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Margalef-Marti R, Thibault De Chanvalon A, Anschutz P, Amouroux D, Sebilo M. Synergies of chemodenitrification and denitrification in a saline inland lake. CHEMOSPHERE 2024; 359:142292. [PMID: 38729442 DOI: 10.1016/j.chemosphere.2024.142292] [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: 02/25/2024] [Revised: 05/03/2024] [Accepted: 05/07/2024] [Indexed: 05/12/2024]
Abstract
The interconnection between biotic and abiotic pathways involving the nitrogen and iron biogeochemical cycles has recently gained interest. While lacustrine ecosystems are considered prone to the biotic nitrate reduction (denitrification), their potential for promoting the abiotic nitrite reduction (chemodenitrification) remains unclear. In the present study, batch incubations were performed to assess the potential for chemodenitrification and denitrification in the saline inland lake Gallocanta. Sulfidic conditions are found in top sediments of the system while below (5-9 cm), it presents low organic carbon and high sulfate and ferrous iron availability. Anoxic incubations of sediment (5-9 cm) and water from the lake with nitrite revealed potential for chemodenitrification, especially when external ferrous iron was added. The obtained isotopic fractionation values for nitrite (ɛ15NNO2) were -6.8 and -12.3 ‰ and therefore, fell in the range of those previously reported for the nitrite reduction. The more pronounced ɛ15NNO2 (-12.3 ‰) measured in the experiment containing additional ferrous iron was attributed to a higher contribution of the chemodenitrification over biotic denitrification. Incubations containing nitrate also confirmed the potential for denitrification under autotrophic conditions (low organic carbon, high ferrous iron). Higher reaction rate constants were found in the experiment containing 100 μM compared to 400 μM nitrate. The obtained ɛ15NNO3 values (-8.5 and -15.1 ‰) during nitrate consumption fell in the range of those expected for the denitrification. A more pronounced ɛ15NNO3 (-15.1 ‰) was determined in the experiment presenting a lower reaction rate constant (400 μM nitrate). Therefore, in Gallocanta lake, nitrite generated during nitrate reduction can be further reduced by both the abiotic and biotic pathways. These findings establish the significance of chemodenitrification in lacustrine systems and support further exploration in aquatic environments with different levels of C, N, S, and Fe. This might be especially useful in predicting nitrous oxide emissions in natural ecosystems.
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Affiliation(s)
- Rosanna Margalef-Marti
- Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les Matériaux (IPREM), Pau, France; Grup MAiMA, MAGH, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de La Terra, Universitat de Barcelona (UB), 08028, Barcelona, Spain.
| | - Aubin Thibault De Chanvalon
- Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les Matériaux (IPREM), Pau, France
| | - Pierre Anschutz
- Univ. Bordeaux, CNRS, Bordeaux INP, EPOC, UMR 5805, F-33600, Pessac, France
| | - David Amouroux
- Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les Matériaux (IPREM), Pau, France
| | - Mathieu Sebilo
- Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les Matériaux (IPREM), Pau, France; Sorbonne Université, CNRS, IEES, Paris, France
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Pan D, Chen P, Yang G, Niu R, Bai Y, Cheng K, Huang G, Liu T, Li X, Li F. Fe(II) Oxidation Shaped Functional Genes and Bacteria Involved in Denitrification and Dissimilatory Nitrate Reduction to Ammonium from Different Paddy Soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:21156-21167. [PMID: 38064275 DOI: 10.1021/acs.est.3c06337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
Microbial nitrate reduction can drive Fe(II) oxidation in anoxic environments, affecting the nitrous oxide emission and ammonium availability. The nitrate-reducing Fe(II) oxidation usually causes severe cell encrustation via chemodenitrification and potentially inhibits bacterial activity due to the blocking effect of secondary minerals. However, it remains unclear how Fe(II) oxidation and subsequent cell encrustation affect the functional genes and bacteria for denitrification and dissimilatory nitrate reduction to ammonium (DNRA). Here, bacteria were enriched from different paddy soils with and without Fe(II) under nitrate-reducing conditions. Fe(II) addition decelerated nitrate reduction and increased NO2- accumulation, due to the rapid Fe(II) oxidation and cell encrustation in the periplasm and on the cell surface. The N2O accumulation was lower in the treatment with Fe(II) and nitrate than that in the treatment with nitrate only, although the proportions of N2O and NH4+ to the reduced NO3- were low (3.25% ∼ 6.51%) at the end of incubation regardless of Fe(II) addition. The dominant bacteria varied from soils under nitrate-reducing conditions, while Fe(II) addition shaped a similar microbial community, including Dechloromonas, Azospira, and Pseudomonas. Fe(II) addition increased the relative abundance of napAB, nirS, norBC, nosZ, and nirBD genes but decreased that of narG and nrfA, suggesting that Fe(II) oxidation favored denitrification in the periplasm and NO2--to-NH4+ reduction in the cytoplasm. Dechloromonas dominated the NO2--to-N2O reduction, while Thauera mediated the periplasmic nitrate reduction and cytoplasmic NO2--to-NH4+ during Fe(II) oxidation. However, Thauera showed much lower abundance than the dominant genera, resulting in slow nitrate reduction and limited NH4+ production. These findings provide new insights into the response of denitrification and DNRA bacteria to Fe(II) oxidation and cell encrustation in anoxic environments.
