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Qi S, Xu L, Su J, Li T, Wei H, Li X. Fe 3+/Fe 2+ cycling drove novel ammonia oxidation and simultaneously removed lead, cadmium, and copper. JOURNAL OF HAZARDOUS MATERIALS 2024; 480:136124. [PMID: 39405709 DOI: 10.1016/j.jhazmat.2024.136124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Revised: 09/28/2024] [Accepted: 10/08/2024] [Indexed: 12/01/2024]
Abstract
The discharge of several pollutants, such as ammonia (NH4+-N), nitrate (NO3--N), and heavy metals, from aquaculture wastewater into the aquatic environment can cause severe pollution issues. In this work, microbial techniques were employed to enable concurrent elimination of NH4+-N and NO3--N by Fe3+/Fe2+ cycling. The greatest NH4+-N and NO3--N removal efficiencies of 96.1 % and 97.6 % were gained by Aquabacterium sp. XL4 at NH4+/NO3- ratio of 1:1, carbon to nitrogen ratio of 4.0, pH of 6.5, and Fe3+ dosage of 20.0 mg L-1. Inhibitor and nitrogen balance assays suggested that nitrogen removal process of strain XL4 was a coupled function of anaerobic ammonia oxidation, ferric reduction driven ammonia oxidation, and iron-based denitrification. Furthermore, under the compound influence of strain XL4 metabolic processes and microbial iron oxide adsorption, the removal efficiencies of Pb2+, Cd2+, and Cu2+ reached above 90 %. This work contributes to theoretical grounding for microbial removal of multiple pollutants.
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Affiliation(s)
- Shangzhe Qi
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Liang Xu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Junfeng Su
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Tianmeng Li
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Hao Wei
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Xuan Li
- College of Environmental Science & Engineering, Yancheng Institute of Technology, Yancheng 224051, China
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2
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Zhang Z, Zhang Z, Zhang C, Chang Q, Fang Q, Liao C, Chen J, Alvarez PJJ, Chen W, Zhang T. Simultaneous Reduction and Methylation of Nanoparticulate Mercury: The Critical Role of Extracellular Electron Transfer. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:18368-18378. [PMID: 39370945 DOI: 10.1021/acs.est.4c07573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/08/2024]
Abstract
Mercury nanoparticles are abundant in natural environments. Yet, understanding their contribution to global biogeochemical cycling of mercury remains elusive. Here, we show that microbial transformation of nanoparticulate divalent mercury can be an important source of elemental and methylmercury.Geobacter sulfurreducensPCA, a model bacterium predominant in anoxic environments (e.g., paddy soils), simultaneously reduces and methylates nanoparticulate Hg(II). Moreover, the relative prevalence of these two competing processes and the dominant transformation pathways differ markedly between nanoparticulate Hg(II) and its dissolved and bulk-sized counterparts. Notably, even when intracellular reduction of Hg(II) nanoparticles is constrained by cross-membrane transport (a rate-limiting step that also regulates methylation), the overall Hg(0) formation remains substantial due to extracellular electron transfer. With multiple lines of evidence based on microscopic and electrochemical analyses, gene knockout experiments, and theoretical calculations, we show that nanoparticulate Hg(II) is preferentially associated with c-type cytochromes on cell membranes and has a higher propensity for accepting electrons from the heme groups than adsorbed ionic Hg(II), which explains the surprisingly larger extent of reduction of nanoparticles than dissolved Hg(II) at relatively high mercury loadings. These findings have important implications for the assessment of global mercury budgets as well as the bioavailability of nanominerals and mineral nanoparticles.
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Affiliation(s)
- Zhiying Zhang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Zhanhua Zhang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Chenyang Zhang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Qing Chang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Qingxuan Fang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Chengmei Liao
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, 38 Tongyan Road, Tianjin 300350, China
- School of Ecology and Environment, Inner Mongolia University, 235 West College Road, Hohhot 010021, China
| | - Jiubin Chen
- School of Earth System Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Pedro J J Alvarez
- Department of Civil and Environmental Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Wei Chen
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Tong Zhang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, 38 Tongyan Road, Tianjin 300350, China
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3
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Han C, You J, Zhao A, Liao K, Ren H, Hu H. Intermittent polarization: A promising strategy for microbial electricity driven reduction of DOM toxicity in actual industrial wastewater. WATER RESEARCH 2024; 262:122099. [PMID: 39024670 DOI: 10.1016/j.watres.2024.122099] [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: 04/25/2024] [Revised: 07/12/2024] [Accepted: 07/13/2024] [Indexed: 07/20/2024]
Abstract
Dissolved organic matter (DOM) in actual industrial wastewater comprises various compounds that trigger toxicity in aquatic organisms; thus, advanced treatment for reducing DOM toxicity is urgently needed to ensure safe effluent discharge. Herein, we successfully reduced the toxicity of DOM in actual industrial wastewater without external chemical addition by applying intermittent polarization to electrochemical bioreactors. The bioreactor operated under intermittent polarization effectively reduced the toxicity of DOM by 76.7 %, resulting in the toxicity of effluent DOM (determined by malformation rate of zebrafish larvae) reaching less than 3.5 %. Notably, DOM compounds with high double-bond equivalence (DBE ≥ 8) were identified as the key components responsible for the toxicity of DOM through ultrahigh-resolution mass spectrometry analysis. Insight into microbe-DOM interactions revealed that intermittent polarization promoted the microbial consumption of high-DBE components of DOM by both affecting microbial composition (β = -0.5421, p < 0.01) and function (β = -0.4831, p < 0.01), thus regulating effluent DOM toxicity. The study findings demonstrate that intermittent polarization is a promising strategy for microbial electricity-driven reduction of DOM toxicity in actual industrial wastewater to meet the increasing safety requirements of receiving waters.
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Affiliation(s)
- Chenglong Han
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Jiaqian You
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Aixia Zhao
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Kewei Liao
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Haidong Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China.
