic concerns. In order to investigate the biodegradability of chlordecone, microbial enrichment cultures from soils contaminated by chlordecone or other organochlorines and from sludge of a wastewater treatment plant have been conducted. Different experimental procedures including original microcosms were carried out anaerobically over long periods of time. GC-MS monitoring resulted in the detection of chlorinated derivatives in several cultures, consistent with chlordecone biotransformation. More interestingly, disappearance of chlordecone (50 μg/mL) in two bacterial consortia was concomitant with the accumulation of a major metabolite of formula C9Cl5H3 (named B1) as well as two minor metabolites C10Cl9HO (named A1) and C9Cl4H4 (named B3). Finally, we report the isolation and the complete genomic sequences of two new Citrobacter isolates, closely related to Citrobacter amalonaticus, and that were capable of reproducing chlordecone transformation. Further characterization of these Citrobacter strains should yield deeper insights into the mechanisms involved in this transformation process.
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Affiliation(s)
- Sébastien Chaussonnerie
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
| | - Pierre-Loïc Saaidi
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
| | - Edgardo Ugarte
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
| | - Agnès Barbance
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
| | - Aurélie Fossey
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
| | - Valérie Barbe
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de Génomique Evry, France
| | - Gabor Gyapay
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de Génomique Evry, France
| | - Thomas Brüls
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
| | - Marion Chevallier
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
| | - Loïc Couturat
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
| | - Stéphanie Fouteau
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de Génomique Evry, France
| | - Delphine Muselet
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
| | - Emilie Pateau
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
| | | | - Nuria Fonknechten
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
| | - Jean Weissenbach
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
| | - Denis Le Paslier
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction de la Recherche Fondamentale, Institut de GénomiqueEvry, France; Université d'Evry Val d'EssonneEvry, France; Centre National de la Recherche Scientifique, UMR8030, Génomique métaboliqueEvry, France
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Suzuki K, Owen R, Mok J, Mochihara H, Hosokawa T, Kubota H, Sakamoto H, Matsuda A, Tashiro Y, Futamata H. Comparison of electrochemical and microbiological characterization of microbial fuel cells equipped with SPEEK and Nafion membrane electrode assemblies. J Biosci Bioeng 2016; 122:322-8. [DOI: 10.1016/j.jbiosc.2016.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 02/01/2016] [Accepted: 02/09/2016] [Indexed: 11/28/2022]
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Dalvi S, Youssef NH, Fathepure BZ. Microbial community structure analysis of a benzoate-degrading halophilic archaeal enrichment. Extremophiles 2016; 20:311-21. [PMID: 26995683 DOI: 10.1007/s00792-016-0823-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/01/2016] [Indexed: 02/01/2023]
Abstract
A benzoate-degrading archaeal enrichment was developed using sediment samples from Rozel Point at Great Salt Lake, UT. The enrichment degraded benzoate as the sole carbon source at salinity ranging from 2.0 to 5.0 M NaCl with highest rate of degradation observed at 4.0 M. The enrichment was also tested for its ability to grow on other aromatic compounds such as 4-hydroxybenzoic acid (4-HBA), gentisic acid, protocatechuic acid (PCA), catechol, benzene and toluene as the sole sources of carbon and energy. Of these, the culture only utilized 4-HBA as the carbon source. To determine the initial steps in benzoate degradation pathway, a survey of ring-oxidizing and ring-cleaving genes was performed using degenerate PCR primers. Results showed the presence of 4-hydroxybenzoate 3-monooxygenase (4-HBMO) and protocatechuate 3, 4-dioxygenase (3,4-PCA) genes suggesting that the archaeal enrichment might degrade benzoate to 4-HBA that is further converted to PCA by 4-HBMO and, thus, formed PCA would undergo ring-cleavage by 3,4-PCA to form intermediates that enter the Krebs cycle. Small subunit rRNA gene-based diversity survey revealed that the enrichment consisted entirely of class Halobacteria members belonging to the genera Halopenitus, Halosarcina, Natronomonas, Halosimplex, Halorubrum, Salinarchaeum and Haloterrigena. Of these, Halopenitus was the dominant group accounting for almost 91 % of the total sequences suggesting their potential role in degrading oxygenated aromatic compounds at extreme salinity.
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Affiliation(s)
- Sonal Dalvi
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Noha H Youssef
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Babu Z Fathepure
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA.
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Cápiro NL, Löffler FE, Pennell KD. Spatial and temporal dynamics of organohalide-respiring bacteria in a heterogeneous PCE-DNAPL source zone. JOURNAL OF CONTAMINANT HYDROLOGY 2015; 182:78-90. [PMID: 26348832 DOI: 10.1016/j.jconhyd.2015.08.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 08/15/2015] [Accepted: 08/19/2015] [Indexed: 06/05/2023]
Abstract
Effective treatment of sites contaminated with dense non-aqueous phase liquids (DNAPLs) requires detailed understanding of the microbial community responses to changes in source zone strength and architecture. Changes in the spatial and temporal distributions of the organohalide-respiring Dehalococcoides mccartyi (Dhc) strains and Geobacter lovleyi strain SZ (GeoSZ) were examined in a heterogeneous tetrachloroethene- (PCE-) DNAPL source zone within a two-dimensional laboratory-scale aquifer flow cell. As part of a combined remedy approach, flushing with 2.3 pore volumes (PVs) of 4% (w/w) solution of the nonionic, biodegradable surfactant Tween® 80 removed 55% of the initial contaminant mass, and resulted in a PCE-DNAPL distribution that contained 51% discrete ganglia and 49% pools (ganglia-to-pool ratio of 1.06). Subsequent bioaugmentation with the PCE-to-ethene-dechlorinating consortium BDI-SZ resulted in cis-1,2-dichloroethene (cis-DCE) formation after 1 PV (ca. 7 days), while vinyl chloride (VC) and ethene were detected 10 PVs after bioaugmentation. Maximum ethene yields (ca. 90 μM) within DNAPL pool and ganglia regions coincided with the detection of the vcrA reductive dehalogenase (RDase) gene that exceeded the Dhc 16S rRNA genes by 2.0±1.3 and 4.0±1.7 fold in the pool and ganglia regions, respectively. Dhc and GeoSZ cell abundance increased by up to 4 orders-of-magnitude after 28 PVs of steady-state operation, with 1 to 2 orders-of-magnitude increases observed in close proximity to residual PCE-DNAPL. These observations suggest the involvement of these dechlorinators the in observed PCE dissolution enhancements of up to 2.3 and 6.0-fold within pool and ganglia regions, respectively. Analysis of the solid and aqueous samples at the conclusion of the experiment revealed that the highest VC (≥155 μM) and ethene (≥65 μM) concentrations were measured in zones where Dhc and GeoSZ were predominately attached to the solids. These findings demonstrate dynamic responses of organohalide-respiring bacteria in a heterogeneous DNAPL source zone, and emphasize the influence of source zone architecture on bioremediation performance.