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Affiliation(s)
- Dandan Pan
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Provincial Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
- School of Environment, South China Normal University, Guangzhou 510006, China
| | - Pengcheng Chen
- School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Guang Yang
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
- School of Environment, South China Normal University, Guangzhou 510006, China
| | - Rumiao Niu
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
- School of Environment, South China Normal University, Guangzhou 510006, China
| | - Yan Bai
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Provincial Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
- School of Environment, South China Normal University, Guangzhou 510006, China
| | - Kuan Cheng
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Provincial Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Guoyong Huang
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Provincial Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
- School of Environment, South China Normal University, Guangzhou 510006, China
| | - Tongxu Liu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Provincial Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Xiaomin Li
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
- School of Environment, South China Normal University, Guangzhou 510006, China
| | - Fangbai Li
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Provincial Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
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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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Shewanella sp. T2.3D-1.1 a Novel Microorganism Sustaining the Iron Cycle in the Deep Subsurface of the Iberian Pyrite Belt. Microorganisms 2022; 10:microorganisms10081585. [PMID: 36014003 PMCID: PMC9415397 DOI: 10.3390/microorganisms10081585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 07/29/2022] [Accepted: 08/03/2022] [Indexed: 11/16/2022] Open
Abstract
The Iberian Pyrite Belt (IPB) is one of the largest deposits of sulphidic minerals on Earth. Río Tinto raises from its core, presenting low a pH and high metal concentration. Several drilling cores were extracted from the IPB’s subsurface, and strain T2.3D-1.1 was isolated from a core at 121.8 m depth. We aimed to characterize this subterranean microorganism, revealing its phylogenomic affiliation (Average Nucleotide Identity, digital DNA-DNA Hybridization) and inferring its physiology through genome annotation, backed with physiological experiments to explore its relationship with the Fe biogeochemical cycle. Results determined that the isolate belongs to the Shewanella putrefaciens (with ANI 99.25 with S. putrefaciens CN-32). Its genome harbours the necessary genes, including omcA mtrCAB, to perform the Extracellular Electron Transfer (EET) and reduce acceptors such as Fe3+, napAB to reduce NO3− to NO2−, hydAB to produce H2 and genes sirA, phsABC and ttrABC to reduce SO32−, S2O32− and S4O62−, respectively. A full CRISPR-Cas 1F type system was found as well. S. putrefaciens T2.3D-1.1 can reduce Fe3+ and promote the oxidation of Fe2+ in the presence of NO3− under anaerobic conditions. Production of H2 has been observed under anaerobic conditions with lactate or pyruvate as the electron donor and fumarate as the electron acceptor. Besides Fe3+ and NO3−, the isolate also grows with Dimethyl Sulfoxide and Trimethyl N-oxide, S4O62− and S2O32− as electron acceptors. It tolerates different concentrations of heavy metals such as 7.5 mM of Pb, 5 mM of Cr and Cu and 1 mM of Cd, Co, Ni and Zn. This array of traits suggests that S. putrefaciens T2.3D-1.1 could have an important role within the Iberian Pyrite Belt subsurface participating in the iron cycle, through the dissolution of iron minerals and therefore contributing to generate the extreme conditions detected in the Río Tinto basin.
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Dopffel N, Jamieson J, Bryce C, Joshi P, Mansor M, Siade A, Prommer H, Kappler A. Temperature dependence of nitrate-reducing Fe(II) oxidation by Acidovorax strain BoFeN1 - evaluating the role of enzymatic vs. abiotic Fe(II) oxidation by nitrite. FEMS Microbiol Ecol 2021; 97:6442174. [PMID: 34849752 DOI: 10.1093/femsec/fiab155] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 11/24/2021] [Indexed: 11/14/2022] Open
Abstract
Fe(II) oxidation coupled to nitrate reduction is a widely observed metabolism. However, to what extent the observed Fe(II) oxidation is driven enzymatically or abiotically by metabolically produced nitrite remains puzzling. To distinguish between biotic and abiotic reactions, we cultivated the mixotrophic nitrate-reducing Fe(II)-oxidizing Acidovorax strain BoFeN1 over a wide range of temperatures and compared it to abiotic Fe(II) oxidation by nitrite at temperatures up to 60°C. The collected experimental data were subsequently analyzed through biogeochemical modeling. At 5°C, BoFeN1 cultures consumed acetate and reduced nitrate but did not significantly oxidize Fe(II). Abiotic Fe(II) oxidation by nitrite at different temperatures showed an Arrhenius-type behavior with an activation energy of 80±7 kJ/mol. Above 40°C, the kinetics of Fe(II) oxidation were abiotically driven, whereas at 30°C, where BoFeN1 can actively metabolize, the model-based interpretation strongly suggested that an enzymatic pathway was responsible for a large fraction (ca. 62%) of the oxidation. This result was reproduced even when no additional carbon source was present. Our results show that at below 30°C, i.e., at temperatures representing most natural environments, biological Fe(II) oxidation was largely responsible for overall Fe(II) oxidation, while abiotic Fe(II) oxidation by nitrite played a less important role.