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4
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Li X, He S, Luo B, Li P, Chen X, Wu M, Song C, Liu C, Yang T, Zhang X, Yang X, Hu J. Engineered Extracellular Vesicles to Enhance Antigen Presentation for Boosting Light-Driven Tumor Immunotherapy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2303541. [PMID: 37608451 DOI: 10.1002/smll.202303541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/26/2023] [Indexed: 08/24/2023]
Abstract
Extracellular vesicles (EVs) have emerged as potential tools for tumor-target therapy accompanied with activating anticancer immune responses by serving as an integrated platform, but usually suffered from the limited cross presentation of tumor-associated antigen by dendritic cells (DCs). Here, a straightforward engineering strategy to construct heat shock proteins 70 (HSP70) highly expressed EVs incapsulated with Te nanoparticles (Te@EVsHSP70 ) for tumor photothermal therapy triggering improved immunotherapy is proposed. Tumor cells are firstly used as bioreactors for intracellular synthesis of Te nanoparticles, and NIR irradiation is subsequently introduced to upregulate the expression of HSP70 to give engineered Te@EVsHSP70 through exocytosis. Te@EVsHSP70 exhibits excellent photothermal performance and enhanced tumor antigen capture capability, which induces significant immunogenic death of tumor cells and improves DCs maturation both in vitro and in vivo. Thus, the engineered EVs demonstrate superior antitumor efficacy through photothermal effect and following provoked antitumor immune responses. This work provides a facile method to fabricate multifunctional EVs-based drug delivery system for improving photothermal-triggered tumor immunotherapy.
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Affiliation(s)
- Xuyu Li
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Shuaicheng He
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Ban Luo
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Department of Ophthalmology, Wenchang People's Hospital, Haikou, 571321, China
| | - Puze Li
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Xue Chen
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Meichan Wu
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Cheng Song
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Chao Liu
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Tian Yang
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Xiaojuan Zhang
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Xiangliang Yang
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
- Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Jun Hu
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
- Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
- Hubei Jiangxia Laboratory, Wuhan, 430200, China
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5
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Wang C, Qiao S. Electron transfer mechanism of intracellular carbon-dependent DNRA inside anammox bacteria. WATER RESEARCH 2023; 244:120443. [PMID: 37572465 DOI: 10.1016/j.watres.2023.120443] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/14/2023]
Abstract
Generally, anaerobic ammonium oxidation (anammox) converts nitrite (NO2-) and ammonium (NH4+) to nitrogen gas (N2) but generates some nitrate (NO3-) (equivalent to 11% of inlet total nitrogen (TN)). Although it reported that anammox bacteria could degrade NO3- via dissimilatory nitrate reduction to ammonium (DNRA) pathway using the intracellular carbon as the electron donor, it is still unclear the specific electron transfer mechanism in this intracellular carbon-dependent DNRA inside anammox bacteria, and whether the sole anammox bacteria could achieve higher TN removal efficiency more than the theoretical maximum of 89%. In this study, transcriptome analysis and metabolic inhibitor experiments demonstrated that NADH generated from the decomposition of the intracellular carbon (glycogen) supplied electrons for the NO3-conversion; the electrons were transferred from NADH to nitrate reductase (Nar) and nitrite reductase forming ammonium (NrfA) from ubiquinone (UQ) and complex III, respectively. Combining the intracellular carbon-dependent DNRA with normal anammox process, an average TN removal efficiency of 95% was achieved by the sole anammox bacteria in a sequencing batch reactor. Fluorescent in situ hybridization (FISH) images and real-time fluorescence quantitative PCR (qPCR) results illustrated anammox bacteria could survive and proliferate in the SBR. Our work improved the understanding of the electron transfer mechanism inside anammox bacteria, and further exploit its potential in nitrogen pollutants removal.
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Affiliation(s)
- Chao Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Sen Qiao
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
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6
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Xia J, Li Y, Jiang X, Chen D, Shen J. Enhanced 4-bromophenol anaerobic biodegradation in electricity-stimulated anaerobic system: The key role of humic acid in reshaping microbial eco-interrelations and functions. JOURNAL OF HAZARDOUS MATERIALS 2023; 453:131426. [PMID: 37084513 DOI: 10.1016/j.jhazmat.2023.131426] [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: 09/14/2022] [Revised: 04/05/2023] [Accepted: 04/14/2023] [Indexed: 05/03/2023]
Abstract
Electricity-stimulated anaerobic system (ESAS) has shown great potential for halogenated organic pollutants removal. Exogenous redox mediators can improve electron transfer efficiency to enhance pollutants removal in ESAS. In this study, humic acid (HA), a low-cost electron mediator, was added into ESAS to enhance the simultaneous reductive debromination and mineralization of 4-bromophenol (4-BP). Results showed that the highest 4-BP removal efficiency at 48 h was 95.43 % with HA dosage of 30 mg/L at - 700 mV, which was 34.67 % higher than that without HA. The addition of HA decreased the requirement for electron donors and enriched Petrimonas and Rhodococcus for humus respiratory. HA addition regulated microbial interactions, and enhanced species cooperation between Petrimonas and dehalogenation species (Thauera and Desulfovibrio), phenol degradation-related species (Rhodococcus) as well as fermentative species (Desulfobulbus). Functional genes related to 4-BP degradation (dhaA/hemE/xylC/chnB/dmpN) and electron transfer (etfB/nuoA/qor/ccoN/coxA) were increased in abundance by HA addition. The enhanced microbial functions, as well as species cooperation and facilitation, all contributed to the improved 4-BP biodegradation in HA-added ESAS. This study provided a deep insight into microbial mechanism driven by HA and offered a promising strategy for improving halogenated organic pollutants removal from wastewater.