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Affiliation(s)
- Natalie L Cápiro
- Department of Civil and Environmental Engineering, Tufts University, Medford, MA 02155, United States.
| | - Frank E Löffler
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States; Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, United States; Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN 37996, United States; University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
| | - Kurt D Pennell
- Department of Civil and Environmental Engineering, Tufts University, Medford, MA 02155, United States.
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Dehalogenimonas sp. Strain WBC-2 Genome and Identification of Its trans-Dichloroethene Reductive Dehalogenase, TdrA. Appl Environ Microbiol 2015; 82:40-50. [PMID: 26452554 DOI: 10.1128/aem.02017-15] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/06/2015] [Indexed: 02/04/2023] Open
Abstract
The Dehalogenimonas population in a dechlorinating enrichment culture referred to as WBC-2 was previously shown to be responsible for trans-dichloroethene (tDCE) hydrogenolysis to vinyl chloride (VC). In this study, blue native polyacrylamide gel electrophoresis (BN-PAGE) followed by enzymatic assays and protein identification using liquid chromatography coupled with mass spectrometry (LC-MS/MS) led to the functional characterization of a novel dehalogenase, TdrA. This new reductive dehalogenase (RDase) catalyzes the dechlorination of tDCE to VC. A metagenome of the WBC-2 culture was sequenced, and a complete Dehalogenimonas genome, only the second Dehalogenimonas genome to become publicly available, was closed. The tdrA dehalogenase found within the Dehalogenimonas genome appears to be on a genomic island similar to genomic islands found in Dehalococcoides. TdrA itself is most similar to TceA from Dehalococcoides sp. strain FL2 with 76.4% amino acid pairwise identity. It is likely that the horizontal transfer of rdhA genes is not only a feature of Dehalococcoides but also a feature of other Dehalococcoidia, including Dehalogenimonas. A set of primers was developed to track tdrA in WBC-2 subcultures maintained on different electron acceptors. This newest dehalogenase is an addition to the short list of functionally defined RDases sharing the usual characteristic motifs (including an AB operon, a TAT export sequence, two iron-sulfur clusters, and a corrinoid binding domain), substrate flexibility, and evidence for horizontal gene transfer within the Dehalococcoidia.
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27
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Jugder BE, Ertan H, Lee M, Manefield M, Marquis CP. Reductive Dehalogenases Come of Age in Biological Destruction of Organohalides. Trends Biotechnol 2015; 33:595-610. [DOI: 10.1016/j.tibtech.2015.07.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/27/2015] [Accepted: 07/30/2015] [Indexed: 11/28/2022]
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28
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Teng L, Wang K, Xu J, Xu C. Flavin mononucleotide (FMN)-based fluorescent protein (FbFP) as reporter for promoter screening in Clostridium cellulolyticum. J Microbiol Methods 2015; 119:37-43. [PMID: 26427827 DOI: 10.1016/j.mimet.2015.09.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/28/2015] [Accepted: 09/28/2015] [Indexed: 12/13/2022]
Abstract
Conventional methods for screening promoters in anaerobic bacteria are generally based on detection of enzymatic reactions and thus usually complicated or strain specific. Therefore a more efficient and universal method will be valuable. Here, using cellulolytic bacteria Clostridium cellulolyticum H10 as a model, we employed an oxygen-independent flavin-based fluorescent protein (FbFP) derived from Pseudomonas putida as a quantitative reporter for the screening of promoter via monitoring fluorescence intensity. The stability and reliability of FbFP fluorescence were proven by the high correlation (R(2)=0.87) between fluorescence intensity and abundance of FbFP. Moreover, two endogenous promoters with exceptional performance were identified and characterized, including a constitutive promoter p3398 and an inducible promoter p1133. Compared to the existing reporter systems widely used in clostridia, this FbFP-based method is more rapid, intuitive and versatile, and the endogenous promoters reported here should enrich the synthetic biology toolbox for this and related organisms.
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Affiliation(s)
- Lin Teng
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kun Wang
- Key Laboratory of Horticulture Science for Southern Mountainous Region, Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400716, China
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China.
| | - Chenggang Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China.
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Im J, Prevatte CW, Campagna SR, Löffler FE. Identification of 4-Hydroxycumyl Alcohol As the Major MnO2-Mediated Bisphenol A Transformation Product and Evaluation of Its Environmental Fate. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:6214-6221. [PMID: 25919646 DOI: 10.1021/acs.est.5b00372] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Bisphenol A (BPA), an environmental contaminant with weak estrogenic activity, resists microbial degradation under anoxic conditions but is susceptible to abiotic transformation by manganese dioxide (MnO2). BPA degradation followed pseudo-first-order kinetics with a rate constant of 0.96 (±0.03) min(-1) in the presence of 2 mM MnO2 (0.017% w/w) at pH 7.2. 4-hydroxycumyl alcohol (HCA) was the major transformation product, and, on a molar basis, up to 64% of the initial amount of BPA was recovered as HCA. MnO2 was also reactive toward HCA, albeit at 5-fold lower rates, and CO2 evolution (i.e., mineralization) occurred. In microcosms established with freshwater sediment, HCA was rapidly biodegraded under oxic, but not anoxic conditions. With a measured octanol-water partition coefficient (Log K(ow)) of 0.76 and an aqueous solubility of 2.65 g L(-1), HCA is more mobile in saturated media than BPA (Log K(ow) = 2.76; aqueous solubility = 0.31 g L(-1)), and therefore more likely to encounter oxic zones and undergo aerobic biodegradation. These findings corroborate that BPA is not inert under anoxic conditions and suggest that MnO2-mediated coupled abiotic-biotic processes may be relevant for controlling the fate and longevity of BPA in sediments and aquifers.