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Affiliation(s)
- Nicole Dopffel
- Norwegian Research Center - NORCE, 22 Nygårdstangen, 5838 Bergen, Norway
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, 72074 Tübingen, Germany
| | - James Jamieson
- School of Earth Sciences, University of Western Australia, 35 Stirling Highway, 6009 Crawley, Australia
- CSIRO Land and Water, 147 Underwood Avenue, 6014 Floreat, Australia
| | - Casey Bryce
- School of Earth Sciences, University of Bristol, Queens Road, Bristol BS8 1RJ, United Kingdom
| | - Prachi Joshi
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, 72074 Tübingen, Germany
| | - Muammar Mansor
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, 72074 Tübingen, Germany
| | - Adam Siade
- School of Earth Sciences, University of Western Australia, 35 Stirling Highway, 6009 Crawley, Australia
- CSIRO Land and Water, 147 Underwood Avenue, 6014 Floreat, Australia
| | - Henning Prommer
- School of Earth Sciences, University of Western Australia, 35 Stirling Highway, 6009 Crawley, Australia
- CSIRO Land and Water, 147 Underwood Avenue, 6014 Floreat, Australia
| | - Andreas Kappler
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, 72074 Tübingen, Germany
- Cluster of Excellence EXC 2124: Controlling Microbes to Fight Infection, University of Tubingen, 72074 Tübingen, Germany
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Huang J, Franklin H, Teasdale PR, Burford MA, Kankanamge NR, Bennett WW, Welsh DT. Comparison of DET, DGT and conventional porewater extractions for determining nutrient profiles and cycling in stream sediments. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:2128-2140. [PMID: 31681920 DOI: 10.1039/c9em00312f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Determining inorganic nutrient profiles to support understanding of nitrogen transformations in stream sediments is challenging, due to nitrification and denitrification being confined to particular conditions in potentially heterogeneous sediment influenced by benthic microalgae, rooted aquatic plants and/or diel light cycles. The diffusive gradients in thin films (DGT) and diffusive equilibration in thin films (DET) techniques allow in situ determination of porewater concentration profiles, and distributions for some solutes. In this study, DGT, DET and conventional porewater extraction (sectioning and centrifugation) methods were compared for ammonium and nitrate in stream sediments under light and dark conditions. Two-dimensional distributions of Fe(ii) and PO4-P were also provided to indicate the degree of spatial and temporal heterogeneity in sediment porewater, which can explain the sources and sinks of ammonium at various depths in the sediments. Although the conventional porewater extraction method consistently measured higher NH4-N concentrations than the DGT and DET techniques, the study showed that the DET measurements were the most reliable indicator of porewater NH4-N concentrations, with the DGT data being usefully supplementary. However, a large proportion of the NO3-N concentrations measured by DGT and DET were close to or below the method detection limits. Therefore, further development of these techniques is required to reduce the blanks and detection limits to allow natural low sediment porewater NO3-N concentrations to be accurately monitored using DGT and DET. The study indicated that benthic microalgae had direct and indirect influences on porewater nutrient distributions over light-dark cycles. Overall, DGT and DET techniques can be useful for monitoring porewater nutrient concentrations and profiles and for determining how biological processes drive changes in sediment nutrient concentrations and distributions.
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Affiliation(s)
- Jianyin Huang
- Natural and Built Environments Research Centre, School of Natural and Built Environments, University of South Australia, SA 5095, Australia.
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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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Iron Redox Reactions Can Drive Microtopographic Variation in Upland Soil Carbon Dioxide and Nitrous Oxide Emissions. SOIL SYSTEMS 2019. [DOI: 10.3390/soilsystems3030060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Topographic depressions in upland soils experience anaerobic conditions conducive for iron (Fe) reduction following heavy rainfall. These depressional areas can also accumulate reactive Fe compounds, carbon (C), and nitrate, creating potential hot spots of Fe-mediated carbon dioxide (CO2) and nitrous oxide (N2O) production. While there are multiple mechanisms by which Fe redox reactions can facilitate CO2 and N2O production, it is unclear what their cumulative effect is on CO2 and N2O emissions in depressional soils under dynamic redox. We hypothesized that Fe reduction and oxidation facilitate greater CO2 and N2O emissions in depressional compared to upslope soils in response to flooding. To test this, we amended upslope and depressional soils with Fe(II), Fe(III), or labile C and measured CO2 and N2O emissions in response to flooding. We found that depressional soils have greater Fe reduction potential, which can contribute to soil CO2 emissions during flooded conditions when C is not limiting. Additionally, Fe(II) addition stimulated N2O production, suggesting that chemodenitrification may be an important pathway of N2O production in depressions that accumulate Fe(II). As rainfall intensification results in more frequent flooding of depressional upland soils, Fe-mediated CO2 and N2O production may become increasingly important pathways of soil greenhouse gas emissions.
