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Long M, Zhu J, Wang X, Hu S, Zhang J, Cheng K, Liu T, Liu W, Reinfelder JR, Wu Y, Li F. Hematite enhances microbial autotrophic nitrate removal in carbonate and phosphate-rich environments by increasing Fe(II) activity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175002. [PMID: 39053529 DOI: 10.1016/j.scitotenv.2024.175002] [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: 02/26/2024] [Revised: 07/01/2024] [Accepted: 07/22/2024] [Indexed: 07/27/2024]
Abstract
Groundwater contamination by nitrates presents significant risks to both human health and the environment. In groundwater characterized as oligotrophic-low in organic carbon, but abundant in carbonate and phosphate-chemolithoautotrophic bacteria, including nitrate-reducing Fe(II)-oxidizing bacteria (NRFeOB), play a vital role in denitrification. The chemoautotrophic nitrate reduction is sensitive to environmental factors, including widespread iron oxides like hematite in nature. However, the specific mechanisms of this influence remain unclear. We examined the mechanism of how hematite impacts autotrophic nitrate reduction in a model NRFeOB community known as culture KS. We found that hematite enhances the rate of autotrophic nitrate reduction by promoting Fe(II) oxidation. Mössbauer spectroscopy detected a significant amount of adsorbed Fe(II) when hematite was present, leading to a reduction in dissolved ferrous iron. In conjunction with XRD data, it can be inferred that the formation of vivianite decreased, thereby increasing the Fe(II) activity in the reaction system. Within the culture KS bacterial consortium, hematite fosters the proliferation of autotrophic microorganisms, specifically Gallionellaceae, and amplifies the presence of denitrifying microbes, notably Rhodanobacter. This dual enhancement improves Fe(II) utilization and nitrate reduction capabilities. Our findings highlight intricate interactions between hematite and a model NRFeOB community, offering insights into groundwater nitrate removal mechanisms and the ecological strategies of autotrophic bacteria in mineral-rich environments.
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Affiliation(s)
- Mingliang Long
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou 510650, China
| | - Jiaxi Zhu
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou 510650, China
| | - Xinxin Wang
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou 510650, China
| | - Shiwen Hu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou 510650, China
| | - Juntao Zhang
- Guangzhou Institute of Forestry and Landscape Architecture, 428 Guangyuan Middle Road, Guangzhou 510405, China
| | - Kuan Cheng
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou 510650, China
| | - Tongxu Liu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou 510650, China
| | - Wei Liu
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China.
| | - John R Reinfelder
- Department of Environmental Sciences, Rutgers University, New Brunswick, NJ 08901, United States
| | - Yundang Wu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou 510650, China.
| | - Fangbai Li
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, 808 Tianyuan Road, Guangzhou 510650, China
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2
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Liu JB, Zhang H, Wang H, He B, Wang H, Jin R, Tian T. Remediation of arsenic- and nitrate-contaminated groundwater through iron-dependent autotrophic denitrifying culture. ENVIRONMENTAL RESEARCH 2024; 257:119239. [PMID: 38810825 DOI: 10.1016/j.envres.2024.119239] [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: 02/23/2024] [Revised: 05/11/2024] [Accepted: 05/26/2024] [Indexed: 05/31/2024]
Abstract
Groundwater contamination with arsenic and nitrate poses a pressing concern for the safety of local communities. Bioremediation, utilizing Fe(II)-oxidizing nitrate reducing bacteria, shows promise as a solution to this problem. However, the relatively weak environmental adaptability of a single bacterium hampers practical application. Therefore, this study explored the feasibility and characteristics of a mixed iron-dependent autotrophic denitrifying (IDAD) culture for effectively removing arsenic and nitrate from synthetic groundwater. The IDAD biosystem exhibited stable performace and arsenic resistance, even at a high As(III) concentration of 800 μg/L. Although the nitrogen removal efficiency of the IDAD biosystem decreased from 71.4% to 64.7% in this case, the arsenic concentration in the effluent remained below the standard (10 μg/L) set by WHO. The crystallinity of the lepidocrocite produced by the IDAD culture decreased with increasing arsenic concentration, but the relative abundance of the key iron-oxidizing bacteria norank_f_Gallionellaceae in the culture showed an opposite trend. Metagenomic analysis revealed that the IDAD culture possess arsenic detoxification pathways, including redox, methylation, and efflux of arsenic, which enable it to mitigate the adverse impact of arsenic stress. This study provides theoretical understanding and technical support for the remediation of arsenic and nitrate-contaminated groundwater using the IDAD culture.
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Affiliation(s)
- Jia-Bo Liu
- 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
| | - Hongbin Zhang
- 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
| | - Hefei Wang
- National Marine Environmental Monitoring Center, Dalian, 116023, China.
| | - Banghui He
- 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
| | - Huixuan 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
| | - Ruofei Jin
- 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
| | - Tian Tian
- 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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3
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Zheng L, Wu H, Ding A, Tan Q, Wang X, Xing Y, Tian Q, Zhang Y. Optimization of operating parameters and microbiological mechanism of a low C/N wastewater treatment system dominated by iron-dependent autotrophic denitrification. ENVIRONMENTAL RESEARCH 2024; 250:118419. [PMID: 38316389 DOI: 10.1016/j.envres.2024.118419] [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: 11/05/2023] [Revised: 01/26/2024] [Accepted: 02/02/2024] [Indexed: 02/07/2024]
Abstract
Ferrous iron (Fe2+) reduces the amount of external carbon source used for the denitrification of low-C/N wastewater. The effects of key operating parameters on the efficiency of ferrous-dependent autotrophic denitrification (FDAD) and the functioning mechanism of the microbiome can provide a regulatory strategy for improving the denitrification efficiency of low C/N wastewater. In this study, the response surface method (RSM) was used to explore the influence of four important parameters-the molar ratio of Fe2+ to NO3--N (Fe/N), total organic carbon (TOC), the molar ratio of inorganic carbon to NO3--N (IC/N) and sludge volume (SV, %)-on the FDAD efficiency. Functional prediction and molecular ecological networks based on high-throughputs sequencing techniques were used to explore changes in the structure, function, and biomarkers of the sludge microbial community. The results showed that Fe/N and TOC were the main parameters affecting FDAD efficiency. Higher concentrations of TOC and high Fe/N ratios provided more electron donors and improved denitrification efficiency, but weakened the importance of biomarkers (Rhodanobacter, Thermomonas, Comamonas, Thauera, Geothrix and unclassified genus of family Gallionellaceae) in the sludge ecological network. When Fe/N > 4, the denitrification efficiency fluctuated significantly. Functional prediction results indicated that genes that dominated N2O and NO reduction and the genes that dominated Fe2+ transport showed a slight decrease in abundance at high Fe/N levels. In light of these findings, we recommend the following optimization ranges of parameters: Fe/N (3.5-4); TOC/N (0.36-0.42); IC/N (3.5-4); and SV (approximately 35%).
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Affiliation(s)
- Lei Zheng
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Haoming Wu
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Aizhong Ding
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing, 100875, China.
| | - Qiuyang Tan
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Xue Wang
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Yuzi Xing
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Qi Tian
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Yaoxin Zhang
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
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4
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Visser AN, Martin JD, Osenbrück K, Rügner H, Grathwohl P, Kappler A. In situ incubation of iron(II)-bearing minerals and Fe(0) reveals insights into metabolic flexibility of chemolithotrophic bacteria in a nitrate polluted karst aquifer. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:172062. [PMID: 38554974 DOI: 10.1016/j.scitotenv.2024.172062] [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: 12/04/2023] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 04/02/2024]
Abstract
Groundwater nitrate pollution is a major reason for deteriorating water quality and threatens human and animal health. Yet, mitigating groundwater contamination naturally is often complicated since most aquifers are limited in bioavailable carbon. Since metabolically flexible microbes might have advantages for survival, this study presents a detailed description and first results on our modification of the BacTrap© method, aiming to determine the prevailing microbial community's potential to utilize chemolithotrophic pathways. Our microbial trapping devices (MTDs) were amended with four different iron sources and incubated in seven groundwater monitoring wells for ∼3 months to promote growth of nitrate-reducing Fe(II)-oxidizing bacteria (NRFeOxB) in a nitrate-contaminated karst aquifer. Phylogenetic analysis based on 16S rRNA gene sequences implies that the identity of the iron source influenced the microbial community's composition. In addition, high throughput amplicon sequencing revealed increased relative 16S rRNA gene abundances of OTUs affiliated to genera such as Thiobacillus, Rhodobacter, Pseudomonas, Albidiferax, and Sideroxydans. MTD-derived enrichments set up with Fe(II)/nitrate/acetate to isolate potential NRFeOxB, were dominated by e.g., Acidovorax spp., Paracoccus spp. and Propionivibrio spp. MTDs are a cost-effective approach for investigating microorganisms in groundwater and our data not only solidifies the MTD's capacity to provide insights into the metabolic flexibility of the aquifer's microbial community, but also substantiates its metabolic potential for anaerobic Fe(II) oxidation.