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Affiliation(s)
- Jeongdae Im
- †Department of Microbiology, University of Tennessee, Knoxville, Tennessee 37996, United States
- ‡Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Carson W Prevatte
- §Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Shawn R Campagna
- §Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Frank E Löffler
- †Department of Microbiology, University of Tennessee, Knoxville, Tennessee 37996, United States
- ‡Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
- ∥Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
- ⊥University of Tennessee and Oak RidgeNational Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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Justicia-Leon SD, Higgins S, Mack EE, Griffiths DR, Tang S, Edwards EA, Löffler FE. Bioaugmentation with distinct Dehalobacter strains achieves chloroform detoxification in microcosms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:1851-1858. [PMID: 24392834 DOI: 10.1021/es403582f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Chloroform (CF) is a widespread groundwater contaminant not susceptible to aerobic degradation. Under anoxic conditions, CF can undergo abiotic and cometabolic transformation but detoxification is generally not achieved. The recent discovery of distinct Dehalobacter strains that respire CF to dichloromethane (DCM) and ferment DCM to nonchlorinated products promises that bioremediation of CF plumes is feasible. To track both strains, 16S rRNA gene-based qPCR assays specific for either Dehalobacter strain were designed and validated. A laboratory treatability study explored the value of bioaugmentation and biostimulation to achieve CF detoxification using anoxic microcosms established with aquifer material from a CF-contaminated site. Microcosms that received 6% (v/v) of the CF-to-DCM-dechlorinating culture Dhb-CF to achieve an initial Dehalobacter cell titer of 1.6 ± 0.9 × 10(4) mL(-1) dechlorinated CF to stoichiometric amounts of DCM. Subsequent augmentation with 3% (v/v) of the DCM-degrading consortium RM to an initial Dehalobacter cell abundance of 1.2 ± 0.2 × 10(2) mL(-1) achieved complete DCM degradation in microcosms amended with 10 mM bicarbonate. Growth of the CF-respiring and the DCM-degrading Dehalobacter populations and detoxification were also observed in microcosms that received both inocula simultaneously. These findings suggest that anaerobic bioremediation (e.g., bioaugmentation) is a possible remedy at CF- and DCM-contaminated sites without CT, which strongly inhibited CF organohalide respiration and DCM organohalide fermentation.
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Hug LA, Edwards EA. Diversity of reductive dehalogenase genes from environmental samples and enrichment cultures identified with degenerate primer PCR screens. Front Microbiol 2013; 4:341. [PMID: 24312087 PMCID: PMC3832961 DOI: 10.3389/fmicb.2013.00341] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 10/29/2013] [Indexed: 01/11/2023] Open
Abstract
Reductive dehalogenases are the critical enzymes for anaerobic organohalide respiration, a microbial metabolic process that has been harnessed for bioremediation efforts to resolve chlorinated solvent contamination in groundwater and is implicated in the global halogen cycle. Reductive dehalogenase sequence diversity is informative for the dechlorination potential of the site or enrichment culture. A suite of degenerate PCR primers targeting a comprehensive curated set of reductive dehalogenase genes was designed and applied to 12 DNA samples extracted from contaminated and pristine sites, as well as six enrichment cultures capable of reducing chlorinated compounds to non-toxic end-products. The amplified gene products from four environmental sites and two enrichment cultures were sequenced using Illumina HiSeq, and the reductive dehalogenase complement of each sample determined. The results indicate that the diversity of the reductive dehalogenase gene family is much deeper than is currently accounted for: one-third of the translated proteins have less than 70% pairwise amino acid identity to database sequences. Approximately 60% of the sequenced reductive dehalogenase genes were broadly distributed, being identified in four or more samples, and often in previously sequenced genomes as well. In contrast, 17% of the sequenced reductive dehalogenases were unique, present in only a single sample and bearing less than 90% pairwise amino acid identity to any previously identified proteins. Many of the broadly distributed reductive dehalogenases are uncharacterized in terms of their substrate specificity, making these intriguing targets for further biochemical experimentation. Finally, comparison of samples from a contaminated site and an enrichment culture derived from the same site 8 years prior allowed examination of the effect of the enrichment process.
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Affiliation(s)
- Laura A Hug
- Department of Cell and Systems Biology, University of Toronto Toronto, ON, Canada
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Identification and environmental distribution of dcpA, which encodes the reductive dehalogenase catalyzing the dichloroelimination of 1,2-dichloropropane to propene in organohalide-respiring chloroflexi. Appl Environ Microbiol 2013; 80:808-18. [PMID: 24242248 DOI: 10.1128/aem.02927-13] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dehalococcoides mccartyi strains KS and RC grow with 1,2-dichloropropane (1,2-D) as an electron acceptor in enrichment cultures derived from hydrocarbon-contaminated and pristine river sediments, respectively. Transcription, expression, enzymatic, and PCR analyses implicated the reductive dehalogenase gene dcpA in 1,2-D dichloroelimination to propene and inorganic chloride. Quantitative real-time PCR (qPCR) analyses demonstrated a D. mccartyi cell increase during growth with 1,2-D and suggested that both D. mccartyi strains carried a single dcpA gene copy per genome. D. mccartyi strain RC and strain KS produced 1.8 × 10(7) ± 0.1 × 10(7) and 1.4 × 10(7) ± 0.5 × 10(7) cells per μmol of propene formed, respectively. The dcpA gene was identified in 1,2-D-to-propene-dechlorinating microcosms established with sediment samples collected from different geographical locations in Europe and North and South America. Clone library analysis revealed two distinct dcpA phylogenetic clusters, both of which were captured by the dcpA gene-targeted qPCR assay, suggesting that the qPCR assay is useful for site assessment and bioremediation monitoring at 1,2-D-contaminated sites.