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Bennett BD, Gralnick JA. Mechanisms of toxicity by and resistance to ferrous iron in anaerobic systems. Free Radic Biol Med 2019; 140:167-171. [PMID: 31251977 DOI: 10.1016/j.freeradbiomed.2019.06.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 06/13/2019] [Accepted: 06/23/2019] [Indexed: 12/24/2022]
Abstract
Iron is an essential element for nearly all life on Earth, primarily for its value as a redox active cofactor. Iron exists predominantly in two biologically relevant redox states: ferric iron, the oxidized state (Fe3+), and ferrous iron, the reduced state (Fe2+). Fe2+ is well known to facilitate electron transfer reactions that can lead to the generation of reactive oxygen species. Less is known about why iron is toxic to cells in the absence of oxygen, yet this phenomenon is critically important for our understanding of life on early Earth and in iron-rich ecosystems today. In this brief review, we will highlight our current understanding of anaerobic Fe2+ toxicity, focusing on molecular mechanistic studies in several model systems.
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Affiliation(s)
- B D Bennett
- Pacific Biosciences Research Center, University of Hawai‛i at Mānoa, Honolulu, HI, 96813, USA
| | - J A Gralnick
- BioTechnology Institute and Department of Plant and Microbial Biology, University of Minnesota - Twin Cities, St. Paul, MN, 55108, USA.
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Zhou GW, Yang XR, Rønn R, Su JQ, Cui L, Zheng BX, Zhu YG. Metabolic Inactivity and Re-awakening of a Nitrate Reduction Dependent Iron(II)-Oxidizing Bacterium Bacillus ferrooxidans. Front Microbiol 2019; 10:1494. [PMID: 31333611 PMCID: PMC6617468 DOI: 10.3389/fmicb.2019.01494] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 06/14/2019] [Indexed: 11/13/2022] Open
Abstract
Microorganisms capable of anaerobic nitrate-dependent Fe(II) (ferrous iron) oxidation (ANDFO) contribute significantly to iron and nitrogen cycling in various environments. However, lab efforts in continuous cultivation of ANDFO strains suffer from loss of activity when ferrous iron is used as sole electron donor. Here, we used a novel strain of nitrate-dependent Fe(II)-oxidizing bacterium Bacillus ferroxidians as a model and focused on the physiological activity of cells during ANDFO. It was shown that B. ferrooxidans entered a metabolically inactive state during ANDFO. B. ferrooxidans exhibited nitrate reduction coupled with Fe(II) oxidation, and the activity gradually declined and was hardly detected after 48-h incubation. Propidium monoazide (PMA) assisted 16S rRNA gene real-time PCR suggested that a large number of B. ferrooxidans cells were alive during incubation. However, 2H(D)-isotope based Raman analysis indicated that the cells were metabolically inactive after 120-h of ANDFO. These inactive cells re-awakened in R2A medium and were capable of growth and reproduction, which was consistent with results in Raman analysis. Scanning electron microscopy (SEM) observation and x-ray diffraction (XRD) revealed the formation of Fe minerals in close proximity of cells in the Fe(II)-oxidizing medium after Fe(II) oxidation. Overall, our results demonstrated that continued ANDFO can induce a metabolically inactive state in B. ferrooxidans, which was responsible for the loss of activity during ANDFO. This study provides an insight into the ANDFO process and its contribution to iron and nitrogen cycling in the environments.
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Affiliation(s)
- Guo-Wei Zhou
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.,State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Xiao-Ru Yang
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Regin Rønn
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jian-Qiang Su
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Li Cui
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Bang-Xiao Zheng
- Faculty of Biological and Environmental Sciences, University of Helsinki, Lahti, Finland
| | - Yong-Guan Zhu
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.,State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
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11
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Cheng S, Li N, Jiang L, Li Y, Xu B, Zhou W. Biodegradation of metal complex Naphthol Green B and formation of iron-sulfur nanoparticles by marine bacterium Pseudoalteromonas sp CF10-13. BIORESOURCE TECHNOLOGY 2019; 273:49-55. [PMID: 30408643 DOI: 10.1016/j.biortech.2018.10.082] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/28/2018] [Accepted: 10/29/2018] [Indexed: 06/08/2023]
Abstract
Treatment of metal complex dye wastewater has attracted growing attention due to the degradation-resistant, high cost and potential hazards of current techniques. This study reported a marine bacterium (Pseudoalteromonas sp CF10-13) with potential performance in decolorization and degradation of a metal complex dye-Naphthol Green B (NGB) at wide ranges of salinity, dye concentration and alkalinity under anaerobic conditions. It was inferred that the secretion of electron mediators in soluble extracellular metabolites by P. sp CF10-13 played important roles in NGB decolorization and degradation through extracellular electron transfer. Naphthalenesulfonate, the major structure in NGB molecule, was further degraded into low-toxic benzamide. Black stable iron-sulfur nanoparticles were formed endogenously avoiding H2S releasing, exogenous sulfur addition and metal sludge in accumulation. Accordingly, this study provided a cost-effective and eco-friendly biodegradation method to refractory NGB, further promoting the understanding of dye resources recovery.
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Affiliation(s)
- Shuhua Cheng
- School of Environmental Science and Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Na Li
- School of Environmental Science and Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Li Jiang
- School of Environmental Science and Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Yating Li
- School of Environmental Science and Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Baiheng Xu
- School of Environmental Science and Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Weizhi Zhou
- School of Environmental Science and Engineering, Shandong University, Jinan, Shandong 250100, China.