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Affiliation(s)
- Anna-Neva Visser
- GeoZentrum Nordbayern, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany; Department of Geosciences, University of Tübingen, Germany.
| | - Joseph D Martin
- Department of Biology, Terrestrial Ecology, University of Copenhagen, Denmark
| | - Karsten Osenbrück
- Department of Geosciences, University of Tübingen, Germany; Federal Institute for Geosciences and Natural Resources (BGR), Hannover, Germany
| | - Hermann Rügner
- Department of Geosciences, University of Tübingen, Germany
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5
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Zhang HB, Wang HF, Liu JB, Bi Z, Jin RF, Tian T. Anaerobic ammonium oxidation coupled to iron(III) reduction catalyzed by a lithoautotrophic nitrate-reducing iron(II) oxidizing enrichment culture. THE ISME JOURNAL 2024; 18:wrae149. [PMID: 39083023 PMCID: PMC11366258 DOI: 10.1093/ismejo/wrae149] [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: 02/20/2024] [Revised: 07/16/2024] [Accepted: 07/30/2024] [Indexed: 09/03/2024]
Abstract
The last two decades have seen nitrogen/iron-transforming bacteria at the forefront of new biogeochemical discoveries, such as anaerobic ammonium oxidation coupled to ferric iron reduction (feammox) and lithoautotrophic nitrate-reducing ferrous iron-oxidation (NRFeOx). These emerging findings continue to expand our knowledge of the nitrogen/iron cycle in nature and also highlight the need to re-understand the functional traits of the microorganisms involved. Here, as a proof-of-principle, we report compelling evidence for the capability of an NRFeOx enrichment culture to catalyze the feammox process. Our results demonstrate that the NRFeOx culture predominantly oxidizes NH4+ to nitrogen gas, by reducing both chelated nitrilotriacetic acid (NTA)-Fe(III) and poorly soluble Fe(III)-bearing minerals (γ-FeOOH) at pH 4.0 and 8.0, respectively. In the NRFeOx culture, Fe(II)-oxidizing bacteria of Rhodanobacter and Fe(III)-reducing bacteria of unclassified_Acidobacteriota coexisted. Their relative abundances were dynamically regulated by the supplemented iron sources. Metagenomic analysis revealed that the NRFeOx culture contained a complete set of denitrifying genes along with hao genes for ammonium oxidation. Additionally, numerous genes encoding extracellular electron transport-associated proteins or their homologs were identified, which facilitated the reduction of extracellular iron by this culture. More broadly, this work lightens the unexplored potential of specific microbial groups in driving nitrogen transformation through multiple pathways and highlights the essential role of microbial iron metabolism in the integral biogeochemical nitrogen cycle.
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Affiliation(s)
- Hong-Bin Zhang
- 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
| | - He-Fei Wang
- National Marine Environmental Monitoring Center, Laboratory of Island Ecological Environment Protection, Dalian 116023, China
| | - Jia-Bo Liu
- 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
| | - Zhen Bi
- School of Environment Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Ruo-Fei Jin
- 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
| | - Tian Tian
- 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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Corbera-Rubio F, Stouten GR, Bruins J, Dost SF, Merkel AY, Müller S, van Loosdrecht MCM, van Halem D, Laureni M. " Candidatus Siderophilus nitratireducens": a putative nap-dependent nitrate-reducing iron oxidizer within the new order Siderophiliales. ISME COMMUNICATIONS 2024; 4:ycae008. [PMID: 38577582 PMCID: PMC10993476 DOI: 10.1093/ismeco/ycae008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 01/03/2024] [Accepted: 01/17/2024] [Indexed: 04/06/2024]
Abstract
Nitrate leaching from agricultural soils is increasingly found in groundwater, a primary source of drinking water worldwide. This nitrate influx can potentially stimulate the biological oxidation of iron in anoxic groundwater reservoirs. Nitrate-dependent iron-oxidizing (NDFO) bacteria have been extensively studied in laboratory settings, yet their ecophysiology in natural environments remains largely unknown. To this end, we established a pilot-scale filter on nitrate-rich groundwater to elucidate the structure and metabolism of nitrate-reducing iron-oxidizing microbiomes under oligotrophic conditions mimicking natural groundwaters. The enriched community stoichiometrically removed iron and nitrate consistently with the NDFO metabolism. Genome-resolved metagenomics revealed the underlying metabolic network between the dominant iron-dependent denitrifying autotrophs and the less abundant organoheterotrophs. The most abundant genome belonged to a new Candidate order, named Siderophiliales. This new species, "Candidatus Siderophilus nitratireducens," carries genes central genes to iron oxidation (cytochrome c cyc2), carbon fixation (rbc), and for the sole periplasmic nitrate reductase (nap). Using thermodynamics, we demonstrate that iron oxidation coupled to nap based dissimilatory reduction of nitrate to nitrite is energetically favorable under realistic Fe3+/Fe2+ and NO3-/NO2- concentration ratios. Ultimately, by bridging the gap between laboratory investigations and nitrate real-world conditions, this study provides insights into the intricate interplay between nitrate and iron in groundwater ecosystems, and expands our understanding of NDFOs taxonomic diversity and ecological role.
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Affiliation(s)
| | - Gerben R Stouten
- Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
| | | | - Simon F Dost
- WMD Water Company Drenthe, Lauwers 3, 9405 BL Assen, the Netherlands
| | - Alexander Y Merkel
- Winogradsky Institute of Microbiology, Research Center of Biotechnology, Russian Academy of Sciences, 60 let Oktjabrja pr-t, 7, bld. 2, 117312 Moscow, Russia
| | - Simon Müller
- Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
| | | | - Doris van Halem
- Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
| | - Michele Laureni
- Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
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7
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Hao Z, Wang Q, Wang J, Deng Y, Yan Z, Tian L, Jiang H. Water Level Fluctuations Modulate the Microbiomes Involved in Biogeochemical Cycling in Floodplains. MICROBIAL ECOLOGY 2023; 87:24. [PMID: 38159125 DOI: 10.1007/s00248-023-02331-6] [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: 07/30/2023] [Accepted: 12/08/2023] [Indexed: 01/03/2024]
Abstract
Drastic changes in hydrological conditions within floodplain ecosystems create distinct microbial habitats. However, there remains a lack of exploration regarding the variations in microbial function potentials across the flooding and drought seasons. In this study, metagenomics and environmental analyses were employed in floodplains that experience hydrological variations across four seasons. Analysis of functional gene composition, encompassing nitrogen, carbon, and sulfur metabolisms, revealed apparent differences between the flooding and drought seasons. The primary environmental drivers identified were water level, overlying water depth, submergence time, and temperature. Specific modules, e.g., the hydrolysis of β-1,4-glucosidic bond, denitrification, and dissimilatory/assimilatory nitrate reduction to ammonium, exhibited higher relative abundance in summer compared to winter. It is suggested that cellulose degradation was potentially coupled with nitrate reduction during the flooding season. Phylogenomic analysis of metagenome-assembled genomes (MAGs) unveiled that the Desulfobacterota lineage possessed abundant nitrogen metabolism genes supported by pathway reconstruction. Variation of relative abundance implied its environmental adaptability to both the wet and dry seasons. Furthermore, a novel order was found within Methylomirabilota, containing nitrogen reduction genes in the MAG. Overall, this study highlights the crucial role of hydrological factors in modulating microbial functional diversity and generating genomes with abundant nitrogen metabolism potentials.
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Affiliation(s)
- Zheng Hao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Qianhong Wang
- Changjiang Nanjing Waterway Engineering Bureau, Nanjing, 210011, China
| | - Jianjun Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Ye Deng
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Zaisheng Yan
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Linqi Tian
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Helong Jiang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China.
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8
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Bayer T, Wei R, Kappler A, Byrne JM. Cu(II) and Cd(II) Removal Efficiency of Microbially Redox-Activated Magnetite Nanoparticles. ACS EARTH & SPACE CHEMISTRY 2023; 7:1837-1847. [PMID: 37876664 PMCID: PMC10591504 DOI: 10.1021/acsearthspacechem.2c00394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 09/26/2023] [Accepted: 09/26/2023] [Indexed: 10/26/2023]
Abstract
Heavy metal pollutants in the environment are of global concern due to their risk of contaminating drinking water and food supplies. Removal of these metals can be achieved by adsorption to mixed-valent magnetite nanoparticles (MNPs) due to their high surface area, reactivity, and ability for magnetic recovery. The adsorption capacity and overall efficiency of MNPs are influenced by redox state as well as surface charge, the latter of which is directly related to solution pH. However, the influence of microbial redox cycling of iron (Fe) in magnetite alongside the change of pH on the metal adsorption process by MNPs remains an open question. Here we investigated adsorption of Cd2+ and Cu2+ by MNPs at different pH values that were modified by microbial Fe(II) oxidation or Fe(III) reduction. We found that the maximum adsorption capacity increased with pH for Cd2+ from 256 μmol/g Fe at pH 5.0 to 478 μmol/g Fe at pH 7.3 and for Cu2+ from 229 μmol/g Fe at pH 5.0 to 274 μmol/g Fe at pH 5.5. Microbially reduced MNPs exhibited the greatest adsorption for both Cu2+ and Cd2+ (632 μmol/g Fe at pH 7.3 for Cd2+ and 530 μmol/g Fe at pH 5.5 for Cu2+). Magnetite oxidation also enhanced adsorption of Cu2+ but inhibited Cd2+. Our results show that microbial modification of MNPs has an important impact on the (im-)mobilization of aqueous contaminations like Cu2+ and Cd2+ and that a change in stoichiometry of the MNPs can have a greater influence than a change of pH.