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Xu C, Huang R, Teng L, Wang D, Hemme CL, Borovok I, He Q, Lamed R, Bayer EA, Zhou J, Xu J. Structure and regulation of the cellulose degradome in Clostridium cellulolyticum. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:73. [PMID: 23657055 PMCID: PMC3656788 DOI: 10.1186/1754-6834-6-73] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 05/01/2013] [Indexed: 05/20/2023]
Abstract
BACKGROUND Many bacteria efficiently degrade lignocellulose yet the underpinning genome-wide metabolic and regulatory networks remain elusive. Here we revealed the "cellulose degradome" for the model mesophilic cellulolytic bacterium Clostridium cellulolyticum ATCC 35319, via an integrated analysis of its complete genome, its transcriptomes under glucose, xylose, cellobiose, cellulose, xylan or corn stover and its extracellular proteomes under glucose, cellobiose or cellulose. RESULTS Proteins for core metabolic functions, environment sensing, gene regulation and polysaccharide metabolism were enriched in the cellulose degradome. Analysis of differentially expressed genes revealed a "core" set of 48 CAZymes required for degrading cellulose-containing substrates as well as an "accessory" set of 76 CAZymes required for specific non-cellulose substrates. Gene co-expression analysis suggested that Carbon Catabolite Repression (CCR) related regulators sense intracellular glycolytic intermediates and control the core CAZymes that mainly include cellulosomal components, whereas 11 sets of Two-Component Systems (TCSs) respond to availability of extracellular soluble sugars and respectively regulate most of the accessory CAZymes and associated transporters. Surprisingly, under glucose alone, the core cellulases were highly expressed at both transcript and protein levels. Furthermore, glucose enhanced cellulolysis in a dose-dependent manner, via inducing cellulase transcription at low concentrations. CONCLUSION A molecular model of cellulose degradome in C. cellulolyticum (Ccel) was proposed, which revealed the substrate-specificity of CAZymes and the transcriptional regulation of core cellulases by CCR where the glucose acts as a CCR inhibitor instead of a trigger. These features represent a distinct environment-sensing strategy for competing while collaborating for cellulose utilization, which can be exploited for process and genetic engineering of microbial cellulolysis.
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Affiliation(s)
- Chenggang Xu
- BioEnergy Genome Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Ranran Huang
- BioEnergy Genome Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Lin Teng
- BioEnergy Genome Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Dongmei Wang
- BioEnergy Genome Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Christopher L Hemme
- Institute for Environmental Genomics, Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73072, USA
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Qiang He
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Edward A Bayer
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Jizhong Zhou
- Institute for Environmental Genomics, Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73072, USA
| | - Jian Xu
- BioEnergy Genome Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
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Electricity producing property and bacterial community structure in microbial fuel cell equipped with membrane electrode assembly. J Biosci Bioeng 2013; 116:106-13. [PMID: 23490643 DOI: 10.1016/j.jbiosc.2013.01.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 01/09/2013] [Accepted: 01/24/2013] [Indexed: 11/22/2022]
Abstract
It is important for practical use of microbial fuel cells (MFCs) to not only develop electrodes and proton exchange membranes but also to understand the bacterial community structure related to electricity generation. Four lactate fed MFCs equipped with different membrane electrode assemblies (MEAs) were constructed with paddy field soil as inoculum. The MEAs significantly affected the electricity-generating properties of the MFCs. MEA-I was made with Nafion 117 solution and the other MEAs were made with different configurations of three kinds of polymers. MFC-I equipped with MEA-I exhibited the highest performance with a stable current density of 55 ± 3 mA m⁻². MFC-III equipped with MEA-III with the highest platinum concentration, exhibited the lowest performance with a stable current density of 1.7 ± 0.1 mA m⁻². SEM observation revealed that there were cracks on MEA-III. These results demonstrated that it is significantly important to prevent oxygen-intrusion for improved MFC performance. By comparing the data of DGGE and phylogenetic analyzes, it was suggested that the dominant bacterial communities of MFC-I were constructed with lactate-fermenters and Fe(III)-reducers, which consisted of bacteria affiliated with the genera of Enterobacter, Dechlorosoma, Pelobacter, Desulfovibrio, Propioniferax, Pelosinus, and Firmicutes. A bacterium sharing 100% similarity to one of the DGGE bands was isolated from MFC-I. The 16S rRNA gene sequence of the isolate shared 98% similarity to gram-positive Propioniferax sp. P7 and it was confirmed that the isolate produced electricity in an MFC. These results suggested that these bacteria are valuable for constructing the electron transfer network in MFC.
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35
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Hug LA, Maphosa F, Leys D, Löffler FE, Smidt H, Edwards EA, Adrian L. Overview of organohalide-respiring bacteria and a proposal for a classification system for reductive dehalogenases. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120322. [PMID: 23479752 DOI: 10.1098/rstb.2012.0322] [Citation(s) in RCA: 193] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Organohalide respiration is an anaerobic bacterial respiratory process that uses halogenated hydrocarbons as terminal electron acceptors during electron transport-based energy conservation. This dechlorination process has triggered considerable interest for detoxification of anthropogenic groundwater contaminants. Organohalide-respiring bacteria have been identified from multiple bacterial phyla, and can be categorized as obligate and non-obligate organohalide respirers. The majority of the currently known organohalide-respiring bacteria carry multiple reductive dehalogenase genes. Analysis of a curated set of reductive dehalogenases reveals that sequence similarity and substrate specificity are generally not correlated, making functional prediction from sequence information difficult. In this article, an orthologue-based classification system for the reductive dehalogenases is proposed to aid integration of new sequencing data and to unify terminology.