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12
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Stanton CL, Reinhard CT, Kasting JF, Ostrom NE, Haslun JA, Lyons TW, Glass JB. Nitrous oxide from chemodenitrification: A possible missing link in the Proterozoic greenhouse and the evolution of aerobic respiration. GEOBIOLOGY 2018; 16:597-609. [PMID: 30133143 DOI: 10.1111/gbi.12311] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/23/2018] [Accepted: 07/02/2018] [Indexed: 05/26/2023]
Abstract
The potent greenhouse gas nitrous oxide (N2 O) may have been an important constituent of Earth's atmosphere during Proterozoic (~2.5-0.5 Ga). Here, we tested the hypothesis that chemodenitrification, the rapid reduction of nitric oxide by ferrous iron, would have enhanced the flux of N2 O from ferruginous Proterozoic seas. We empirically derived a rate law, d N 2 O d t = 7.2 × 10 - 5 [ Fe 2 + ] 0.3 [ NO ] 1 , and measured an isotopic site preference of +16‰ for the reaction. Using this empirical rate law, and integrating across an oceanwide oxycline, we found that low nM NO and μM-low mM Fe2+ concentrations could have sustained a sea-air flux of 100-200 Tg N2 O-N year-1 , if N2 fixation rates were near-modern and all fixed N2 was emitted as N2 O. A 1D photochemical model was used to obtain steady-state atmospheric N2 O concentrations as a function of sea-air N2 O flux across the wide range of possible pO2 values (0.001-1 PAL). At 100-200 Tg N2 O-N year-1 and >0.1 PAL O2 , this model yielded low-ppmv N2 O, which would produce several degrees of greenhouse warming at 1.6 ppmv CH4 and 320 ppmv CO2 . These results suggest that enhanced N2 O production in ferruginous seawater via a previously unconsidered chemodenitrification pathway may have helped to fill a Proterozoic "greenhouse gap," reconciling an ice-free Mesoproterozoic Earth with a less luminous early Sun. A particularly notable result was that high N2 O fluxes at intermediate O2 concentrations (0.01-0.1 PAL) would have enhanced ozone screening of solar UV radiation. Due to rapid photolysis in the absence of an ozone shield, N2 O is unlikely to have been an important greenhouse gas if Mesoproterozoic O2 was 0.001 PAL. At low O2 , N2 O might have played a more important role as life's primary terminal electron acceptor during the transition from an anoxic to oxic surface Earth, and correspondingly, from anaerobic to aerobic metabolisms.
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Affiliation(s)
- Chloe L Stanton
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia
- Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania
| | - Christopher T Reinhard
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - James F Kasting
- Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania
| | - Nathaniel E Ostrom
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan
- DOE Great Lakes Bioenergy Research Institute, Michigan State University, East Lansing, Michigan
| | - Joshua A Haslun
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan
| | - Timothy W Lyons
- Department of Earth Sciences, University of California, Riverside, California
| | - Jennifer B Glass
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia
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13
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Kiilerich B, Kiilerich P, Nielsen AH, Vollertsen J. Variations in activities of sewer biofilms due to ferrous and ferric iron dosing. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2018; 2017:845-858. [PMID: 30016302 DOI: 10.2166/wst.2018.261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Addition of ferrous and ferric iron salts to wastewater is a commonly used practice for sulfide abatement in sewer force mains. When iron is added to wastewater where sulfate respiration takes place, it produces ferrous sulfide precipitates with the formed sulfide. The effect of iron addition has traditionally been focused on solely from the perspective of reaction stoichiometry. Possible influences on the microbial communities in biofilms growing in force mains have largely been neglected. In this study the activity and microbiome was examined in three pilot scale force mains conveying real wastewater, two subjected to iron treatment and one operated as an untreated control. Activity was measured on suspended biofilm samples extracted from the experimental setup. The microbiome of the biofilm was analyzed by V3 + V4 16S rDNA sequencing. Correlation analysis of chemical composition of the biofilms and activity measurements for operational taxonomic units of relevance to sulfide and methane production were performed. In conclusion, it was found that both ferrous and ferric treatment reduced sulfate reduction and methane production, and that both iron salts induced significant changes to force main biofilm microbiomes.