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Affiliation(s)
- Timm Bayer
- Geomicrobiology
Group, Department of Geoscience, University
of Tuebingen, Schnarrenbergstrasse 94-96, 72076 Tuebingen, Germany
| | - Ran Wei
- Environmental
Systems Analysis, Department of Geoscience, University of Tuebingen, Schnarrenbergstrasse 94-96, 72076 Tuebingen, Germany
| | - Andreas Kappler
- Geomicrobiology
Group, Department of Geoscience, University
of Tuebingen, Schnarrenbergstrasse 94-96, 72076 Tuebingen, Germany
- Cluster
of Excellence: EXC 2124: Controlling Microbes to Fight Infection, 72074 Tuebingen, Germany
| | - James M. Byrne
- School
of Earth Sciences, University of Bristol, Wills Memorial Building, Queens
Road, BS8 1RJ Bristol, United Kingdom
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9
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Pan Y, Fu YY, Zhou K, Tian T, Li YS, Yu HQ. Microbial mixotrophic denitrification using iron(II) as an assisted electron donor. WATER RESEARCH X 2023; 19:100176. [PMID: 37020531 PMCID: PMC10068250 DOI: 10.1016/j.wroa.2023.100176] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 06/19/2023]
Abstract
Mixotrophic denitrification processes have a great potential in nitrogen removal in biological wastewater treatment processes. However, so far, few studies have focused on the mixotrophic denitrification system using Fe(II) as an exclusively assisted electron donors and the underlying mechanisms in such a process remain unclear. Furthermore, the mechanisms by which microorganisms cover carbon, nitrogen, phosphorus and iron in an iron-assisted mixotrophic system remain unrevealed. In this work, we explore the feasibility of using Fe(II) as an assisted electron donor for enhancing simultaneous nitrogen and phosphorus removal via long-term reactor operation and batch tests. The results show that Fe(II) could provide electrons for efficient nitrate reduction and that biological reactions played a predominant role in these systems. In these systems Thermomonas, a strain of nitrate-reduction Fe(II)-oxidation bacterium, was enriched and accounted for a maximum abundance of 60.2%. These findings indicate a great potential of the Fe(II)-assisted mixotrophic denitrification system for practical use as an efficient simultaneous nitrogen and phosphorus removal process.
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Affiliation(s)
- Yuan Pan
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
- Anhui Province Key Laboratory of Industrial Wastewater and Environmental Treatment, Hefei 230026, China
| | - Ying-Ying Fu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Ke Zhou
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Tian Tian
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
- 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
| | - Yu-Sheng Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
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10
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Bayer T, Tomaszewski EJ, Bryce C, Kappler A, Byrne JM. Continuous cultivation of the lithoautotrophic nitrate-reducing Fe(II)-oxidizing culture KS in a chemostat bioreactor. ENVIRONMENTAL MICROBIOLOGY REPORTS 2023. [PMID: 36992623 DOI: 10.1111/1758-2229.13149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 02/15/2023] [Indexed: 06/19/2023]
Abstract
Laboratory-based studies on microbial Fe(II) oxidation are commonly performed for 5-10 days in small volumes with high substrate concentrations, resulting in geochemical gradients and volumetric effects caused by sampling. We used a chemostat to enable uninterrupted supply of medium and investigated autotrophic nitrate-reducing Fe(II)-oxidizing culture KS for 24 days. We analysed Fe- and N-speciation, cell-mineral associations, and the identity of minerals. Results were compared to batch systems (50 and 700 mL-static/shaken). The Fe(II) oxidation rate was highest in the chemostat with 7.57 mM Fe(II) d-1 , while the extent of oxidation was similar to the other experimental setups (average oxidation of 92% of all Fe(II)). Short-range ordered Fe(III) phases, presumably ferrihydrite, precipitated and later goethite was detected in the chemostat. The 1 mM solid phase Fe(II) remained in the chemostat, up to 15 μM of reactive nitrite was measured, and 42% of visualized cells were partially or completely mineral-encrusted, likely caused by abiotic oxidation of Fe(II) by nitrite. Despite (partial) encrustation, cells were still viable. Our results show that even with similar oxidation rates as in batch cultures, cultivating Fe(II)-oxidizing microorganisms under continuous conditions reveals the importance of reactive nitrogen intermediates on Fe(II) oxidation, mineral formation and cell-mineral interactions.
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Affiliation(s)
- Timm Bayer
- Geomicrobiology Group, Center for Applied Geoscience, University of Tuebingen, Tuebingen, Germany
| | - Elizabeth J Tomaszewski
- Geomicrobiology Group, Center for Applied Geoscience, University of Tuebingen, Tuebingen, Germany
| | - Casey Bryce
- School of Earth Sciences, University of Bristol, Bristol, UK
| | - Andreas Kappler
- Geomicrobiology Group, Center for Applied Geoscience, University of Tuebingen, Tuebingen, Germany
- Cluster of Excellence: EXC 2124: Controlling Microbes to Fight Infection, Tuebingen, Germany
| | - James M Byrne
- School of Earth Sciences, University of Bristol, Bristol, UK
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Huang J, Mellage A, Garcia JP, Glöckler D, Mahler S, Elsner M, Jakus N, Mansor M, Jiang H, Kappler A. Metabolic Performance and Fate of Electrons during Nitrate-Reducing Fe(II) Oxidation by the Autotrophic Enrichment Culture KS Grown at Different Initial Fe/N Ratios. Appl Environ Microbiol 2023; 89:e0019623. [PMID: 36877057 PMCID: PMC10057050 DOI: 10.1128/aem.00196-23] [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: 02/07/2023] [Accepted: 02/11/2023] [Indexed: 03/07/2023] Open
Abstract
Autotrophic nitrate-reducing Fe(II)-oxidizing (NRFeOx) microorganisms fix CO2 and oxidize Fe(II) coupled to denitrification, influencing carbon, iron, and nitrogen cycles in pH-neutral, anoxic environments. However, the distribution of electrons from Fe(II) oxidation to either biomass production (CO2 fixation) or energy generation (nitrate reduction) in autotrophic NRFeOx microorganisms has not been quantified. We therefore cultivated the autotrophic NRFeOx culture KS at different initial Fe/N ratios, followed geochemical parameters, identified minerals, analyzed N isotopes, and applied numerical modeling. We found that at all initial Fe/N ratios, the ratios of Fe(II)oxidized to nitratereduced were slightly higher (5.11 to 5.94 at Fe/N ratios of 10:1 and 10:0.5) or lower (4.27 to 4.59 at Fe/N ratios of 10:4, 10:2, 5:2, and 5:1) than the theoretical ratio for 100% Fe(II) oxidation being coupled to nitrate reduction (5:1). The main N denitrification product was N2O (71.88 to 96.29% at Fe/15N ratios of 10:4 and 5:1; 43.13 to 66.26% at an Fe/15N ratio of 10:1), implying that denitrification during NRFeOx was incomplete in culture KS. Based on the reaction model, on average 12% of electrons from Fe(II) oxidation were used for CO2 fixation while 88% of electrons were used for reduction of NO3- to N2O at Fe/N ratios of 10:4, 10:2, 5:2, and 5:1. With 10 mM Fe(II) (and 4, 2, 1, or 0.5 mM nitrate), most cells were closely associated with and partially encrusted by the Fe(III) (oxyhydr)oxide minerals, whereas at 5 mM Fe(II), most cells were free of cell surface mineral precipitates. The genus Gallionella (>80%) dominated culture KS regardless of the initial Fe/N ratios. Our results showed that Fe/N ratios play a key role in regulating N2O emissions, for distributing electrons between nitrate reduction and CO2 fixation, and for the degree of cell-mineral interactions in the autotrophic NRFeOx culture KS. IMPORTANCE Autotrophic NRFeOx microorganisms that oxidize Fe(II), reduce nitrate, and produce biomass play a key role in carbon, iron, and nitrogen cycles in pH-neutral, anoxic environments. Electrons from Fe(II) oxidation are used for the reduction of both carbon dioxide and nitrate. However, the question is how many electrons go into biomass production versus energy generation during autotrophic growth. Here, we demonstrated that in the autotrophic NRFeOx culture KS cultivated at Fe/N ratios of 10:4, 10:2, 5:2, and 5:1, ca. 12% of electrons went into biomass formation, while 88% of electrons were used for reduction of NO3- to N2O. Isotope analysis also showed that denitrification during NRFeOx was incomplete in culture KS and the main N denitrification product was N2O. Therefore, most electrons stemming from Fe(II) oxidation seemed to be used for N2O formation in culture KS. This is environmentally important for the greenhouse gas budget.