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Affiliation(s)
- Jiaohui Xia
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yan Li
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
| | - Xinbai Jiang
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Dan Chen
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Jinyou Shen
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
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7
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Liu Y, Song X, Wang Y, Hou X, Cao X, Wang Y. Manganese-mediated ammonium removal by a bacterial consortium from wastewater: Experimental proof and biochemical mechanisms. BIORESOURCE TECHNOLOGY 2023:129353. [PMID: 37336457 DOI: 10.1016/j.biortech.2023.129353] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/08/2023] [Accepted: 06/16/2023] [Indexed: 06/21/2023]
Abstract
Manganese-redox-mediated nitrogen transformation is promising for ammonium wastewater treatment. However, due to the limited contact between insoluble Mn and the microbe, extracellular electron transfer (EET) inefficiencies become a technical bottleneck in the technical practical application. To overcome this obstacle, humic acid (HA) was introduced to synthesize manganese-humic acid complex (Mn-HA) to increase Mn solubility. The TIN (Total Inorganic Nitrogen) removal rate constant k was 3.18, 1.08, 3.56, 1.13 and 1.05 times higher than CK (Control group) at 10, 15, 20, 40 and 60 mg/L influent nitrate in the MH group, respectively. Mn-HA was inferred to stimulated the nitrogen removal by providing more reaction active sites, bridging Mn-O bonds to transfer electrons and playing a redox role in the respiratory chain. A Mnammox-NDMO (manganese oxide reduction-coupled ammonium oxidation - nitrate/nitrite- dependent manganese oxidation) bacteria consortium was enriched in MH group, containing Mnammox bacteria Geothrix, Geobacter and NDMO bacteria Pseudomonas and Bacillus.
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Affiliation(s)
- Yingying Liu
- College of Environmental Science and Engineering, Donghua University, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Shanghai 201620, China.
| | - Xinshan Song
- College of Environmental Science and Engineering, Donghua University, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Shanghai 201620, China.
| | - Yifei Wang
- College of Environmental Science and Engineering, Donghua University, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Shanghai 201620, China.
| | - Xiaoxiao Hou
- College of Environmental Science and Engineering, Donghua University, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Shanghai 201620, China.
| | - Xin Cao
- College of Environmental Science and Engineering, Donghua University, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Shanghai 201620, China
| | - Yuhui Wang
- College of Environmental Science and Engineering, Donghua University, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Shanghai 201620, China
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8
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Arumugam M, Manikandan DB, Marimuthu SK, Muthusamy G, Kari ZA, Téllez-Isaías G, Ramasamy T. Evaluating Biofilm Inhibitory Potential in Fish Pathogen, Aeromonas hydrophila by Agricultural Waste Extracts and Assessment of Aerolysin Inhibitors Using In Silico Approach. Antibiotics (Basel) 2023; 12:antibiotics12050891. [PMID: 37237796 DOI: 10.3390/antibiotics12050891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/27/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
Aeromonas hydrophila, an opportunistic bacteria, causes several devastating diseases in humans and animals, particularly aquatic species. Antibiotics have been constrained by the rise of antibiotic resistance caused by drug overuse. Therefore, new strategies are required to prevent appropriate antibiotic inability from antibiotic-resistant strains. Aerolysin is essential for A. hydrophila pathogenesis and has been proposed as a potential target for inventing drugs with anti-virulence properties. It is a unique method of disease prevention in fish to block the quorum-sensing mechanism of A. hydrophila. In SEM analysis, the crude solvent extracts of both groundnut shells and black gram pods exhibited a reduction of aerolysin formation and biofilm matrix formation by blocking the QS in A. hydrophila. Morphological changes were identified in the extracts treated bacterial cells. Furthermore, in previous studies, 34 ligands were identified with potential antibacterial metabolites from agricultural wastes, groundnut shells, and black gram pods using a literature survey. Twelve potent metabolites showed interactions between aerolysin and metabolites during molecular docking analysis, in that H-Pyran-4-one-2,3 dihydro-3,5 dihydroxy-6-methyl (-5.3 kcal/mol) and 2-Hexyldecanoic acid (-5.2 kcal/mol) showed promising results with potential hydrogen bond interactions with aerolysin. These metabolites showed a better binding affinity with aerolysin for 100 ns in molecular simulation dynamics. These findings point to a novel strategy for developing drugs using metabolites from agricultural wastes that may be feasible pharmacological solutions for treating A. hydrophila infections for the betterment of aquaculture.
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Affiliation(s)
- Manikandan Arumugam
- Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, India
| | - Dinesh Babu Manikandan
- Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, India
| | - Sathish Kumar Marimuthu
- Department of Pharmaceutical Technology, University College of Engineering, Bharathidasan Institute of Technology (BIT) Campus, Anna University, Tiruchirappalli 620024, India
| | - Govarthanan Muthusamy
- Department of Environmental Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Zulhisyam Abdul Kari
- Department of Agricultural Sciences, Faculty of Agro-Based Industry, Jeli Campus, Universiti Malaysia Kelantan, Jeli 17600, Malaysia
- Advanced Livestock and Aquaculture Research Group, Faculty of Agro-Based Industry, Jeli Campus, Universiti Malaysia Kelantan, Jeli 17600, Malaysia
| | | | - Thirumurugan Ramasamy
- Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, India
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9
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Biocatalysis as a Green Approach for Synthesis of Iron Nanoparticles—Batch and Microflow Process Comparison. Catalysts 2023. [DOI: 10.3390/catal13010112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
There is a growing need for production of iron particles due to their possible use in numerous systems (e.g., electrical, magnetic, catalytic, biological and others). Although severe reaction conditions and heavy solvents are frequently used in production of nanoparticles, green synthesis has arisen as an eco-friendly method that uses biological catalysts. Various precursors are combined with biological material (such as enzymes, herbal extracts, biomass, bacteria or yeasts) that contain chemicals from the main or secondary metabolism that can function as catalysts for production of nanoparticles. In this work, batch (“one-pot”) biosynthesis of iron nanoparticles is reviewed, as well as the possibilities of using microfluidic systems for continuous biosynthesis of iron nanoparticles, which could overcome the limitations of batch synthesis.