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Affiliation(s)
- Bruno Kiilerich
- Department of Civil Engineering, Aalborg University, Thomas Manns Vej 23, DK-9220 Aalborg Ø, Denmark E-mail: ; Grundfos Holding A/S, Poul Due Jensens Vej 7, DK-8850 Bjerringbro, Denmark
| | - Pia Kiilerich
- Statens Serum Institut, Artillerivej 5, DK-2300 København S, Denmark
| | - Asbjørn H Nielsen
- Department of Civil Engineering, Aalborg University, Thomas Manns Vej 23, DK-9220 Aalborg Ø, Denmark E-mail:
| | - Jes Vollertsen
- Department of Civil Engineering, Aalborg University, Thomas Manns Vej 23, DK-9220 Aalborg Ø, Denmark E-mail:
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14
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Microbially Mediated Coupling of Fe and N Cycles by Nitrate-Reducing Fe(II)-Oxidizing Bacteria in Littoral Freshwater Sediments. Appl Environ Microbiol 2018; 84:AEM.02013-17. [PMID: 29101195 DOI: 10.1128/aem.02013-17] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 10/31/2017] [Indexed: 11/20/2022] Open
Abstract
Nitrate-reducing iron(II)-oxidizing bacteria have been known for approximately 20 years. There has been much debate as to what extent the reduction of nitrate and the oxidation of ferrous iron are coupled via enzymatic pathways or via abiotic processes induced by nitrite formed by heterotrophic denitrification. The aim of the present study was to assess the coupling of nitrate reduction and iron(II) oxidation by monitoring changes in substrate concentrations, as well as in the activity of nitrate-reducing bacteria in natural littoral freshwater sediment, in response to stimulation with nitrate and iron(II). In substrate-amended microcosms, we found that the biotic oxidation of ferrous iron depended on the simultaneous microbial reduction of nitrate. Additionally, the abiotic oxidation of ferrous iron by nitrite in sterilized sediment was not fast enough to explain the iron oxidation rates observed in microbially active sediment. Furthermore, the expression levels of genes coding for enzymes crucial for nitrate reduction were in some setups stimulated by the presence of ferrous iron. These results indicate that there is a direct influence of ferrous iron on bacterial denitrification and support the hypothesis that microbial nitrate reduction is stimulated by biotic iron(II) oxidation.IMPORTANCE The coupling of nitrate reduction and Fe(II) oxidation affects the environment at a local scale, e.g., by changing nutrient or heavy metal mobility in soils due to the formation of Fe(III) minerals, as well as at a global scale, e.g., by the formation of the primary greenhouse gas nitrous oxide. Although the coupling of nitrate reduction and Fe(II) oxidation was reported 20 years ago and has been studied intensively since then, the underlying mechanisms still remain unknown. One of the main knowledge gaps is the extent of enzymatic Fe(II) oxidation coupled to nitrate reduction, which has frequently been questioned in the literature. In the present study, we provide evidence for microbially mediated nitrate-reducing Fe(II) oxidation in freshwater sediments. This evidence is based on the rates of nitrate reduction and Fe(II) oxidation determined in microcosm incubations and on the effect of iron on the expression of genes required for denitrification.
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15
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Weisener C, Lee J, Chaganti SR, Reid T, Falk N, Drouillard K. Investigating sources and sinks of N 2O expression from freshwater microbial communities in urban watershed sediments. CHEMOSPHERE 2017; 188:697-705. [PMID: 28934707 DOI: 10.1016/j.chemosphere.2017.09.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/06/2017] [Accepted: 09/09/2017] [Indexed: 06/07/2023]
Abstract
Wastewater treatment plants (WWTPs) serve as point-source inputs for a variety of nutrients often dominated by nitrogenous compounds as a result of anthropogenic influence. These effluents can impact biogeochemical cycles in freshwater estuaries, influencing microbial communities in both the water and sediment compartments. To assess the impact of point source nutrients, a transect of sediment and pore water samples were collected from 4 locations in the Little River Sub-watershed including locations above and below the Little River Pollution Control Plant (LRPCP). Variation in chemistry and microbial community/gene expression revealed significant influences of the effluent discharge on the adjacent sediments. Phosphorus and sulfur showed high concentrations within plume sediments compared to the reference sediments while nitrate concentrations were low. Increased abundance of denitrifiers Dechloromonas, Dok59 and Thermomonas correlating with increased expression of nitrous-oxide reductase suggests a conversion of N2O to N2 within the LRPCP effluent sediments. This study provides valuable insight into the gene regulation of microbes involved in N metabolism (denitrification, nitrification, and nitrite reduction to ammonia) within the sediment compartment influenced by wastewater effluent.
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Affiliation(s)
- Christopher Weisener
- Great Lakes Institute for Environmental Science, University of Windsor, 401 Sunset Avenue, Windsor, Ontario, N9B 3P4, Canada.
| | - Jumin Lee
- Great Lakes Institute for Environmental Science, University of Windsor, 401 Sunset Avenue, Windsor, Ontario, N9B 3P4, Canada; Earth Science Department, Western University, London, Ontario, Canada
| | - Subba Rao Chaganti
- Great Lakes Institute for Environmental Science, University of Windsor, 401 Sunset Avenue, Windsor, Ontario, N9B 3P4, Canada
| | - Thomas Reid
- Great Lakes Institute for Environmental Science, University of Windsor, 401 Sunset Avenue, Windsor, Ontario, N9B 3P4, Canada
| | - Nick Falk
- Great Lakes Institute for Environmental Science, University of Windsor, 401 Sunset Avenue, Windsor, Ontario, N9B 3P4, Canada
| | - Ken Drouillard
- Great Lakes Institute for Environmental Science, University of Windsor, 401 Sunset Avenue, Windsor, Ontario, N9B 3P4, Canada
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16
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Genomics and Ecology of Novel N 2O-Reducing Microorganisms. Trends Microbiol 2017; 26:43-55. [PMID: 28803698 DOI: 10.1016/j.tim.2017.07.003] [Citation(s) in RCA: 205] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 06/29/2017] [Accepted: 07/14/2017] [Indexed: 11/22/2022]
Abstract
Microorganisms with the capacity to reduce the greenhouse gas nitrous oxide (N2O) to harmless dinitrogen gas are receiving increased attention due to increasing N2O emissions (and our need to mitigate climate change) and to recent discoveries of novel N2O-reducing bacteria and archaea. The diversity of denitrifying and nondenitrifying microorganisms with capacity for N2O reduction was recently shown to be greater than previously expected. A formerly overlooked group (clade II) in the environment include a large fraction of nondenitrifying N2O reducers, which could be N2O sinks without major contribution to N2O formation. We review the recent advances about fundamental understanding of the genomics, physiology, and ecology of N2O reducers and the importance of these findings for curbing N2O emissions.