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Affiliation(s)
- Jianrong Huang
- Geomicrobiology, Department of Geoscience, University of Tuebingen, Tuebingen, Germany
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Adrian Mellage
- Hydrogeology, Civil and Environmental Engineering, University of Kassel, Kassel, Germany
- Hydrogeology, Department of Geosciences, University of Tuebingen, Tuebingen, Germany
| | - Julian Pavon Garcia
- Hydrogeology, Department of Geosciences, University of Tuebingen, Tuebingen, Germany
| | - David Glöckler
- Analytical Chemistry and Water Chemistry, Technical University of Munich, Munich, Germany
| | - Susanne Mahler
- Analytical Chemistry and Water Chemistry, Technical University of Munich, Munich, Germany
| | - Martin Elsner
- Analytical Chemistry and Water Chemistry, Technical University of Munich, Munich, Germany
| | - Natalia Jakus
- Geomicrobiology, Department of Geoscience, University of Tuebingen, Tuebingen, Germany
- School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Muammar Mansor
- Geomicrobiology, Department of Geoscience, University of Tuebingen, Tuebingen, Germany
| | - Hongchen Jiang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Andreas Kappler
- Geomicrobiology, Department of Geoscience, University of Tuebingen, Tuebingen, Germany
- Cluster of Excellence, EXC 2124, Controlling Microbes to Fight Infection, Tuebingen, Germany
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12
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Visser AN, Wankel SD, Frey C, Kappler A, Lehmann MF. Unchanged nitrate and nitrite isotope fractionation during heterotrophic and Fe(II)-mixotrophic denitrification suggest a non-enzymatic link between denitrification and Fe(II) oxidation. Front Microbiol 2022; 13:927475. [PMID: 36118224 PMCID: PMC9478938 DOI: 10.3389/fmicb.2022.927475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 07/29/2022] [Indexed: 11/13/2022] Open
Abstract
Natural-abundance measurements of nitrate and nitrite (NOx) isotope ratios (δ15N and δ18O) can be a valuable tool to study the biogeochemical fate of NOx species in the environment. A prerequisite for using NOx isotopes in this regard is an understanding of the mechanistic details of isotope fractionation (15ε, 18ε) associated with the biotic and abiotic NOx transformation processes involved (e.g., denitrification). However, possible impacts on isotope fractionation resulting from changing growth conditions during denitrification, different carbon substrates, or simply the presence of compounds that may be involved in NOx reduction as co-substrates [e.g., Fe(II)] remain uncertain. Here we investigated whether the type of organic substrate, i.e., short-chained organic acids, and the presence/absence of Fe(II) (mixotrophic vs. heterotrophic growth conditions) affect N and O isotope fractionation dynamics during nitrate (NO3–) and nitrite (NO2–) reduction in laboratory experiments with three strains of putative nitrate-dependent Fe(II)-oxidizing bacteria and one canonical denitrifier. Our results revealed that 15ε and 18ε values obtained for heterotrophic (15ε-NO3–: 17.6 ± 2.8‰, 18ε-NO3–:18.1 ± 2.5‰; 15ε-NO2–: 14.4 ± 3.2‰) vs. mixotrophic (15ε-NO3–: 20.2 ± 1.4‰, 18ε-NO3–: 19.5 ± 1.5‰; 15ε-NO2–: 16.1 ± 1.4‰) growth conditions are very similar and fall within the range previously reported for classical heterotrophic denitrification. Moreover, availability of different short-chain organic acids (succinate vs. acetate), while slightly affecting the NOx reduction dynamics, did not produce distinct differences in N and O isotope effects. N isotope fractionation in abiotic controls, although exhibiting fluctuating results, even expressed transient inverse isotope dynamics (15ε-NO2–: –12.4 ± 1.3 ‰). These findings imply that neither the mechanisms ordaining cellular uptake of short-chain organic acids nor the presence of Fe(II) seem to systematically impact the overall N and O isotope effect during NOx reduction. The similar isotope effects detected during mixotrophic and heterotrophic NOx reduction, as well as the results obtained from the abiotic controls, may not only imply that the enzymatic control of NOx reduction in putative NDFeOx bacteria is decoupled from Fe(II) oxidation, but also that Fe(II) oxidation is indirectly driven by biologically (i.e., via organic compounds) or abiotically (catalysis via reactive surfaces) mediated processes co-occurring during heterotrophic denitrification.
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Affiliation(s)
- Anna-Neva Visser
- Aquatic and Isotope Biogeochemistry, Department of Environmental Sciences, Basel University, Basel, Switzerland
- *Correspondence: Anna-Neva Visser,
| | - Scott D. Wankel
- Stable Isotope Biogeochemistry, Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Falmouth, MA, United States
| | - Claudia Frey
- Aquatic and Isotope Biogeochemistry, Department of Environmental Sciences, Basel University, Basel, Switzerland
| | - Andreas Kappler
- Geomicrobiology, Center for Applied Geosciences, Eberhard Karls University, Tuebingen, Germany
- Cluster of Excellence: EXC 2124: Controlling Microbes to Fight Infection, Tuebingen, Germany
| | - Moritz F. Lehmann
- Aquatic and Isotope Biogeochemistry, Department of Environmental Sciences, Basel University, Basel, Switzerland
- Moritz F. Lehmann,
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Fan X, Li J, He L, Wang Y, Zhou J, Zhou J, Liu C. Co-occurrence of autotrophic and heterotrophic denitrification in electrolysis assisted constructed wetland packing with coconut fiber as solid carbon source. CHEMOSPHERE 2022; 301:134762. [PMID: 35490751 DOI: 10.1016/j.chemosphere.2022.134762] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 04/06/2022] [Accepted: 04/25/2022] [Indexed: 06/14/2023]
Abstract
Aiming at the problems of lack of carbon sources for nitrogen removal and low phosphorus removal efficiency of constructed wetlands (CWs) in treating wastewater treatment plant (WWTP) effluent, an electrolysis assisted constructed wetland (E-CW) with coconut fiber as substrate and solid carbon sources was constructed. The synthetic secondary effluent was used as the influent of the E-CW with a wastewater treatment capacity of 140 L d-1. The total nitrogen (TN) and the total phosphorus (TP) removal efficiency of the E-CW with coconut fiber treating WWTP effluent were 69.4% and 93.3%, respectively, which were 54.3% and 88.2% higher than those of CW with coconut fiber and no electrolysis. The removal efficiency of TN was 39.9% higher than that of E-CW with gravel. The current intensity had significant effect on nitrogen removal efficiency and the release of carbon sources from coconut fiber. When current intensity increased from 0.25 A to 1.00 A, the TN removal efficiency and nitrate removal rate increased by 21.1% and 0.21 mg L-1 h-1, respectively, and the volatile fatty acids (VFAs) released from coconut fiber increased by 57.7 mg L-1. The 16S rRNA high-throughput sequencing results indicated that the main functional nitrogen-removing microbes were Hydrogenophaga, Thauera, Rhodanobacteraceae_norank, Xanthobacteraceae_norank, etc. Multiple paths including autotrophic denitrification with hydrogen and Fe2+ as electron donors and heterotrophic denitrification were achieved in the system. Meanwhile, the main functional lignocellulose degradation microbes were enriched in the system, including Cytophaga_xylanolytica_group, and Caldilineaceae. Because electrolysis created a favorable environment for them to release carbon sources from coconut fiber. This study provided a new perspective for advanced nutrients removal of WWTP effluent in CWs.
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Affiliation(s)
- Xing Fan
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Jiao Li
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Lei He
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Yingmu Wang
- College of Civil Engineering, Fuzhou University, Fuzhou, Fujian, 350116, PR China
| | - Jiong Zhou
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Jian Zhou
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Caihong Liu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China.
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14
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Chakraborty A, Suchy M, Hubert CRJ, Ryan MC. Vertical stratification of microbial communities and isotope geochemistry tie groundwater denitrification to sampling location within a nitrate-contaminated aquifer. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 820:153092. [PMID: 35038526 DOI: 10.1016/j.scitotenv.2022.153092] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 12/29/2021] [Accepted: 01/09/2022] [Indexed: 06/14/2023]
Abstract
Nitrate pollution is a major threat to groundwater quality in agricultural areas. Natural attenuation of nitrate in contaminated aquifers is mediated by denitrifying microbial populations in anoxic environments. Vertical distribution of denitrifying microbial communities in aquifers is greatly influenced by groundwater redox conditions, local hydrogeological parameters, and seasonal variability in groundwater flow and recharge. In this study, we investigated groundwater geochemistry and the composition of bacterial and archaeal communities with increasing depth in a shallow nitrate-contaminated aquifer in British Columbia, Canada. High-resolution passive diffusion sampling was conducted to collect groundwater at 10-cm intervals from 4 to 20 m below ground surface (mbgs) in the aquifer. Geochemical analyses of major ions indicated a general shift in the groundwater chemistry below 16 mbgs including decreasing chloride concentrations that suggest two-end member mixing of shallow and deep groundwater with different chemistries. A redoxcline was further observed within a 2 m transition zone at 18-20 mbgs characterized by sharp declines in nitrate concentrations and increases in sulfate and total inorganic carbon. Excursions in δ15N-NO3- and δ18O-NO3- in the same depth interval are consistent with denitrification, and a concomitant decrease in δ34S-SO42- suggested that denitrification was coupled to sulfide or sulfur oxidation. Microbial communities within this depth interval were significantly dissimilar to those above and below, featuring putative lithotrophic denitrifying bacteria belonging to the genera Sulfurifustis, Sulfuritalea and Sulfuricella. These lineages were detected in greatest abundance at 19 mbgs while the abundances of putative heterotrophic sulfate-reducing bacteria belonging to the genus Desulfosporosinus were greatest at 20 mbgs. In addition to help distinguish denitrification from mixing-induced changes in groundwater chemistry, the above observed vertical stratification of the microbial key players connects nitrate removal to the locations of the aquifer sampled.