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Affiliation(s)
- Laura A Hug
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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36
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Villemur R. The pentachlorophenol-dehalogenating Desulfitobacterium hafniense strain PCP-1. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120319. [PMID: 23479749 DOI: 10.1098/rstb.2012.0319] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In this report, a complete description of Desulfitobacterium hafniense strain PCP-1 is presented. The D. hafniense strain PCP-1 was isolated from a methanogenic consortium for its capacity to dehalogenate pentachlorophenol (PCP) into 3-chlorophenol. This strain is also capable of dehalogenating several other chloroaromatic compounds and tetrachloroethene into trichloroethene. Four gene loci encoding putative chlorophenol-reductive dehalogenases (CprA2 to CprA5) were detected, and the products of two of these loci have been demonstrated to dechlorinate different chlorinated phenols. Strain PCP-1 was used in laboratory-scale bioprocesses to degrade PCP present in contaminated environments. Desulfitobacterium hafniense PCP-1 is an excellent candidate for the development of efficient bioprocesses to degrade organohalide compounds.
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Affiliation(s)
- Richard Villemur
- INRS institut Armand-Frappier, 531 Boulevard des Prairies, Laval, Quebec, Canada, H7V 1B7.
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37
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Gregoire KP, Becker JG. Design and characterization of a microbial fuel cell for the conversion of a lignocellulosic crop residue to electricity. BIORESOURCE TECHNOLOGY 2012; 119:208-215. [PMID: 22728202 DOI: 10.1016/j.biortech.2012.05.075] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 05/14/2012] [Accepted: 05/16/2012] [Indexed: 06/01/2023]
Abstract
Agricultural crop residues contain high amounts of biochemical energy as cellulose and lignin. A portion of this biomass could be sustainably harvested for conversion to bioenergy to help offset fossil fuel consumption. In this study, the potential for converting lignocellulosic biomass directly to electricity in a microbial fuel cell (MFC) was explored. Design elements of tubular air cathode MFCs and leach-bed bioreactors were integrated to develop a new solid-substrate MFC in which cellulose hydrolysis, fermentation, and anode respiration occurred in a single chamber. Electricity was produced continuously from untreated corncob pellets for >60 d. Addition of rumen fluid increased power production, presumably by providing growth factors to anode-respiring bacteria. Periodic exposure to oxygen also increased power production, presumably by limiting the diversion of electrons to methanogenesis. In the absence of methanogenesis, bioaugmentation with Geobacter metallireducens further improved MFC performance. Under these conditions, the maximum power density was 230 mW/m(3).
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Affiliation(s)
- K P Gregoire
- Department of Civil & Environmental Engineering, University of Maryland, College Park, College Park, MD 20742, USA
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Ding C, He J. Molecular techniques in the biotechnological fight against halogenated compounds in anoxic environments. Microb Biotechnol 2012; 5:347-67. [PMID: 22070763 PMCID: PMC3821678 DOI: 10.1111/j.1751-7915.2011.00313.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 09/24/2011] [Accepted: 09/28/2011] [Indexed: 11/28/2022] Open
Abstract
Microbial treatment of environmental contamination by anthropogenic halogenated organic compounds has become popular in recent decades, especially in the subsurface environments. Molecular techniques such as polymerase chain reaction-based fingerprinting methods have been extensively used to closely monitor the presence and activities of dehalogenating microbes, which also lead to the discovery of new dehalogenating bacteria and novel functional genes. Nowadays, traditional molecular techniques are being further developed and optimized for higher sensitivity, specificity, and accuracy to better fit the contexts of dehalogenation. On the other hand, newly developed high throughput techniques, such as microarray and next-generation sequencing, provide unsurpassed detection ability, which has enabled large-scale comparative genomic and whole-genome transcriptomic analysis. The aim of this review is to summarize applications of various molecular tools in the field of microbially mediated dehalogenation of various halogenated organic compounds. It is expected that traditional molecular techniques and nucleic-acid-based biomarkers will still be favoured in the foreseeable future because of relative low costs and high flexibility. Collective analyses of metagenomic sequencing data are still in need of information from individual dehalogenating strains and functional reductive dehalogenase genes in order to draw reliable conclusions.
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Affiliation(s)
| | - Jianzhong He
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore 117576
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Genome sequence of Desulfitobacterium hafniense DCB-2, a Gram-positive anaerobe capable of dehalogenation and metal reduction. BMC Microbiol 2012; 12:21. [PMID: 22316246 PMCID: PMC3306737 DOI: 10.1186/1471-2180-12-21] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 02/08/2012] [Indexed: 12/13/2022] Open
Abstract
Background The genome of the Gram-positive, metal-reducing, dehalorespiring Desulfitobacterium hafniense DCB-2 was sequenced in order to gain insights into its metabolic capacities, adaptive physiology, and regulatory machineries, and to compare with that of Desulfitobacterium hafniense Y51, the phylogenetically closest strain among the species with a sequenced genome. Results The genome of Desulfitobacterium hafniense DCB-2 is composed of a 5,279,134-bp circular chromosome with 5,042 predicted genes. Genome content and parallel physiological studies support the cell's ability to fix N2 and CO2, form spores and biofilms, reduce metals, and use a variety of electron acceptors in respiration, including halogenated organic compounds. The genome contained seven reductive dehalogenase genes and four nitrogenase gene homologs but lacked the Nar respiratory nitrate reductase system. The D. hafniense DCB-2 genome contained genes for 43 RNA polymerase sigma factors including 27 sigma-24 subunits, 59 two-component signal transduction systems, and about 730 transporter proteins. In addition, it contained genes for 53 molybdopterin-binding oxidoreductases, 19 flavoprotein paralogs of the fumarate reductase, and many other FAD/FMN-binding oxidoreductases, proving the cell's versatility in both adaptive and reductive capacities. Together with the ability to form spores, the presence of the CO2-fixing Wood-Ljungdahl pathway and the genes associated with oxygen tolerance add flexibility to the cell's options for survival under stress. Conclusions D. hafniense DCB-2's genome contains genes consistent with its abilities for dehalogenation, metal reduction, N2 and CO2 fixation, anaerobic respiration, oxygen tolerance, spore formation, and biofilm formation which make this organism a potential candidate for bioremediation at contaminated sites.