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17
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Heim C, Quéric NV, Ionescu D, Schäfer N, Reitner J. Frutexites-like structures formed by iron oxidizing biofilms in the continental subsurface (Äspö Hard Rock Laboratory, Sweden). PLoS One 2017; 12:e0177542. [PMID: 28542238 PMCID: PMC5438144 DOI: 10.1371/journal.pone.0177542] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 04/29/2017] [Indexed: 11/24/2022] Open
Abstract
Stromatolitic iron-rich structures have been reported from many ancient environments and are often described as Frutexites, a cryptic microfossil. Although microbial formation of such structures is likely, a clear relation to a microbial precursor is lacking so far. Here we report recent iron oxidizing biofilms which resemble the ancient Frutexites structures. The living Frutexites-like biofilms were sampled at 160 m depth in the Äspö Hard Rock Laboratory in Sweden. Investigations using microscopy, 454 pyrosequencing, FISH, Raman spectroscopy, biomarker and trace element analysis allowed a detailed view of the structural components of the mineralized biofilm. The most abundant bacterial groups were involved in nitrogen and iron cycling. Furthermore, Archaea are widely distributed in the Frutexites-like biofilm, even though their functional role remains unclear. Biomarker analysis revealed abundant sterols in the biofilm most likely from algal and fungal origins. Our results indicate that the Frutexites-like biofilm was built up by a complex microbial community. The functional role of each community member in the formation of the dendritic structures, as well as their potential relation to fossil Frutexites remains under investigation.
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Affiliation(s)
- Christine Heim
- Department of Geobiology, Geoscience Centre, University of Göttingen, Göttingen, Germany
| | - Nadia-Valérie Quéric
- Department of Geobiology, Geoscience Centre, University of Göttingen, Göttingen, Germany
| | - Danny Ionescu
- Leibnitz Institute for Freshwater Ecology and Inland Fisheries, IGB, Experimental Limnology, Stechlin, Germany
| | - Nadine Schäfer
- Department of Geobiology, Geoscience Centre, University of Göttingen, Göttingen, Germany
| | - Joachim Reitner
- Department of Geobiology, Geoscience Centre, University of Göttingen, Göttingen, Germany
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18
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Jia W, Wang Q, Zhang J, Yang W, Zhou X. Nutrients removal and nitrous oxide emission during simultaneous nitrification, denitrification, and phosphorus removal process: effect of iron. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:15657-15664. [PMID: 27137189 DOI: 10.1007/s11356-016-6758-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 04/25/2016] [Indexed: 06/05/2023]
Abstract
The short- and long-term influences of ferric iron (Fe(III)) on nutrients removal and nitrous oxide (N2O) emission during SNDPR process were evaluated. According to the continuous cycle experiments, it was concluded that the addition of Fe(III) could lower the nitrogen removal of the following cycle during SNDPR process, which was mainly induced by the chemical removal of phosphorus. However, the impacts were transitory, and simultaneous nitrogen and phosphorus removal would recover from the inhibition of Fe(III) after running certain cycles. Moreover, the addition of Fe(III) could stimulate N2O emission transitorily during SNDPR process. However, if Fe(III) was added into reactor continuously, the nitrogen removal would be improved, especially at low Fe load condition. It was because that the activity of NO reductase was enhanced by the addition of Fe. However, the low Fe load in reactor would induce more N2O emission. When Fe(III) load was 40 mg/L in the reactor, the N2O yield was 10 % higher than control. The TN removal was weakened when Fe(III) load reached to 60 mg/L, and the N2O yield was lower than control, due to the inhibition of the high Fe load on denitrification enzymes.