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10
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Xu J, Li C, Zhu N, Shen Y, Yuan H. Alleviating the nitrite stress on anaerobic ammonium oxidation by pyrolytic biochar. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 774:145800. [PMID: 33610985 DOI: 10.1016/j.scitotenv.2021.145800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 01/22/2021] [Accepted: 02/07/2021] [Indexed: 06/12/2023]
Abstract
The nitrite (NO2-) inhibition in anaerobic ammonium oxidation (anammox) process is widely reported. Here, the effects of three pyrolytic biochars (CS300, CS550 and CS800) were investigated to alleviate NO2- stress on anammox process under exposure of varied NO2--N concentrations (70, 200, 400 and 600 mg L-1). No nitrite inhibition was observed at 70 mg N L-1. However, the total nitrogen removal efficiency (TNREs) decreased with NO2--N concentration increased, while the biochar-amended groups achieved higher TNREs than the control (CK). At 200 mg N L-1, the TNREs were 60.2%, 99.0%, 98.5% and 86.6% for CK, CS300, CS550 and CS800, respectively. At 400 mg N L-1, the TNREs were 23.3%, 56.0%, 37.1% and 29.7% for CK, CS300, CS550 and CS800, respectively. At 600 mg N L-1 in which severe inhibition was observed, the TNREs were increased by 231% (p = 0.002), 149% (p = 0.014), and 51.0% (p = 0.166) for CS300, CS550 and CS800, respectively, as compared to CK, with the corresponding specific anammox activity increased by 3.1-, 2,0- and 1.1-folds, respectively. CS300 enriched the relative abundance of Candidatus Kuenenia and increased the gene copies of functional genes (hzsA, hdh, nirS and nirK). Besides, CS300 effectively alleviated the suppression of three membrane-associated enzyme complexes for anammox electron transport chain, indicating the possible contribution of redox-active moieties of CS300 to energy conversion metabolism for mitigating the NO2--N inhibition. This study provided an effective strategy for alleviating NO2--N stress by applying an environmentally compatible material (biochar) on anammox process.
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Affiliation(s)
- Jiajia Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Chao Li
- Hunan BISEN Environmental & Energy Co. Ltd., Changsha 410100, China
| | - Nanwen Zhu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China; Shanghai Institute of Pollution Control and Ecological Security, 1239 Siping Road, Shanghai 200092, China
| | - Yanwen Shen
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China; Hunan BISEN Environmental & Energy Co. Ltd., Changsha 410100, China.
| | - Haiping Yuan
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
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Cui D, Zhang M, Wang J, Wang H, Zhao M. Effect of quinoid redox mediators during azo dye decolorization by anaerobic sludge: Considering the catalyzing mechanism and the methane production. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 202:110859. [PMID: 32574861 DOI: 10.1016/j.ecoenv.2020.110859] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 06/01/2020] [Accepted: 06/03/2020] [Indexed: 06/11/2023]
Abstract
The effects of quinoid compounds on azo dyes decolorization were studied. Compared with other quinones, menadione was the most effective at aiding azo dye decolorization. Sodium formate was a suitable carbon source for the anaerobic decolorization system. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis indicated that the microbial structure changed in response to varying carbon sources. Phylogenetic analysis showed that the anaerobic sludge was consisted mainly of nine genera. The mechanism studies showed that the biotransformation of menadione to its hydroquinone form was the rate-limiting step in the dye decolorization process. Moreover, study of the electron transfer mechanism of quinone-mediated reduction showed that azo dye decolorization is not a specific reaction. The NADH chain was involved in the decolorization process. The methane production test indicated that azo dyes had an inhibitory effect on methane production. However, supplementation with a redox mediator could recover the inhibited methanogenesis. High-throughput sequencing analysis revealed that the methanogenic archaeal community was altered in the anaerobic sludge with or without azo dyes and the redox mediator.
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Affiliation(s)
- Daizong Cui
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Miao Zhang
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Jianqi Wang
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - He Wang
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Min Zhao
- College of Life Science, Northeast Forestry University, Harbin, 150040, China.
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12
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Liu L, Liu G, Zhou J, Wang J, Jin R. Cotransport of biochar and Shewanella oneidensis MR-1 in saturated porous media: Impacts of electrostatic interaction, extracellular electron transfer and microbial taxis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 658:95-104. [PMID: 30572219 DOI: 10.1016/j.scitotenv.2018.12.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 11/17/2018] [Accepted: 12/04/2018] [Indexed: 06/09/2023]
Abstract
Biochar widely applied to soil can influence microbial community composition and participate in extracellular electron transfer (EET). However, little is known about the cotransport behaviors of bacteria and biochar in aquifer and soil-water environments, which can affect the fate and application performance of biochar. In this study, we found that in comparison to their individual transport behaviors, the mobilities of cotransporting Shewanella oneidensis MR-1 and biochar colloid (BC) were significantly inhibited. The decreasing colloidal mobilities at higher ionic strengths signified the importance of electrostatic interaction between cell and BC in cotransport. Moreover, the less suppressed cotransport of BC and mutants defective of EET and the elevated inhibition effects on cotransport by adding exogenous electron donor suggested the importance of EET. Difference in cotransport behavior was also observed with BC having different redox states. Compared with oxidized BC, reduced BC with higher hydrophobicity led to easier aggregation with cell and higher retention in column. More importantly, MR-1 exhibited EET-dependent taxis towards biochar, which also contributed to the enhanced heteroaggregation and decreased mobilities of cell and biochar. Our results highlight that metabolic activities of microbes towards abiotic colloids cannot be neglected when assessing their transport behaviors, especially in subsurface environments abounded with redox-active inorganic particles and microbes performing extracellular respiration.