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40
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Dichloromethane fermentation by a Dehalobacter sp. in an enrichment culture derived from pristine river sediment. Appl Environ Microbiol 2011; 78:1288-91. [PMID: 22179245 DOI: 10.1128/aem.07325-11] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dichloromethane (DCM) as the sole substrate supported growth of a Dehalobacter sp. in an enrichment culture derived from noncontaminated river sediment. DCM was not reductively dechlorinated, and acetate was produced, indicating DCM fermentation and further suggesting Dehalobacter growth is not limited to organohalide respiration.
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41
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Chang YC, Ikeutsu K, Toyama T, Choi D, Kikuchi S. Isolation and characterization of tetrachloroethylene- and cis-1,2-dichloroethylene-dechlorinating propionibacteria. J Ind Microbiol Biotechnol 2011; 38:1667-77. [DOI: 10.1007/s10295-011-0956-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Accepted: 03/05/2011] [Indexed: 11/28/2022]
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Fletcher KE, Costanza J, Cruz-Garcia C, Ramaswamy NS, Pennell KD, Löffler FE. Effects of elevated temperature on Dehalococcoides dechlorination performance and DNA and RNA biomarker abundance. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:712-718. [PMID: 21126083 DOI: 10.1021/es1023477] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Coupling thermal treatment with microbial reductive dechlorination is a promising remedy for tetrachloroethene (PCE) and trichloroethene (TCE) contaminated source zones. Laboratory experiments evaluated Dehalococcoides (Dhc) dechlorination performance, viability, and biomarker gene (DNA) and transcript (mRNA) abundances during exposure to elevated temperatures. The PCE-dechlorinating consortia BDI and OW produced ethene when incubated at temperatures of 30 °C, but vinyl chloride (VC) accumulated when cultures were incubated at 35 or 40 °C. Cultures incubated at 40 °C for less than 49 days resumed VC dechlorination following cooling; however, incubation at 45 °C resulted in complete loss of dechlorination activity. Dhc 16S rRNA, bvcA, and vcrA gene abundances in cultures showing complete dechlorination to ethene at 30 °C exceeded those measured in cultures incubated at higher temperatures, consistent with observed dechlorination activities. Conversely, biomarker gene transcript abundances per cell in cultures incubated at 35 and 40 °C were generally at least one order-of-magnitude greater than those measured in ethene-producing cultures incubated at 30 °C. Even in cultures accumulating VC, transcription of the vcrA gene, which is implicated in VC-to-ethene dechlorination, was up-regulated. Temperature stress caused the up-regulation of Dhc reductive dehalogenase gene expression indicating that Dhc gene expression measurements should be interpreted cautiously as Dhc biomarker gene transcript abundances may not correlate with dechlorination activity.
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Affiliation(s)
- Kelly E Fletcher
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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43
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Characterization of microbial community structure and population dynamics of tetrachloroethene-dechlorinating tidal mudflat communities. Biodegradation 2010; 22:687-98. [DOI: 10.1007/s10532-010-9429-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Accepted: 10/14/2010] [Indexed: 02/04/2023]
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44
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Identification and characterization of a novel CprA reductive dehalogenase specific to highly chlorinated phenols from Desulfitobacterium hafniense strain PCP-1. Appl Environ Microbiol 2010; 76:7536-40. [PMID: 20870790 DOI: 10.1128/aem.01362-10] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Desulfitobacterium hafniense strain PCP-1 reductively dechlorinates pentachlorophenol (PCP) to 3-chlorophenol and a variety of halogenated aromatic compounds at the ortho, meta, and para positions. Several reductive dehalogenases (RDases) are thought to be involved in this cascade of dehalogenation. We partially purified a novel RDase involved in the dechlorination of highly chlorinated phenols from strain PCP-1 cultivated in the presence of 2,4,6-trichlorophenol. The RDase was membrane associated, and the activity was sensitive to oxygen, with a half-life of 128 min upon exposure to air. The pH and temperature optima were 7.0 and 55°C, respectively. Several highly chlorinated phenols were dechlorinated at the ortho positions. The highest dechlorinating activity levels were observed with PCP, 2,3,4,5-tetrachlorophenol, and 2,3,4-trichlorophenol. 3-Chloro-4-hydroxyphenylacetate, 3-chloro-4-hydroxybenzoate, dichlorophenols, and monochlorophenols were not dechlorinated. The apparent K(m) value for PCP was 46.7 μM at a methyl viologen concentration of 2 mM. A mixture of iodopropane and titanium citrate caused a light-reversible inhibition of the dechlorinating activity, suggesting the involvement of a corrinoid cofactor. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the partially purified preparation revealed 2 bands with apparent molecular masses of 42 and 47 kDa. Mass spectrometry analysis using Mascot to search the genome sequence of D. hafniense strain DCB-2 identified the 42-kDa band as NADH-quinone oxidoreductase, subunit D, and the 47-kDa band as the putative chlorophenol RDase CprA3. This is the first report of an RDase with high affinity and high dechlorinating activity toward PCP.