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Affiliation(s)
- Anirban Chakraborty
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
| | - Martin Suchy
- Environment and Climate Change Canada, Vancouver, British Columbia, Canada
| | - Casey R J Hubert
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - M Cathryn Ryan
- Department of Geoscience, University of Calgary, Calgary, Alberta, Canada
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15
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Salinity Impact on Composition and Activity of Nitrate-Reducing Fe(II)-Oxidizing Microorganisms in Saline Lakes. Appl Environ Microbiol 2022; 88:e0013222. [PMID: 35499328 DOI: 10.1128/aem.00132-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nitrate-reducing Fe(II)-oxidizing (NRFeOx) microorganisms contribute to nitrogen, carbon, and iron cycling in freshwater and marine ecosystems. However, NRFeOx microorganisms have not been investigated in hypersaline lakes, and their identity, as well as their activity in response to salinity, is unknown. In this study, we combined cultivation-based most probable number (MPN) counts with Illumina MiSeq sequencing to analyze the abundance and community compositions of NRFeOx microorganisms enriched from five lake sediments with different salinities (ranging from 0.67 g/L to 346 g/L). MPN results showed that the abundance of NRFeOx microorganisms significantly (P < 0.05) decreased with increasing lake salinity, from 7.55 × 103 to 8.09 cells/g dry sediment. The community composition of the NRFeOx enrichment cultures obtained from the MPNs differed distinctly among the five lakes and clustered with lake salinity. Two stable enrichment cultures, named FeN-EHL and FeN-CKL, were obtained from microcosm incubations of sediment from freshwater Lake Erhai and hypersaline Lake Chaka. The culture FeN-EHL was dominated by genus Gallionella (68.4%), while the culture FeN-CKL was dominated by genus Marinobacter (71.2%), with the former growing autotrophically and the latter requiring an additional organic substrate (acetate) and Fe(II) oxidation, caused to a large extent by chemodenitrification [reaction of nitrite with Fe(II)]. Short-range ordered Fe(III) (oxyhydr)oxides were the product of Fe(II) oxidation, and the cells were partially attached to or encrusted by the formed iron minerals in both cultures. In summary, different types of interactions between Fe(II) and nitrate-reducing bacteria may exist in freshwater and hypersaline lakes, i.e., autotrophic NRFeOx and chemodenitrification in freshwater and hypersaline environments, respectively. IMPORTANCE NRFeOx microorganisms are globally distributed in various types of environments and play a vital role in iron transformation and nitrate and heavy metal removal. However, most known NRFeOx microorganisms were isolated from freshwater and marine environments, while their identity and activity under hypersaline conditions remain unknown. Here, we demonstrated that salinity may affect the abundance, identity, and nutrition modes of NRFeOx microorganisms. Autotrophy was only detectable in a freshwater lake but not in the saline lake investigated. We enriched a mixotrophic culture capable of nitrate-reducing Fe(II) oxidation from hypersaline lake sediments. However, Fe(II) oxidation was probably caused by abiotic nitrite reduction (chemodenitrification) rather than by a biologically mediated process. Consequently, our study suggests that in hypersaline environments, Fe(II) oxidation is largely caused by chemodentrification initiated by nitrite formation by chemoheterotrophic bacteria, and additional experiments are needed to demonstrate whether or to what extent Fe(II) is enzymatically oxidized.
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16
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‘Candidatus ferrigenium straubiae’ sp. nov., ‘Candidatus ferrigenium bremense’ sp. nov., ‘Candidatus ferrigenium altingense’ sp. nov., are autotrophic Fe(II)-oxidizing bacteria of the family Gallionellaceae. Syst Appl Microbiol 2022; 45:126306. [DOI: 10.1016/j.syapm.2022.126306] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 02/06/2022] [Accepted: 02/07/2022] [Indexed: 01/04/2023]
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17
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Tian T, Zhou K, Li YS, Liu DF, Yu HQ. Recovery of Iron-Dependent Autotrophic Denitrification Activity from Cell-Iron Mineral Aggregation-Induced Reversible Inhibition by Low-Intensity Ultrasonication. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:595-604. [PMID: 34932326 DOI: 10.1021/acs.est.1c05553] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Iron-dependent autotrophic denitrification (IDAD) has garnered increasing interests as an efficient method for removing nitrogen from wastewater with a low carbon to nitrogen ratio. However, an inevitable deterioration of IDAD performance casts a shadow over its further development. In this work, the hidden cause for such a deterioration is uncovered, and a viable solution to this problem is provided. Batch test results reveal that the aggregation of microbial cells and iron-bearing minerals induced a cumulative and reversible inhibition on the activity of IDAD sludge. Extracellular polymeric substances were found to play a glue-like role in the cell-iron mineral aggregates, where microbial cells were caged, and their metabolisms were suppressed. Adopting low-intensity ultrasound treatment efficiently restored the IDAD activity by disintegrating such aggregates rather than stimulating the microbial metabolism. Moreover, the ultrasonication-assisted IDAD bioreactor exhibited an advantageous nitrogen removal efficiency (with a maximum enhancement of 72.3%) and operational stability compared to the control one, demonstrating a feasible strategy to achieve long-term stability of the IDAD process. Overall, this work provides a better understanding about the mechanism for the performance deterioration and a simple approach to maintain the stability of IDAD.
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Affiliation(s)
- Tian Tian
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
- 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
| | - Ke Zhou
- School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China
| | - Yu-Sheng Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Dong-Feng Liu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
- School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China
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Pang Y, Wang J. Various electron donors for biological nitrate removal: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 794:148699. [PMID: 34214813 DOI: 10.1016/j.scitotenv.2021.148699] [Citation(s) in RCA: 144] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/22/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
Nitrate (NO3-) pollution in water and wastewater has become a serious global issue. Biological denitrification, which reduces NO3- to N2 (nitrogen gas) by denitrifying microorganisms, is an efficient and economical process for the removal of NO3- from water and wastewater. During the denitrification process, electron donor is required to provide electrons for reduction of NO3-. A variety of electron donors, including organic and inorganic compounds, can be used for denitrification. This paper reviews the state of the art of various electron donors used for biological denitrification. Depending on the types of electron donors, denitrification can be classified into heterotrophic and autotrophic denitrification. Heterotrophic denitrification utilizes organic compounds as electron donors, including low-molecular-weight organics (e.g. acetate, methanol, glucose, benzene, methane, etc.) and high-molecular-weight organics (e.g. cellulose, polylactic acid, polycaprolactone, etc.); while autotrophic denitrification utilizes inorganic compounds as electron donors, including hydrogen (H2), reduced sulfur compounds (e.g. sulfide, element sulfur and thiosulfate), ferrous iron (Fe2+), iron sulfides (e.g. FeS, Fe1-xS and FeS2), arsenite (As(Ш)) and manganese (Mn(II)). The biological denitrification processes and the representative denitrifying microorganisms are summarized based on different electron donors, and their denitrification performance, operating costs and environmental impacts are compared and discussed. The pilot- or full-scale applications were summarized. The concluding remarks and future prospects were provided. The biodegradable polymers mediated heterotrophic denitrification, as well as H2 and sulfur mediated autotrophic denitrification are promising denitrification processes for NO3- removal from various types of water and wastewater.
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Affiliation(s)
- Yunmeng Pang
- Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084, PR China
| | - Jianlong Wang
- Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084, PR China; Beijing Key Laboratory of Radioactive Waste Treatment, INET, Tsinghua University, Beijing 100084, PR China.
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Nitrate Removal by a Novel Lithoautotrophic Nitrate-Reducing, Iron(II)-Oxidizing Culture Enriched from a Pyrite-Rich Limestone Aquifer. Appl Environ Microbiol 2021; 87:e0046021. [PMID: 34085863 DOI: 10.1128/aem.00460-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nitrate removal in oligotrophic environments is often limited by the availability of suitable organic electron donors. Chemolithoautotrophic bacteria may play a key role in denitrification in aquifers depleted in organic carbon. Under anoxic and circumneutral pH conditions, iron(II) was hypothesized to serve as an electron donor for microbially mediated nitrate reduction by Fe(II)-oxidizing (NRFeOx) microorganisms. However, lithoautotrophic NRFeOx cultures have never been enriched from any aquifer, and as such, there are no model cultures available to study the physiology and geochemistry of this potentially environmentally relevant process. Using iron(II) as an electron donor, we enriched a lithoautotrophic NRFeOx culture from nitrate-containing groundwater of a pyrite-rich limestone aquifer. In the enriched NRFeOx culture that does not require additional organic cosubstrates for growth, within 7 to 11 days, 0.3 to 0.5 mM nitrate was reduced and 1.3 to 2 mM iron(II) was oxidized, leading to a stoichiometric NO3-/Fe(II) ratio of 0.2, with N2 and N2O identified as the main nitrate reduction products. Short-range ordered Fe(III) (oxyhydr)oxides were the product of iron(II) oxidation. Microorganisms were observed to be closely associated with formed minerals, but only few cells were encrusted, suggesting that most of the bacteria were able to avoid mineral precipitation at their surface. Analysis of the microbial community by long-read 16S rRNA gene sequencing revealed that the culture is dominated by members of the Gallionellaceae family that are known as autotrophic, neutrophilic, and microaerophilic iron(II) oxidizers. In summary, our study suggests that NRFeOx mediated by lithoautotrophic bacteria can lead to nitrate removal in anthropogenically affected aquifers. IMPORTANCE Removal of nitrate by microbial denitrification in groundwater is often limited by low concentrations of organic carbon. In these carbon-poor ecosystems, nitrate-reducing bacteria that can use inorganic compounds such as Fe(II) (NRFeOx) as electron donors could play a major role in nitrate removal. However, no lithoautotrophic NRFeOx culture has been successfully isolated or enriched from this type of environment, and as such, there are no model cultures available to study the rate-limiting factors of this potentially important process. Here, we present the physiology and microbial community composition of a novel lithoautotrophic NRFeOx culture enriched from a fractured aquifer in southern Germany. The culture is dominated by a putative Fe(II) oxidizer affiliated with the Gallionellaceae family and performs nitrate reduction coupled to Fe(II) oxidation leading to N2O and N2 formation without the addition of organic substrates. Our analyses demonstrate that lithoautotrophic NRFeOx can potentially lead to nitrate removal in nitrate-contaminated aquifers.