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Affiliation(s)
- Lecheng Liu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Guangfei Liu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
| | - Jiti Zhou
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Jing Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Ruofei Jin
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
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13
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Kooli WM, Junier T, Shakya M, Monachon M, Davenport KW, Vaideeswaran K, Vernudachi A, Marozau I, Monrouzeau T, Gleasner CD, McMurry K, Lienhard R, Rufener L, Perret JL, Sereda O, Chain PS, Joseph E, Junier P. Remedial Treatment of Corroded Iron Objects by Environmental Aeromonas Isolates. Appl Environ Microbiol 2019; 85:e02042-18. [PMID: 30478230 PMCID: PMC6344634 DOI: 10.1128/aem.02042-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 11/07/2018] [Indexed: 11/20/2022] Open
Abstract
Using bacteria to transform reactive corrosion products into stable compounds represents an alternative to traditional methods employed in iron conservation. Two environmental Aeromonas strains (CA23 and CU5) were used to transform ferric iron corrosion products (goethite and lepidocrocite) into stable ferrous iron-bearing minerals (vivianite and siderite). A genomic and transcriptomic approach was used to analyze the metabolic traits of these strains and to evaluate their pathogenic potential. Although genes involved in solid-phase iron reduction were identified, key genes present in other environmental iron-reducing species are missing from the genome of CU5. Several pathogenicity factors were identified in the genomes of both strains, but none of these was expressed under iron reduction conditions. Additional in vivo tests showed hemolytic and cytotoxic activities for strain CA23 but not for strain CU5. Both strains were easily inactivated using ethanol and heat. Nonetheless, given a lesser potential for a pathogenic lifestyle, CU5 is the most promising candidate for the development of a bio-based iron conservation method stabilizing iron corrosion. Based on all the results, a prototype treatment was established using archaeological items. On those, the conversion of reactive corrosion products and the formation of a homogenous layer of biogenic iron minerals were achieved. This study shows how naturally occurring microorganisms and their metabolic capabilities can be used to develop bio-inspired solutions to the problem of metal corrosion.IMPORTANCE Microbiology can greatly help in the quest for a sustainable solution to the problem of iron corrosion, which causes important economic losses in a wide range of fields, including the protection of cultural heritage and building materials. Using bacteria to transform reactive and unstable corrosion products into more-stable compounds represents a promising approach. The overall aim of this study was to develop a method for the conservation and restoration of corroded iron items, starting from the isolation of iron-reducing bacteria from natural environments. This resulted in the identification of a suitable candidate (Aeromonas sp. strain CU5) that mediates the formation of desirable minerals at the surfaces of the objects. This led to the proof of concept of an application method on real objects.
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Affiliation(s)
- Wafa M Kooli
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Laboratory of Technologies for Heritage Materials, Institute of Chemistry, University of Neuchâtel, Neuchâtel, Switzerland
| | - Thomas Junier
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Migun Shakya
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Mathilde Monachon
- Laboratory of Technologies for Heritage Materials, Institute of Chemistry, University of Neuchâtel, Neuchâtel, Switzerland
| | - Karen W Davenport
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | | | | | - Ivan Marozau
- Centre Suisse d'Electronique et de Microtechnique, Neuchâtel, Switzerland
| | - Teddy Monrouzeau
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Cheryl D Gleasner
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Kim McMurry
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | | | | | | | - Olha Sereda
- Centre Suisse d'Electronique et de Microtechnique, Neuchâtel, Switzerland
| | - Patrick S Chain
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Edith Joseph
- Laboratory of Technologies for Heritage Materials, Institute of Chemistry, University of Neuchâtel, Neuchâtel, Switzerland
- Haute Ecole Arc Conservation-Restauration, Haute École Spécialisée de Suisse Occidentale, Neuchâtel, Switzerland
| | - Pilar Junier
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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Yu L, Yuan Y, Rensing C, Zhou S. Combined spectroelectrochemical and proteomic characterizations of bidirectional Alcaligenes faecalis-electrode electron transfer. Biosens Bioelectron 2018; 106:21-28. [DOI: 10.1016/j.bios.2018.01.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 01/09/2018] [Accepted: 01/13/2018] [Indexed: 10/18/2022]
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15
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He H, Huang B, Fu G, Du Y, Xiong D, Lai C, Pan X. Coupling electrochemical and biological methods for 17α-ethinylestradiol removal from water by different microorganisms. JOURNAL OF HAZARDOUS MATERIALS 2017; 340:120-129. [PMID: 28715735 DOI: 10.1016/j.jhazmat.2017.06.070] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 06/03/2017] [Accepted: 06/28/2017] [Indexed: 06/07/2023]
Abstract
17α-ethynylestradiol (EE2) has become a growing concern due to its wide detection and high estrogenic potency. However, biodegradation of EE2 with individual microorganisms demonstrated poor degradation efficiency ranging from 10.3% to 45.8% in 120h. Now, a system combining electrochemical with biological degradation was tested for its ability to remove EE2 from aqueous solution. EE2 removal is promoted at high dissolved oxygen concentrations and low pH when electrochemical methods alone are employed. Coupling electrochemical methods with anaerobic bacteria can improve the EE2 removal after 90min to as much as 81.9% with a reaction rate constant of 0.0195min-1. An electric current of 100mA at pH5.5 inhibits the growth of most microbial species, but Shewanella and Aeromonas survive well. They can enhance the efficiency of direct electron transfer efficiency between the bacteria and the electrodes, promoting EE2 degradation. This study provided a theoretical basis for the future applicability of bioelectrochemical technology to remove steroids from waste water.