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45
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Zhang H, Ziv-El M, Rittmann BE, Krajmalnik-Brown R. Effect of dechlorination and sulfate reduction on the microbial community structure in denitrifying membrane-biofilm reactors. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:5159-5164. [PMID: 20524654 DOI: 10.1021/es100695n] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Recent studies showed that the chlorinated solvents trichloroethene (TCE), 1,1,1-trichloroethane (TCA), and chloroform (CF) were reductively dehalogenated in a H(2)-based membrane biofilm reactor (MBfR) under denitrifying conditions. Here, we describe a detailed phylogenetic characterization of MBfR biofilm communities having distinctly different metabolic functions with respect to electron-acceptor reduction. Using massively parallel pyrosequencing of the V6 region of the 16S rRNA gene, we detected 312, 592, and 639 operational taxonomic units (OTU) in biofilms of three MBfRs that reduced nitrate; nitrate and TCE; or nitrate, sulfate, and all three chlorinated solvents. Comparative community analysis revealed that 13% of the OTUs were shared by all MBfRs, regardless of the feed, but 65% were unique to one MBfR. Pyrosequencing and real-time quantitative PCR showed that Dehalococcoides were markedly enriched in the TCE+nitrate biofilm. The input of a mixture of three chlorinated compounds, which coincided with the onset of sulfate reduction, led to a more diverse community that included sulfate-reducing bacteria (Desulfovibrio) and nitrate-reducing bacteria (Geothrix and Pseudomonas). Our results suggest that chlorinated solvents, as additional electron acceptors to nitrate and sulfate, increased microbial diversity by allowing bacteria with special metabolic capabilities to grow in the biofilm.
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Affiliation(s)
- Husen Zhang
- Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, Arizona, 85287, USA
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Loffler FE, Champine JE, Ritalahti KM, Sprague SJ, Tiedje JM. Complete reductive dechlorination of 1,2-dichloropropane by anaerobic bacteria. Appl Environ Microbiol 2010; 63:2870-5. [PMID: 16535654 PMCID: PMC1389209 DOI: 10.1128/aem.63.7.2870-2875.1997] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The transformation of 1,2-dichloropropane (1,2-D) was observed in anaerobic microcosms and enrichment cultures derived from Red Cedar Creek sediment. 1-Chloropropane (1-CP) and 2-CP were detected after an incubation period of 4 weeks. After 4 months the initial amount of 1,2-D was stoichiometrically converted to propene, which was not further transformed. Dechlorination of 1,2-D was not inhibited by 2-bromoethanesulfonate. Sequential 5% (vol/vol) transfers from active microcosms yielded a sediment-free, nonmethanogenic culture, which completely dechlorinated 1,2-D to propene at a rate of 5 nmol min(sup-1) mg of protein(sup-1). No intermediate formation of 1-CP or 2-CP was detected in the sediment-free enrichment culture. A variety of electron donors, including hydrogen, supported reductive dechlorination of 1,2-D. The highest dechlorination rates were observed between 20(deg) and 25(deg)C. In the presence of 1,2-D, the hydrogen threshold concentration was below 1 ppm by volume (ppmv). In addition to 1,2-D, the enrichment culture transformed 1,1-D, 2-bromo-1-CP, tetrachloroethene, 1,1,2,2-tetrachloroethane, and 1,2-dichloroethane to less halogenated compounds. These findings extend our knowledge of the reductive dechlorination process and show that halogenated propanes can be completely dechlorinated by anaerobic bacteria.
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Rosner BM, McCarty PL, Spormann AM. In vitro studies on reductive vinyl chloride dehalogenation by an anaerobic mixed culture. Appl Environ Microbiol 2010; 63:4139-44. [PMID: 16535722 PMCID: PMC1389278 DOI: 10.1128/aem.63.11.4139-4144.1997] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Reductive dehalogenation of vinyl chloride (VC) was studied in an anaerobic mixed bacterial culture. In growth experiments, ethene formation from VC increased exponentially at a rate of about 0.019 h(sup-1). Reductive VC dehalogenation was measured in vitro by using cell extracts of the mixed culture. The apparent K(infm) for VC was determined to be about 76 (mu)M; the V(infmax) was about 28 nmol (middot) min(sup-1) (middot) mg of protein(sup-1). The VC-dehalogenating activity was membrane associated. Propyl iodide had an inhibitory effect on the VC-dehalogenating activity in the in vitro assay. However, this inhibition could not be reversed by illumination. Cell extracts also catalyzed the reductive dehalogenation of cis-1,2-dichloroethene (cis-DCE) and, at a lower rate, of trichloroethene (TCE). Tetrachloroethene (PCE) was not transformed. The results indicate that the reductive dehalogenation of VC and cis-DCE described here is different from previously reported reductive dehalogenation of PCE and TCE.
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Thomas SH, Sanford RA, Amos BK, Leigh MB, Cardenas E, Löffler FE. Unique ecophysiology among U(VI)-reducing bacteria as revealed by evaluation of oxygen metabolism in Anaeromyxobacter dehalogenans strain 2CP-C. Appl Environ Microbiol 2010; 76:176-83. [PMID: 19897758 PMCID: PMC2798628 DOI: 10.1128/aem.01854-09] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 11/02/2009] [Indexed: 11/20/2022] Open
Abstract
Anaeromyxobacter spp. respire soluble hexavalent uranium, U(VI), leading to the formation of insoluble U(IV), and are present at the uranium-contaminated Oak Ridge Integrated Field Research Challenge (IFC) site. Pilot-scale in situ bioreduction of U(VI) has been accomplished in area 3 of the Oak Ridge IFC site following biostimulation, but the susceptibility of the reduced material to oxidants (i.e., oxygen) compromises long-term U immobilization. Following oxygen intrusion, attached Anaeromyxobacter dehalogenans cells increased approximately 5-fold from 2.2x10(7)+/-8.6x10(6) to 1.0x10(8)+/-2.2x10(7) cells per g of sediment collected from well FW101-2. In the same samples, the numbers of cells of Geobacter lovleyi, a population native to area 3 and also capable of U(VI) reduction, decreased or did not change. A. dehalogenans cells captured via groundwater sampling (i.e., not attached to sediment) were present in much lower numbers (<1.3x10(4)+/-1.1x10(4) cells per liter) than sediment-associated cells, suggesting that A. dehalogenans cells occur predominantly in association with soil particles. Laboratory studies confirmed aerobic growth of A. dehalogenans strain 2CP-C at initial oxygen partial pressures (pO2) at and below 0.18 atm. A negative linear correlation [micro=(-0.09xpO2)+0.051; R2=0.923] was observed between the instantaneous specific growth rate micro and pO2, indicating that this organism should be classified as a microaerophile. Quantification of cells during aerobic growth revealed that the fraction of electrons released in electron donor oxidation and used for biomass production (fs) decreased from 0.52 at a pO2 of 0.02 atm to 0.19 at a pO2 of 0.18 atm. Hence, the apparent fraction of electrons utilized for energy generation (i.e., oxygen reduction) (fe) increased from 0.48 to 0.81 with increasing pO2, suggesting that oxygen is consumed in a nonrespiratory process at a high pO2. The ability to tolerate high oxygen concentrations, perform microaerophilic oxygen respiration, and preferentially associate with soil particles represents an ecophysiology that distinguishes A. dehalogenans from other known U(VI)-reducing bacteria in area 3, and these features may play roles for stabilizing immobilized radionuclides in situ.