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Huang YM, Straub D, Blackwell N, Kappler A, Kleindienst S. Meta-omics Reveal Gallionellaceae and Rhodanobacter Species as Interdependent Key Players for Fe(II) Oxidation and Nitrate Reduction in the Autotrophic Enrichment Culture KS. Appl Environ Microbiol 2021; 87:e0049621. [PMID: 34020935 PMCID: PMC8276803 DOI: 10.1128/aem.00496-21] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 05/16/2021] [Indexed: 01/04/2023] Open
Abstract
Nitrate reduction coupled to Fe(II) oxidation (NRFO) has been recognized as an environmentally important microbial process in many freshwater ecosystems. However, well-characterized examples of autotrophic nitrate-reducing Fe(II)-oxidizing bacteria are rare, and their pathway of electron transfer as well as their interaction with flanking community members remain largely unknown. Here, we applied meta-omics (i.e., metagenomics, metatranscriptomics, and metaproteomics) to the nitrate-reducing Fe(II)-oxidizing enrichment culture KS growing under autotrophic or heterotrophic conditions and originating from freshwater sediment. We constructed four metagenome-assembled genomes with an estimated completeness of ≥95%, including the key players of NRFO in culture KS, identified as Gallionellaceae sp. and Rhodanobacter sp. The Gallionellaceae sp. and Rhodanobacter sp. transcripts and proteins likely involved in Fe(II) oxidation (e.g., mtoAB, cyc2, and mofA), denitrification (e.g., napGHI), and oxidative phosphorylation (e.g., respiratory chain complexes I to V) along with Gallionellaceae sp. transcripts and proteins for carbon fixation (e.g., rbcL) were detected. Overall, our results indicate that in culture KS, the Gallionellaceae sp. and Rhodanobacter sp. are interdependent: while Gallionellaceae sp. fixes CO2 and provides organic compounds for Rhodanobacter sp., Rhodanobacter sp. likely detoxifies NO through NO reduction and completes denitrification, which cannot be performed by Gallionellaceae sp. alone. Additionally, the transcripts and partial proteins of cbb3- and aa3-type cytochrome c suggest the possibility for a microaerophilic lifestyle of the Gallionellaceae sp., yet culture KS grows under anoxic conditions. Our findings demonstrate that autotrophic NRFO is performed through cooperation among denitrifying and Fe(II)-oxidizing bacteria, which might resemble microbial interactions in freshwater environments. IMPORTANCE Nitrate-reducing Fe(II)-oxidizing bacteria are widespread in the environment, contribute to nitrate removal, and influence the fate of the greenhouse gases nitrous oxide and carbon dioxide. The autotrophic growth of nitrate-reducing Fe(II)-oxidizing bacteria is rarely investigated and not fully understood. The most prominent model system for this type of study is the enrichment culture KS. To gain insights into the metabolism of nitrate reduction coupled to Fe(II) oxidation in the absence of organic carbon and oxygen, we performed metagenomic, metatranscriptomic, and metaproteomic analyses of culture KS and identified Gallionellaceae sp. and Rhodanobacter sp. as interdependent key Fe(II) oxidizers in culture KS. Our work demonstrates that autotrophic nitrate reduction coupled to Fe(II) oxidation is not performed by an individual strain but is a cooperation of at least two members of the bacterial community in culture KS. These findings serve as a foundation for our understanding of nitrate-reducing Fe(II)-oxidizing bacteria in the environment.
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Affiliation(s)
- Yu-Ming Huang
- Microbial Ecology, Center for Applied Geoscience, University of Tübingen, Tübingen, Germany
- Geomicrobiology, Center for Applied Geoscience, University of Tübingen, Tübingen, Germany
| | - Daniel Straub
- Microbial Ecology, Center for Applied Geoscience, University of Tübingen, Tübingen, Germany
- Quantitative Biology Center (QBiC), University of Tübingen, Tübingen, Germany
| | - Nia Blackwell
- Microbial Ecology, Center for Applied Geoscience, University of Tübingen, Tübingen, Germany
| | - Andreas Kappler
- Geomicrobiology, Center for Applied Geoscience, University of Tübingen, Tübingen, Germany
- Cluster of Excellence, EXC 2124, “Controlling Microbes to Fight Infections,” University of Tübingen, Tübingen, Germany
| | - Sara Kleindienst
- Microbial Ecology, Center for Applied Geoscience, University of Tübingen, Tübingen, Germany
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21
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Huang YM, Straub D, Kappler A, Smith N, Blackwell N, Kleindienst S. A Novel Enrichment Culture Highlights Core Features of Microbial Networks Contributing to Autotrophic Fe(II) Oxidation Coupled to Nitrate Reduction. Microb Physiol 2021; 31:280-295. [PMID: 34218232 DOI: 10.1159/000517083] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 05/03/2021] [Indexed: 11/19/2022]
Abstract
Fe(II) oxidation coupled to nitrate reduction (NRFO) has been described for many environments. Yet very few autotrophic microorganisms catalysing NRFO have been cultivated and their diversity, as well as their mechanisms for NRFO in situ remain unclear. A novel autotrophic NRFO enrichment culture, named culture BP, was obtained from freshwater sediment. After more than 20 transfers, culture BP oxidized 8.22 mM of Fe(II) and reduced 2.42 mM of nitrate within 6.5 days under autotrophic conditions. We applied metagenomic, metatranscriptomic, and metaproteomic analyses to culture BP to identify the microorganisms involved in autotrophic NRFO and to unravel their metabolism. Overall, twelve metagenome-assembled genomes (MAGs) were constructed, including a dominant Gallionellaceae sp. MAG (≥71% relative abundance). Genes and transcripts associated with potential Fe(II) oxidizers in culture BP, identified as a Gallionellaceae sp., Noviherbaspirillum sp., and Thiobacillus sp., were likely involved in metal oxidation (e.g., cyc2, mtoA), denitrification (e.g., nirK/S, norBC), carbon fixation (e.g., rbcL), and oxidative phosphorylation. The putative Fe(II)-oxidizing protein Cyc2 was detected for the Gallionellaceae sp. Overall, a complex network of microbial interactions among several Fe(II) oxidizers and denitrifiers was deciphered in culture BP that might resemble NRFO mechanisms in situ. Furthermore, 16S rRNA gene amplicon sequencing from environmental samples revealed 36 distinct Gallionellaceae taxa, including the key player of NRFO from culture BP (approx. 0.13% relative abundance in situ). Since several of these in situ-detected Gallionellaceae taxa were closely related to the key player in culture BP, this suggests that the diversity of organisms contributing to NRFO might be higher than currently known.
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Affiliation(s)
- Yu-Ming Huang
- Microbial Ecology, Center for Applied Geoscience, University of Tuebingen, Tuebingen, Germany.,Geomicrobiology, Center for Applied Geoscience, University of Tuebingen, Tuebingen, Germany
| | - Daniel Straub
- Microbial Ecology, Center for Applied Geoscience, University of Tuebingen, Tuebingen, Germany.,Quantitative Biology Center (QBiC), University of Tuebingen, Tuebingen, Germany
| | - Andreas Kappler
- Geomicrobiology, Center for Applied Geoscience, University of Tuebingen, Tuebingen, Germany.,Cluster of Excellence, EXC 2124, "Controlling Microbes to Fight Infections," University of Tübingen, Tübingen, Germany
| | - Nicole Smith
- Microbial Ecology, Center for Applied Geoscience, University of Tuebingen, Tuebingen, Germany
| | - Nia Blackwell
- Microbial Ecology, Center for Applied Geoscience, University of Tuebingen, Tuebingen, Germany
| | - Sara Kleindienst
- Microbial Ecology, Center for Applied Geoscience, University of Tuebingen, Tuebingen, Germany
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22
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Huang J, Jones A, Waite TD, Chen Y, Huang X, Rosso KM, Kappler A, Mansor M, Tratnyek PG, Zhang H. Fe(II) Redox Chemistry in the Environment. Chem Rev 2021; 121:8161-8233. [PMID: 34143612 DOI: 10.1021/acs.chemrev.0c01286] [Citation(s) in RCA: 177] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Iron (Fe) is the fourth most abundant element in the earth's crust and plays important roles in both biological and chemical processes. The redox reactivity of various Fe(II) forms has gained increasing attention over recent decades in the areas of (bio) geochemistry, environmental chemistry and engineering, and material sciences. The goal of this paper is to review these recent advances and the current state of knowledge of Fe(II) redox chemistry in the environment. Specifically, this comprehensive review focuses on the redox reactivity of four types of Fe(II) species including aqueous Fe(II), Fe(II) complexed with ligands, minerals bearing structural Fe(II), and sorbed Fe(II) on mineral oxide surfaces. The formation pathways, factors governing the reactivity, insights into potential mechanisms, reactivity comparison, and characterization techniques are discussed with reference to the most recent breakthroughs in this field where possible. We also cover the roles of these Fe(II) species in environmental applications of zerovalent iron, microbial processes, biogeochemical cycling of carbon and nutrients, and their abiotic oxidation related processes in natural and engineered systems.
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Affiliation(s)
- Jianzhi Huang
- Department of Civil and Environmental Engineering, Case Western Reserve University, 2104 Adelbert Road, Cleveland, Ohio 44106, United States
| | - Adele Jones
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - T David Waite
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Yiling Chen
- Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Xiaopeng Huang
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Kevin M Rosso
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Andreas Kappler
- Geomicrobiology, Center for Applied Geosciences, University of Tuebingen, 72076 Tuebingen, Germany
| | - Muammar Mansor
- Geomicrobiology, Center for Applied Geosciences, University of Tuebingen, 72076 Tuebingen, Germany
| | - Paul G Tratnyek
- School of Public Health, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Huichun Zhang
- Department of Civil and Environmental Engineering, Case Western Reserve University, 2104 Adelbert Road, Cleveland, Ohio 44106, United States
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23
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Iron-assisted biological wastewater treatment: Synergistic effect between iron and microbes. Biotechnol Adv 2020; 44:107610. [DOI: 10.1016/j.biotechadv.2020.107610] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/06/2020] [Accepted: 08/08/2020] [Indexed: 12/21/2022]
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24
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Tian T, Zhou K, Li YS, Liu DF, Yu HQ. Phosphorus Recovery from Wastewater Prominently through a Fe(II)-P Oxidizing Pathway in the Autotrophic Iron-Dependent Denitrification Process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11576-11583. [PMID: 32790298 DOI: 10.1021/acs.est.0c02882] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Phosphorus (P) recovery from wastewater can be completed by iron-involved autotrophic denitrification via forming Fe(III)-P precipitates and/or adsorbing P onto Fe(III) oxyhydroxides. However, so far, most studies focused on the final P-containing products, while the P-capturing pathways in such a process remain unclear. In this work, autotrophic iron-dependent denitrification (AIDD) was used as a typical anoxic iron-involved P-capturing biosystem to investigate the main P recovery pathways. The AIDD biosystem showed a relatively stable capability of capturing P coupled with nitrate reduction. Direct formation of amorphous Fe(II)-P precipitates after the phosphate was fed, followed by microbially driven oxidation into Fe(III)-P minerals, was found to be the primary pathway for the P capture. In addition, adsorption of phosphate onto the formed iron oxyhydroxides also contributed to the P recovery. This work provides better understanding about recovering P in AIDD and iron-involved denitrification and highlights the important roles of iron oxidizers in the iron-related biological wastewater treatment processes.