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Affiliation(s)
- Huan He
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Bin Huang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
| | - Gen Fu
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Yanan Du
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Dan Xiong
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Chaochao Lai
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Xuejun Pan
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
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16
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Zhang C, Guo J, Lian J, Lu C, Ngo HH, Guo W, Song Y, Guo Y. Characteristics of electron transport chain and affecting factors for thiosulfate-driven perchlorate reduction. CHEMOSPHERE 2017; 185:539-547. [PMID: 28719873 DOI: 10.1016/j.chemosphere.2017.07.039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 06/28/2017] [Accepted: 07/09/2017] [Indexed: 06/07/2023]
Abstract
The mechanism for perchlorate reduction was investigated using thiosulfate-driven (T-driven) perchlorate reduction bacteria. The influences of various environmental conditions on perchlorate reduction, including pH, temperature and electron acceptors were examined. The maximum perchlorate removal rate was observed at pH 7.5 and 40 °C. Perchlorate reduction was delayed due to the coexistence of perchlorate-chlorate and perchlorate-nitrate. The mechanism of the T-driven perchlorate reduction electron transport chain (ETC) was also investigated by utilizing different inhibitors. The results were as follows: firstly, the NADH dehydrogenase was not involved in the ETC; secondly, the FAD dehydrogenase and quinone loop participated in the ETC; and thirdly, cytochrome oxidase was the main pathway in the ETC. Meanwhile, microbial consortium structure analysis indicated that Sulfurovum which can oxidize sulfur compounds coupled to the reduction of nitrate or perchlorate was the primary bacterium in the T-driven and sulfur-driven consortium. This study generates a better understanding of the mechanism of T-driven perchlorate reduction.
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Affiliation(s)
- Chao Zhang
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26#, Tianjin 300384, PR China; School of Environmental Science and Engineering & Pollution Prevention Biotechnology Laboratory of Hebei Province, Hebei University of Science and Technology, Yuhua East Road 70#, Shijiazhuang 050018, PR China
| | - Jianbo Guo
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26#, Tianjin 300384, PR China; School of Environmental Science and Engineering & Pollution Prevention Biotechnology Laboratory of Hebei Province, Hebei University of Science and Technology, Yuhua East Road 70#, Shijiazhuang 050018, PR China.
| | - Jing Lian
- School of Environmental Science and Engineering & Pollution Prevention Biotechnology Laboratory of Hebei Province, Hebei University of Science and Technology, Yuhua East Road 70#, Shijiazhuang 050018, PR China
| | - Caicai Lu
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26#, Tianjin 300384, PR China
| | - Huu Hao Ngo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Wenshan Guo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Yuanyuan Song
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26#, Tianjin 300384, PR China
| | - Yankai Guo
- School of Environmental Science and Engineering & Pollution Prevention Biotechnology Laboratory of Hebei Province, Hebei University of Science and Technology, Yuhua East Road 70#, Shijiazhuang 050018, PR China
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17
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Liu YN, Zhang F, Li J, Li DB, Liu DF, Li WW, Yu HQ. Exclusive Extracellular Bioreduction of Methyl Orange by Azo Reductase-Free Geobacter sulfurreducens. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:8616-8623. [PMID: 28671824 DOI: 10.1021/acs.est.7b02122] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Azo dyes are a class of recalcitrant organic pollutants causing severe environmental pollution. For their biodecolorization, the azo reductase system was considered as the major molecular basis in bacteria. However, the intracellular localization of azo reductase limits their function for efficient azo dye decolorization. This limitation may be circumvented by electrochemically active bacteria (EAB) which is capable of extracellular respiration. To verify the essential role of extracellular respiration in azo dye decolorization, Geobacter sulfurreducens PCA, a model EAB, was used for the bioreduction of methyl orange (MO), a typical azo dye. G. sulfurreducens PCA efficiently reduced MO into amines. Kinetic results showed that G. sulfurreducens PCA had the highest decolorization efficiency among the currently known MO reducing bacteria. Electrons from acetate oxidization by this strain were transferred by the respiratory chain to MO. The mass and electron balances, fluorescent probing and proteinase K treatment experimental results indicate that the biodecolorization of MO by G. sulfurreducens PCA is an exclusive extracellular process. OmcB, OmcC and OmcE were identified as the key outer-membrane proteins for the extracellular MO reduction. This work deepens our understanding of EAB physiology and is useful for the decontamination of environments polluted with azo dyes. The contribution of extracellular respiration to pollutants reduction will broaden the environmental applications of EAB.
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Affiliation(s)
- Yi-Nan Liu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China , Hefei, 230026, China
| | - Feng Zhang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China , Hefei, 230026, China
| | - Jie Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China , Hefei, 230026, China
| | - Dao-Bo Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China , Hefei, 230026, China
| | - Dong-Feng Liu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China , Hefei, 230026, China
| | - Wen-Wei Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China , Hefei, 230026, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China , Hefei, 230026, China
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18
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Wang S, Guo J, Lian J, Ngo HH, Guo W, Liu Y, Song Y. Rapid start-up of the anammox process by denitrifying granular sludge and the mechanism of the anammox electron transport chain. Biochem Eng J 2016. [DOI: 10.1016/j.bej.2016.09.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Su YB, Chang WC, Hsi HC, Lin CC. Investigation of biogeochemical controls on the formation, uptake and accumulation of methylmercury in rice paddies in the vicinity of a coal-fired power plant and a municipal solid waste incinerator in Taiwan. CHEMOSPHERE 2016; 154:375-384. [PMID: 27070857 DOI: 10.1016/j.chemosphere.2016.03.087] [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: 12/29/2015] [Revised: 03/05/2016] [Accepted: 03/19/2016] [Indexed: 06/05/2023]
Abstract
Recent studies have shown that rice consumption is another critical route of human exposure to methylmercury (MeHg), the most toxic and accumulative form of mercury (Hg) in the food web. Yet, the mechanisms that underlie the production and accumulation of MeHg in the paddy ecosystem are still poorly understood. In 2013 and 2014, we conducted field campaigns and laboratory experiments over a rice growing season to examine Hg and MeHg cycling, as well as associated biogeochemistry in a suite of paddies close to a municipal solid waste incinerator and a coal-fired power plant station in Taiwan. Concentrations of total Hg and MeHg in paddy soil and rice grain at both sites were low and found not to exceed the control standards for farmland soil and edible rice in Taiwan. However, seasonal variations of MeHg concentrations observed in pore water samples indicate that the in situ bioavailability of inorganic Hg and activity of Hg-methylating microbes in the rhizosphere increased from the early-season and peaked at the mid-season, presumably due to the anoxia created under flooded conditions and root exudation of organic compounds. The presence of Hg-methylators was also confirmed by the hgcA gene detected in all root soil samples. Subsequent methylation tests performed by incubating the root soil with inorganic Hg and an inhibitor or stimulant specific for certain microbes further revealed that sulfate-reducers might have been the principal Hg-methylting guild at the study sites. Interestingly, results of hydroponic experiments conducted by cultivating rice in a defined nutrient solution amended with fixed MeHg and varying levels of MeHg-binding ligands suggested that chemical speciation in soil pore water may play a key role in controlling MeHg accumulation in rice, and both passive and active transport pathways seem to take place in the uptake of MeHg in rice roots.