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Affiliation(s)
- Sara H. Thomas
- School of Civil and Environmental Engineering, School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332-0512, Department of Geology, University of Illinois, Urbana, Illinois 61801-2352, Department of Biology and Wildlife and Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska 99775, Center for Microbial Ecology, Michigan State University, East Lansing, Michigan 48824
| | - Robert A. Sanford
- School of Civil and Environmental Engineering, School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332-0512, Department of Geology, University of Illinois, Urbana, Illinois 61801-2352, Department of Biology and Wildlife and Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska 99775, Center for Microbial Ecology, Michigan State University, East Lansing, Michigan 48824
| | - Benjamin K. Amos
- School of Civil and Environmental Engineering, School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332-0512, Department of Geology, University of Illinois, Urbana, Illinois 61801-2352, Department of Biology and Wildlife and Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska 99775, Center for Microbial Ecology, Michigan State University, East Lansing, Michigan 48824
| | - Mary Beth Leigh
- School of Civil and Environmental Engineering, School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332-0512, Department of Geology, University of Illinois, Urbana, Illinois 61801-2352, Department of Biology and Wildlife and Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska 99775, Center for Microbial Ecology, Michigan State University, East Lansing, Michigan 48824
| | - Erick Cardenas
- School of Civil and Environmental Engineering, School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332-0512, Department of Geology, University of Illinois, Urbana, Illinois 61801-2352, Department of Biology and Wildlife and Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska 99775, Center for Microbial Ecology, Michigan State University, East Lansing, Michigan 48824
| | - Frank E. Löffler
- School of Civil and Environmental Engineering, School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332-0512, Department of Geology, University of Illinois, Urbana, Illinois 61801-2352, Department of Biology and Wildlife and Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska 99775, Center for Microbial Ecology, Michigan State University, East Lansing, Michigan 48824
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Grostern A, Chan WWM, Edwards EA. 1,1,1-trichloroethane and 1,1-dichloroethane reductive dechlorination kinetics and co-contaminant effects in a Dehalobacter-containing mixed culture. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:6799-6807. [PMID: 19764252 DOI: 10.1021/es901038x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
1,1,1-Trichloroethane (1,1,1-TCA) is a common groundwater contaminant that can be reductively dechlorinated to 1,1-dichloroethane (1,1-DCA) and monochloroethane, and can support the growth of certain dehalorespiring strains of Dehalobacter We used reductive dehalogenase cell-free extract assays (with reduced methyl viologen) and whole cell suspension dechlorination assays (with hydrogen) and a Dehalobacter-containing enrichment culture to explore the kinetics of l,1,1-TCA and 1,1-DCA reductive dechlorination in the presence of the common co-contaminants trichloroethene (TCE), cis-dichloroethene (cDCE), and vinyl chloride (VC). These chlorinated ethenes were most significant inhibitors of 1,1,1-TCA dechlorination in cell-free extracts, indicating direct effects on the reductive dehalogenase enzyme(s). The inhibition was present but less pronounced in whole cell suspension assays. None of the chlorinated ethenes inhibited 1,1-DCA dechlorination in cell-free extract assays, yet cDCE and particularly VC were inhibitors in whole cell assays, indicating an effect on Dehalobacter, but not on the dehalogenase enzyme(s). Marked differences in kinetic parameters for 1,1,1-TCA and 1,1-DCA, and an uncoupling of these two activities in cultures grown on 1,1-DCA compared to those grown on 1,1,1-TCA was strong evidence for the existence of distinct 1,1,1-TCA and 1,1-DCA reductive dehalogenase enzymes.
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Affiliation(s)
- Ariel Grostern
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, Canada
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Kim MS, Roh SW, Nam YD, Yoon JH, Bae JW. Carnobacterium jeotgali sp. nov., isolated from a Korean traditional fermented food. Int J Syst Evol Microbiol 2009; 59:3168-71. [PMID: 19643884 DOI: 10.1099/ijs.0.010116-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A Gram-positive, facultatively anaerobic bacterium, designated strain MS3(T), was isolated from a traditional Korean fermented food made with freshwater shrimp. Strain MS3(T) was able to grow at 4-37 degrees C, at pH 5.5-9.0 and in the presence of 0-5 % (w/v) NaCl. Optimal growth occurred at 30 degrees C, at pH 8.5 and in the presence of 2 % NaCl. The strain was catalase- and oxidase-negative. It was able to metabolize various carbohydrates as energy sources. 16S rRNA gene sequence analysis showed that strain MS3(T) was most closely related to Carnobacterium pleistocenium FTR1(T) (98.95 % similarity), but the level of DNA-DNA relatedness between the two taxa was less than 16.0 %. The genomic G+C content of strain MS3(T) was 43.9 mol% and the major fatty acid components were C(16 : 0), C(16 : 1)omega9c and C(18 : 1)omega9c. On the basis of its genotypic, physiological and biochemical characteristics, strain MS3(T) is considered to represent a novel species of the genus Carnobacterium, for which the name Carnobacterium jeotgali sp. nov. is proposed. The type strain is MS3(T) (=KCTC 13251(T)=JCM 15539(T)).
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Affiliation(s)
- Min-Soo Kim
- Department of Life and Nanopharmaceutical Sciences and Department of Biology, Kyung Hee University, Seoul 130-701, Korea
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