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Affiliation(s)
- Tian Tian
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Ke Zhou
- School of Resources & Environmental Engineering, Hefei University of Technology, Hefei 230009, China
| | - Yu-Sheng Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Dong-Feng Liu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
- School of Resources & Environmental Engineering, Hefei University of Technology, Hefei 230009, China
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25
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Fuchsman CA, Stüeken EE. Using modern low-oxygen marine ecosystems to understand the nitrogen cycle of the Paleo- and Mesoproterozoic oceans. Environ Microbiol 2020; 23:2801-2822. [PMID: 32869502 DOI: 10.1111/1462-2920.15220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 11/29/2022]
Abstract
During the productive Paleoproterozoic (2.4-1.8 Ga) and less productive Mesoproterozoic (1.8-1.0 Ga), the ocean was suboxic to anoxic and multicellular organisms had not yet evolved. Here, we link geologic information about the Proterozoic ocean to microbial processes in modern low-oxygen systems. High iron concentrations and rates of Fe cycling in the Proterozoic are the largest differences from modern oxygen-deficient zones. In anoxic waters, which composed most of the Paleoproterozoic and ~40% of the Mesoproterozoic ocean, nitrogen cycling dominated. Rates of N2 production by denitrification and anammox were likely linked to sinking organic matter fluxes and in situ primary productivity under anoxic conditions. Additionally autotrophic denitrifiers could have used reduced iron or methane. 50% of the Mesoproterozoic ocean may have been suboxic, promoting nitrification and metal oxidation in the suboxic water and N2 O and N2 production by partial and complete denitrification in anoxic zones in organic aggregates. Sulfidic conditions may have composed ~10% of the Mesoproterozoic ocean focused along continental margins. Due to low nitrate concentrations in offshore regions, anammox bacteria likely dominated N2 production immediately above sulfidic zones, but in coastal regions, higher nitrate concentrations probably promoted complete S-oxidizing autotrophic denitrification at the sulfide interface.
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Affiliation(s)
- Clara A Fuchsman
- Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, MD, 21613, USA
| | - Eva E Stüeken
- School of Earth & Environmental Sciences, University of St Andrews, St Andrews, KY16 9AL, Scotland, UK
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26
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Hu Y, Wu G, Li R, Xiao L, Zhan X. Iron sulphides mediated autotrophic denitrification: An emerging bioprocess for nitrate pollution mitigation and sustainable wastewater treatment. WATER RESEARCH 2020; 179:115914. [PMID: 32413614 DOI: 10.1016/j.watres.2020.115914] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 03/16/2020] [Accepted: 05/02/2020] [Indexed: 05/09/2023]
Abstract
Iron sulphides, mainly in the form of mackinawite (FeS), pyrrhotite (Fe1-xS, x = 0-0.125) and pyrite (FeS2), are the most abundant sulphide minerals and can be oxidized under anoxic and circumneutral pH conditions by chemoautotrophic denitrifying bacteria to reduce nitrate to N2. Iron sulphides mediated autotrophic denitrification (ISAD) represents an important natural attenuation process of nitrate pollution and plays a pivotal role in linking nitrogen, sulphur and iron cycles in a variety of anoxic environments. Recently, it has emerged as a promising bioprocess for nutrient removal from various organic-deficient water and wastewater, due to its specific advantages including high denitrification capacity, simultaneous nitrogen and phosphorus removal, self-buffering properties, and fewer by-products generation (sulphate, waste sludge, N2O, NH4+, etc.). This paper provides a critical overview of fundamental and engineering aspects of ISAD, including the theoretical knowledge (biochemistry, and microbial diversity), its natural occurrence and engineering applications. Its potential and limitations are elucidated by summarizing the key influencing factors including availability of iron sulphides, low denitrification rates, sulphate emission and leaching heavy metals. This review also put forward two key questions in the mechanism of anoxic iron sulphides oxidation, i.e. dissolution of iron sulphides and direct substrates for denitrifiers. Finally, its prospects for future sustainable wastewater treatment are highlighted. An iron sulphides-based biotechnology towards next-generation wastewater treatment (NEO-GREEN) is proposed, which can potentially harness bioenergy in wastewater, incorporate resources (P and Fe) recovery, achieve simultaneous nutrient and emerging contaminants removal, and minimize waste sludge production.
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Affiliation(s)
- Yuansheng Hu
- Civil Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Ireland; Ryan Institute, National University of Ireland, Galway, Ireland
| | - Guangxue Wu
- Institute of Environmental Engineering and Management, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, China
| | - Ruihua Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163# Xianlin Avenue, Nanjing, 210023, China
| | - Liwen Xiao
- Department of Civil, Structural and Environmental Engineering, Trinity College Dublin, Dublin 2, Ireland
| | - Xinmin Zhan
- Civil Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Ireland; Ryan Institute, National University of Ireland, Galway, Ireland; MaREI Centre for Marine and Renewable Energy, Ireland.
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27
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Tian T, Yu HQ. Denitrification with non-organic electron donor for treating low C/N ratio wastewaters. BIORESOURCE TECHNOLOGY 2020; 299:122686. [PMID: 31902635 DOI: 10.1016/j.biortech.2019.122686] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/21/2019] [Accepted: 12/23/2019] [Indexed: 05/21/2023]
Abstract
Denitrification with non-organic electron donors for treating low C/N ratio wastewater has attracted growing interests. Hydrogen, reduced sulfur compounds and ferrous ions are mainly used in autotrophic denitrification, holding promise for achieving practical applications. Recently, the development of autotrophic denitrification-based processes, such as bioelectrochemically-supported hydrogenotrophic denitrification and sulfur-/iron-based denitrification assisted multi-contaminant removal, provide opportunities for applying these processes in wastewater treatment. Exploration of the autotrophic denitrification process in terms of contaminant removal mechanism, interaction among functional microorganisms, and potential full-scale applications is thus of great importance. Here, an overview of the commonly used non-organic electron donors, e.g., hydrogen, reduced sulfur compounds and ferrous ions, in denitrification for treating low C/N ratio wastewater is provided. Also, the feasibility of applying the combined processes based on autotrophic denitrification with the compounds is discussed. Furthermore, challenges and future possibilities as well as concerns about the practical applications are envisaged in this review.
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Affiliation(s)
- Tian Tian
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China.
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28
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Tian T, Zhou K, Xuan L, Zhang JX, Li YS, Liu DF, Yu HQ. Exclusive microbially driven autotrophic iron-dependent denitrification in a reactor inoculated with activated sludge. WATER RESEARCH 2020; 170:115300. [PMID: 31756614 DOI: 10.1016/j.watres.2019.115300] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/06/2019] [Accepted: 11/08/2019] [Indexed: 06/10/2023]
Abstract
Autotrophic iron-dependent denitrification (AIDD) is arising as a promising process for nitrogen removal from wastewater with a low carbon to nitrogen ratio. However, there is still a debate about the existence of such a process in activated sludge systems. This work provides evidence and elucidated the feasibility of autotrophic Fe(II)-oxidizing nitrate-reducing culture for nitrogen removal by long-term reactor operation, batch experimental verification, unstructured kinetic modeling and microbial community analyses. A relatively stable nitrate removal rate was achieved coupled with the oxidation of ferrous ions in 3-month operation of reactor. The kinetic modeling suggests that the iron oxidation was a growth-associated process in AIDD. Utilization of extracellular polymeric substances (and/or soluble microbial products) as electron donor for denitrification by heterotrophic denitrifiers was not mainly responsible for nitrogen removal in the reactor. After long-term operation of the reactor with activated sludge as inoculum, the enrichment culture KS-like consortium, dominated by Fe(II) oxidizer, Gallionellaceae, was successfully acclimated for autotrophic Fe(II)-oxidizing nitrate reduction. This work extents our understanding about the existence of such an autotrophic Fe(II)-oxidizing nitrate-reducing culture in both natural and engineered systems, and opens a door for its potential application in wastewater treatment.
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Affiliation(s)
- Tian Tian
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei, 230026, China
| | - Ke Zhou
- School of Resources & Environmental Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Liang Xuan
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei, 230026, China; School of Environmental Science & Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, 200092, China
| | - Jing-Xiao Zhang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei, 230026, China
| | - Yu-Sheng Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei, 230026, China
| | - Dong-Feng Liu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei, 230026, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei, 230026, China; School of Resources & Environmental Engineering, Hefei University of Technology, Hefei, 230009, China.