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Affiliation(s)
- Yen-Bin Su
- Graduate Institute of Environmental Engineering, National Central University, Taoyuan 32001, Taiwan, ROC
| | - Wei-Chun Chang
- Graduate Institute of Environmental Engineering, National Central University, Taoyuan 32001, Taiwan, ROC
| | - Hsing-Cheng Hsi
- Institute of Environmental Engineering and Management, National Taipei University of Technology, Taipei 10608, Taiwan, ROC; Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 10617, Taiwan, ROC
| | - Chu-Ching Lin
- Graduate Institute of Environmental Engineering, National Central University, Taoyuan 32001, Taiwan, ROC.
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20
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Rajendran K, Sen S. Optimization of process parameters for the rapid biosynthesis of hematite nanoparticles. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2016; 159:82-7. [DOI: 10.1016/j.jphotobiol.2016.03.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Revised: 03/07/2016] [Accepted: 03/14/2016] [Indexed: 10/22/2022]
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21
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Ma C, Yu Z, Lu Q, Zhuang L, Zhou SG. Anaerobic humus and Fe(III) reduction and electron transport pathway by a novel humus-reducing bacterium, Thauera humireducens SgZ-1. Appl Microbiol Biotechnol 2014; 99:3619-28. [PMID: 25503315 DOI: 10.1007/s00253-014-6254-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 11/18/2014] [Indexed: 11/30/2022]
Abstract
In this study, an anaerobic batch experiment was conducted to investigate the humus- and Fe(III)-reducing ability of a novel humus-reducing bacterium, Thauera humireducens SgZ-1. Inhibition tests were also performed to explore the electron transport pathways with various electron acceptors. The results indicate that in anaerobic conditions, strain SgZ-1 possesses the ability to reduce a humus analog, humic acids, soluble Fe(III), and Fe(III) oxides. Acetate, propionate, lactate, and pyruvate were suitable electron donors for humus and Fe(III) reduction by strain SgZ-1, while fermentable sugars (glucose and sucrose) were not. UV-visible spectra obtained from intact cells of strain SgZ-1 showed absorption peaks at 420, 522, and 553 nm, characteristic of c-type cytochromes (cyt c). Dithionite-reduced cyt c was reoxidized by Fe-EDTA and HFO (hydrous ferric oxide), which suggests that cyt c within intact cells of strain SgZ-1 has the ability to donate electrons to extracellular Fe(III) species. Inhibition tests revealed that dehydrogenases, quinones, and cytochromes b/c (cyt b/c) were involved in reduction of AQS (9, 10-anthraquinone-2-sulfonic acid, humus analog) and oxygen. In contrast, only NADH dehydrogenase was linked to electron transport to HFO, while dehydrogenases and cyt b/c were found to participate in the reduction of Fe-EDTA. Thus, various different electron transport pathways are employed by strain SgZ-1 for different electron acceptors. The results from this study help in understanding the electron transport processes and environmental responses of the genus Thauera.
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Affiliation(s)
- Chen Ma
- Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, 510650, People's Republic of China
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22
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Xi Z, Guo J, Lian J, Li H, Zhao L, Liu X, Zhang C, Yang J. Study the catalyzing mechanism of dissolved redox mediators on bio-denitrification by metabolic inhibitors. BIORESOURCE TECHNOLOGY 2013; 140:22-27. [PMID: 23669099 DOI: 10.1016/j.biortech.2013.04.065] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2013] [Revised: 04/15/2013] [Accepted: 04/16/2013] [Indexed: 06/02/2023]
Abstract
The effect of dissolved redox mediators on denitrification by Paracoccus versutus sp. GW1 were studied with α-AQS, AQS, 1,5-AQDS, AQDS and 2,7-AQDS. AQDS presented the best catalytic effect which increased denitrification rate by 1.5-fold with 0.17 mmol L(-1). Denitrification rate was found to be pseudo-zero order with 0-0.32 mmol L(-1) AQDS (k=19.874C AQDS+10.301 (R(2)=0.9984)). The accelerating mechanism for respiratory chain was also explored by using metabolic inhibitors. Addition of AQDS eased the inhibitions of rotenone, dicumarol, sodium azide on respiratory chain, and enhanced the nitrite accumulation during bio-denitrification process. AQDS exhibited slight catalytic effect on nitrite denitrification. These results allowed us to deduce the accelerating site of AQDS on the denitrification respiratory chain. Increased nitrate denitrification by AQDS might mainly attribute to the accelerated electrons transfer from NADH to nitrate reductase via complex I and ubiquinone/ubiqunol. This study provided further understanding of the mechanism of redox mediators on denitrification.