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29
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Lin J, He F, Su B, Sun M, Owens G, Chen Z. The stabilizing mechanism of cadmium in contaminated soil using green synthesized iron oxide nanoparticles under long-term incubation. JOURNAL OF HAZARDOUS MATERIALS 2019; 379:120832. [PMID: 31276925 DOI: 10.1016/j.jhazmat.2019.120832] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 04/08/2019] [Accepted: 06/26/2019] [Indexed: 05/02/2023]
Abstract
Despite numerous studies having been conducted on the stabilization of heavy metal contaminated soil, our understanding of the mechanisms involved remains limited. Here green synthesized iron oxide nanoparticles (GION) were applied to stabilize cadmium (Cd) in a contaminated soil. GION not only stabilized soil Cd, but also improved soil properties within one year of incubation. After GION application both the exchangeable and carbonate bound Cd fractions decreased by 14.2-83.5% and 18.3-85.8% respectively, and most of the Cd was translocated to the residual Cd fraction. The application of GION also strongly altered soil bacterial communities. In GION treatments, the abundance of Gemmatimonadetes, Proteobacteria, and Saccharibacteria increased which led to a shift in the dominant bacterial genera from Bacillus to Candidatus koribacter. The variation in bacteria confirmed the restoration of the contaminated soil. The most abundant bacterial genus and species found in GION treatments were related to (i) plant derived biomass decomposition; (ii) ammoxidation and denitrification; and (iii) Fe oxidation. GION application may enhance the formation of larger soil aggregates with anaerobic centers and coprecipitation coupled Fe (II) oxidization, ammoxidation and nitrite reduction followed by Fe mineral ripening may be involved in Cd stabilization. The predominant stabilization mechanism was thus coprecipitation-ripening-stabilization.
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Affiliation(s)
- Jiajiang Lin
- Fujian Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, China
| | - Fengxin He
- Fujian Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, China
| | - Binglin Su
- Fujian Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, China
| | - Mengqiang Sun
- Fujian Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, China
| | - Gary Owens
- Environmental Contaminants Group, Future Industries Institute, University of South Australia, Mawson Lakes, SA, 5095, Australia
| | - Zuliang Chen
- Fujian Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, China; Environmental Contaminants Group, Future Industries Institute, University of South Australia, Mawson Lakes, SA, 5095, Australia.
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30
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Schad M, Konhauser KO, Sánchez-Baracaldo P, Kappler A, Bryce C. How did the evolution of oxygenic photosynthesis influence the temporal and spatial development of the microbial iron cycle on ancient Earth? Free Radic Biol Med 2019; 140:154-166. [PMID: 31323314 DOI: 10.1016/j.freeradbiomed.2019.07.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 07/05/2019] [Accepted: 07/15/2019] [Indexed: 12/22/2022]
Abstract
Iron is the most abundant redox active metal on Earth and thus provides one of the most important records of the redox state of Earth's ancient atmosphere, oceans and landmasses over geological time. The most dramatic shifts in the Earth's iron cycle occurred during the oxidation of Earth's atmosphere. However, tracking the spatial and temporal development of the iron cycle is complicated by uncertainties about both the timing and location of the evolution of oxygenic photosynthesis, and by the myriad of microbial processes that act to cycle iron between redox states. In this review, we piece together the geological evidence to assess where and when oxygenic photosynthesis likely evolved, and attempt to evaluate the influence of this innovation on the microbial iron cycle.
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Affiliation(s)
- Manuel Schad
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, 72076, Tübingen, Germany
| | - Kurt O Konhauser
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | | | - Andreas Kappler
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, 72076, Tübingen, Germany
| | - Casey Bryce
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, 72076, Tübingen, Germany.
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31
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Bryce C, Blackwell N, Schmidt C, Otte J, Huang YM, Kleindienst S, Tomaszewski E, Schad M, Warter V, Peng C, Byrne JM, Kappler A. Microbial anaerobic Fe(II) oxidation - Ecology, mechanisms and environmental implications. Environ Microbiol 2018; 20:3462-3483. [DOI: 10.1111/1462-2920.14328] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 06/15/2018] [Accepted: 06/16/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Casey Bryce
- Geomicrobiology; University of Tübingen; Tübingen Germany
| | - Nia Blackwell
- Geomicrobiology; University of Tübingen; Tübingen Germany
| | | | - Julia Otte
- Geomicrobiology; University of Tübingen; Tübingen Germany
| | - Yu-Ming Huang
- Geomicrobiology; University of Tübingen; Tübingen Germany
| | | | | | - Manuel Schad
- Geomicrobiology; University of Tübingen; Tübingen Germany
| | - Viola Warter
- Geomicrobiology; University of Tübingen; Tübingen Germany
| | - Chao Peng
- Geomicrobiology; University of Tübingen; Tübingen Germany
| | - James M. Byrne
- Geomicrobiology; University of Tübingen; Tübingen Germany
| | - Andreas Kappler
- Geomicrobiology; University of Tübingen; Tübingen Germany
- Center for Geomicrobiology, Department of Bioscience; Aarhus University; Aarhus Denmark
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Singh VK, Singh AL, Singh R, Kumar A. Iron oxidizing bacteria: insights on diversity, mechanism of iron oxidation and role in management of metal pollution. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/s42398-018-0024-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Park S, Lee JH, Shin TJ, Hur HG, Kim MG. Adsorption and Incorporation of Arsenic to Biogenic Lepidocrocite Formed in the Presence of Ferrous Iron during Denitrification by Paracoccus denitrificans. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9983-9991. [PMID: 30111094 DOI: 10.1021/acs.est.8b02101] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We demonstrate adsorption and partial incorporation of arsenic, in its soluble form, either as arsenite or arsenate into lepidocrocite (γ-FeOOH), which was formed through nitrite-driven Fe(II) oxidation by Paracoccus denitrificans under nitrate-reducing conditions. Fe and As K-edge XANES and radial distribution functions of Fourier-transformed EXAFS spectra showed that portions of As were found to be incorporated in the biogenic lepidocrocite, in addition to higher portions of adsorbed As. We suggest that denitrifying bacteria such as Paracoccus denitrificans, studied here, could facilitate decrease of aqueous arsenic As(III) and/or As(V) through indirect Fe(II) oxidation to solid phase iron minerals, here as lepidocrocite, by the denitrification product nitrite in the presence of nitrate, ferrous iron, and arsenic, under certain environmental conditions where these materials could be found, such as in As-contaminated paddy soils and wetlands.
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Affiliation(s)
- Sunhwa Park
- School of Earth Sciences and Environmental Engineering , Gwangju Institute of Science and Technology (GIST) , 123 Cheomdan-gwagiro , Buk-gu, Gwangju 61005 , Republic of Korea
| | - Ji-Hoon Lee
- Department of Bioenvironmental Chemistry , Chonbuk National University , Jeonju 54896 , Republic of Korea
| | - Tae Joo Shin
- UNIST Central Research Facilities & School of Natural Science , Ulsan National Institute of Science and Technology (UNIST) , Ulsan 44919 , Republic of Korea
| | - Hor-Gil Hur
- School of Earth Sciences and Environmental Engineering , Gwangju Institute of Science and Technology (GIST) , 123 Cheomdan-gwagiro , Buk-gu, Gwangju 61005 , Republic of Korea
| | - Min Gyu Kim
- Pohang Accelerator Laboratory (PAL) , Pohang University of Science and Technology , Pohang 37673 , Republic of Korea
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Insights into Carbon Metabolism Provided by Fluorescence In Situ Hybridization-Secondary Ion Mass Spectrometry Imaging of an Autotrophic, Nitrate-Reducing, Fe(II)-Oxidizing Enrichment Culture. Appl Environ Microbiol 2018; 84:AEM.02166-17. [PMID: 29500258 DOI: 10.1128/aem.02166-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 02/20/2018] [Indexed: 01/03/2023] Open
Abstract
The enrichment culture KS is one of the few existing autotrophic, nitrate-reducing, Fe(II)-oxidizing cultures that can be continuously transferred without an organic carbon source. We used a combination of catalyzed amplification reporter deposition fluorescence in situ hybridization (CARD-FISH) and nanoscale secondary ion mass spectrometry (NanoSIMS) to analyze community dynamics, single-cell activities, and interactions among the two most abundant microbial community members (i.e., Gallionellaceae sp. and Bradyrhizobium spp.) under autotrophic and heterotrophic growth conditions. CARD-FISH cell counts showed the dominance of the Fe(II) oxidizer Gallionellaceae sp. under autotrophic conditions as well as of Bradyrhizobium spp. under heterotrophic conditions. We used NanoSIMS to monitor the fate of 13C-labeled bicarbonate and acetate as well as 15N-labeled ammonium at the single-cell level for both taxa. Under autotrophic conditions, only the Gallionellaceae sp. was actively incorporating 13C-labeled bicarbonate and 15N-labeled ammonium. Interestingly, both Bradyrhizobium spp. and Gallionellaceae sp. became enriched in [13C]acetate and [15N]ammonium under heterotrophic conditions. Our experiments demonstrated that Gallionellaceae sp. was capable of assimilating [13C]acetate while Bradyrhizobium spp. were not able to fix CO2, although a metagenomics survey of culture KS recently revealed that Gallionellaceae sp. lacks genes for acetate uptake and that the Bradyrhizobium sp. carries the genetic potential to fix CO2 The study furthermore extends our understanding of the microbial reactions that interlink the nitrogen and Fe cycles in the environment.IMPORTANCE Microbial mechanisms by which Fe(II) is oxidized with nitrate as the terminal electron acceptor are generally referred to as "nitrate-dependent Fe(II) oxidation" (NDFO). NDFO has been demonstrated in laboratory cultures (such as the one studied in this work) and in a variety of marine and freshwater sediments. Recently, the importance of NDFO for the transport of sediment-derived Fe in aquatic ecosystems has been emphasized in a series of studies discussing the impact of NDFO for sedimentary nutrient cycling and redox dynamics in marine and freshwater environments. In this article, we report results from an isotope labeling study performed with the autotrophic, nitrate-reducing, Fe(II)-oxidizing enrichment culture KS, which was first described by Straub et al. (1) about 20 years ago. Our current study builds on the recently published metagenome of culture KS (2).
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