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Affiliation(s)
- Zhenhua Xi
- School of Environmental Science and Engineering, Hebei University of Science and Technology, Yuhua East Road 70#, Shijiazhuang City 050018, PR China
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Stimulatory effect of xenobiotics on oxidative electron transport of chemolithotrophic nitrifying bacteria used as biosensing element. PLoS One 2013; 8:e53484. [PMID: 23326438 PMCID: PMC3541135 DOI: 10.1371/journal.pone.0053484] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 11/30/2012] [Indexed: 02/01/2023] Open
Abstract
Electron transport chain (ETCh) of ammonium (AOB) and nitrite oxidizing bacteria (NOB) participates in oxidation of ammonium to nitrate (nitrification). Operation of ETCh may be perturbed by a range of water-soluble xenobiotics. Therefore, consortia of nitrifying bacteria may be used as a biosensor to detect water contamination. A surprising feature of this system is an increase of oxygen consumption, detected in the presence of certain inhibitors of ETCh. Thus, to shed light on the mechanism of this effect (and other differences between inhibitors) we monitored separately respiration of the bacteria of the first (AOB - Nitrosomonas) and second (NOB -Nitrobacter) stages of nitrification. Furthermore, we measured plasma membrane potential and the level of reduction of NAD(P)H. We propose a novel model of ETCh in NOB to explain the role of reverse electron transport in the stimulation of oxygen consumption (previously attributed to hormesis).
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24
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Yu RQ, Flanders JR, Mack EE, Turner R, Mirza MB, Barkay T. Contribution of coexisting sulfate and iron reducing bacteria to methylmercury production in freshwater river sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:2684-91. [PMID: 22148328 DOI: 10.1021/es2033718] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We investigated microbial methylmercury (CH(3)Hg) production in sediments from the South River (SR), VA, an ecosystem contaminated with industrial mercury (Hg). Potential Hg methylation rates in samples collected at nine sites were low in late spring and significantly higher in late summer. Demethylation of (14)CH(3)Hg was dominated by (14)CH(4) production in spring, but switched to producing mostly (14)CO(2) in the summer. Fine-grained sediments originating from the erosion of river banks had the highest CH(3)Hg concentrations and were potential hot spots for both methylation and demethylation activities. Sequencing of 16S rRNA genes of cDNA recovered from sediment RNA extracts indicated that at least three groups of sulfate-reducing bacteria (SRB) and one group of iron-reducing bacteria (IRB), potential Hg methylators, were active in SR sediments. SRB were confirmed as a methylating guild by amendment experiments showing significant sulfate stimulation and molybdate inhibition of methylation in SR sediments. The addition of low levels of amorphous iron(III) oxyhydroxide significantly stimulated methylation rates, suggesting a role for IRB in CH(3)Hg synthesis. Overall, our studies suggest that coexisting SRB and IRB populations in river sediments contribute to Hg methylation, possibly by temporally and spatially separated processes.
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Affiliation(s)
- Ri-Qing Yu
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey 08901, United States.
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Xu M, Guo J, Kong X, Chen X, Sun G. Fe(III)-enhanced Azo Reduction by Shewanella decolorationis S12. Appl Microbiol Biotechnol 2007; 74:1342-9. [PMID: 17216448 DOI: 10.1007/s00253-006-0773-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Revised: 11/16/2006] [Accepted: 11/17/2006] [Indexed: 10/23/2022]
Abstract
Shewanella decolorationis S12 is capable of high rates of azo dye decolorization and dissimilatory Fe(III) reduction. Under anaerobic conditions, when Fe(III) and azo dye were copresent in S12 cultures, dissimilatory Fe(III) reduction and azo dye biodecolorization occurred simultaneously. Furthermore, the dye decolorization was enhanced by the presence of Fe(III). When 1 mM Fe(III) was added, the methyl red decolorizing efficiency was 72.1% after cultivation for 3 h, whereas the decolorizing efficiency was only 60.5% in Fe(III)-free medium. The decolorizing efficiencies increased as the concentration of Fe(III) was increased from 0 to 6 mM. Enzyme activities, which mediate the dye decolorization and Fe(III) reduction, were not affected by preadaption of cells to Fe(III) and azo dye nor by the addition of chloramphenicol. Both the Fe(III) reductase and the azo reductase were membrane associated. The respiratory electron transport chain inhibitors metyrapone, dicumarol, and stigmatellin showed significantly different effects on Fe(III) reduction than on azo dye decolorization.
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Affiliation(s)
- Meiying Xu
- Guangdong Institute of Microbiology, 100 Central Xianlie Road, Guangzhou 510070, People's Republic of China
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Turi JL, Wang X, McKie AT, Nozik-Grayck E, Mamo LB, Crissman K, Piantadosi CA, Ghio AJ. Duodenal cytochrome b: a novel ferrireductase in airway epithelial cells. Am J Physiol Lung Cell Mol Physiol 2006; 291:L272-80. [PMID: 16510471 DOI: 10.1152/ajplung.00342.2005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Catalytically active iron in the lung causes oxidative stress and promotes microbial growth that can be limited by intracellular sequestration of iron within ferritin. Because cellular iron uptake requires membrane ferrireductase activity that in the gut can be provided by duodenal cytochrome b (Dcytb), we sought Dcytb in the lung to test the hypothesis that it contributes to epithelial iron regulation by reducing Fe3+ for cellular iron transport. Dcytb expression was found in respiratory epithelium in vitro and in vivo and was responsive to iron concentration. Iron transport was measured in human bronchial epithelial (HBE) cells using inductively coupled plasma atomic emission spectroscopy and was demonstrated to be partially inhibited in the presence of Dcytb-blocking antibody, suggesting that Dcytb reduces Fe3+ for cellular iron transport. A definite source of reducing equivalents for Dcytb was sought but not identified. We found no evidence that ascorbate was involved but did demonstrate that O2−· production decreased when Dcytb function was blocked. The presence of Dcytb in airway epithelial cells and its regulation by iron therefore may contribute to pulmonary cytoprotection.
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Affiliation(s)
- Jennifer L Turi
- Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA.
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