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Affiliation(s)
- Wenlin Jia
- School of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou, 221116, China.
| | - Qian Wang
- School of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou, 221116, China
| | - Jian Zhang
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Weihua Yang
- School of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou, 221116, China
| | - Xiaowei Zhou
- School of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou, 221116, China
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19
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Zhou J, Wang H, Yang K, Ji B, Chen D, Zhang H, Sun Y, Tian J. Autotrophic denitrification by nitrate-dependent Fe(II) oxidation in a continuous up-flow biofilter. Bioprocess Biosyst Eng 2015; 39:277-84. [DOI: 10.1007/s00449-015-1511-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 11/18/2015] [Indexed: 10/22/2022]
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20
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Scharko NK, Schütte UME, Berke AE, Banina L, Peel HR, Donaldson MA, Hemmerich C, White JR, Raff JD. Combined Flux Chamber and Genomics Approach Links Nitrous Acid Emissions to Ammonia Oxidizing Bacteria and Archaea in Urban and Agricultural Soil. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:13825-34. [PMID: 26248160 DOI: 10.1021/acs.est.5b00838] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Nitrous acid (HONO) is a photochemical source of hydroxyl radical and nitric oxide in the atmosphere that stems from abiotic and biogenic processes, including the activity of ammonia-oxidizing soil microbes. HONO fluxes were measured from agricultural and urban soil in mesocosm studies aimed at characterizing biogenic sources and linking them to indigenous microbial consortia. Fluxes of HONO from agricultural and urban soil were suppressed by addition of a nitrification inhibitor and enhanced by amendment with ammonium (NH4(+)), with peaks at 19 and 8 ng m(-2) s(-1), respectively. In addition, both agricultural and urban soils were observed to convert (15)NH4(+) to HO(15)NO. Genomic surveys of soil samples revealed that 1.5-6% of total expressed 16S rRNA sequences detected belonged to known ammonia oxidizing bacteria and archaea. Peak fluxes of HONO were directly related to the abundance of ammonia-oxidizer sequences, which in turn depended on soil pH. Peak HONO fluxes under fertilized conditions are comparable in magnitude to fluxes reported during field campaigns. The results suggest that biogenic HONO emissions will be important in soil environments that exhibit high nitrification rates (e.g., agricultural soil) although the widespread occurrence of ammonia oxidizers implies that biogenic HONO emissions are also possible in the urban and remote environment.
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Affiliation(s)
- Nicole K Scharko
- School of Public and Environmental Affairs, Indiana University , Bloomington, Indiana 47405-2204, United States
| | - Ursel M E Schütte
- Integrated Program in the Environment, Indiana University , Bloomington, Indiana 47405-2204, United States
| | - Andrew E Berke
- School of Public and Environmental Affairs, Indiana University , Bloomington, Indiana 47405-2204, United States
| | - Lauren Banina
- School of Public and Environmental Affairs, Indiana University , Bloomington, Indiana 47405-2204, United States
| | - Hannah R Peel
- School of Public and Environmental Affairs, Indiana University , Bloomington, Indiana 47405-2204, United States
| | - Melissa A Donaldson
- School of Public and Environmental Affairs, Indiana University , Bloomington, Indiana 47405-2204, United States
| | - Chris Hemmerich
- Center for Genomics and Bioinformatics, Indiana University , Bloomington, Indiana 47405-7005, United States
| | - Jeffrey R White
- School of Public and Environmental Affairs, Indiana University , Bloomington, Indiana 47405-2204, United States
- Integrated Program in the Environment, Indiana University , Bloomington, Indiana 47405-2204, United States
| | - Jonathan D Raff
- School of Public and Environmental Affairs, Indiana University , Bloomington, Indiana 47405-2204, United States
- Department of Chemistry, Indiana University , Bloomington, Indiana 47405-7102, United States
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21
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Li BB, Cheng YY, Wu C, Li WW, Yang ZC, Yu HQ. Interaction between ferrihydrite and nitrate respirations by Shewanella oneidensis MR-1. Process Biochem 2015. [DOI: 10.1016/j.procbio.2015.07.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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22
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Klueglein N, Picardal F, Zedda M, Zwiener C, Kappler A. Oxidation of Fe(II)-EDTA by nitrite and by two nitrate-reducing Fe(II)-oxidizing Acidovorax strains. GEOBIOLOGY 2015; 13:198-207. [PMID: 25612223 DOI: 10.1111/gbi.12125] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 12/29/2014] [Indexed: 06/04/2023]
Abstract
The enzymatic oxidation of Fe(II) by nitrate-reducing bacteria was first suggested about two decades ago. It has since been found that most strains are mixotrophic and need an additional organic co-substrate for complete and prolonged Fe(II) oxidation. Research during the last few years has tried to determine to what extent the observed Fe(II) oxidation is driven enzymatically, or abiotically by nitrite produced during heterotrophic denitrification. A recent study reported that nitrite was not able to oxidize Fe(II)-EDTA abiotically, but the addition of the mixotrophic nitrate-reducing Fe(II)-oxidizer, Acidovorax sp. strain 2AN, led to Fe(II) oxidation (Chakraborty & Picardal, 2013). This, along with other results of that study, was used to argue that Fe(II) oxidation in strain 2AN was enzymatically catalyzed. However, the absence of abiotic Fe(II)-EDTA oxidation by nitrite reported in that study contrasts with previously published data. We have repeated the abiotic and biotic experiments and observed rapid abiotic oxidation of Fe(II)-EDTA by nitrite, resulting in the formation of Fe(III)-EDTA and the green Fe(II)-EDTA-NO complex. Additionally, we found that cultivating the Acidovorax strains BoFeN1 and 2AN with 10 mM nitrate, 5 mm acetate, and approximately 10 mM Fe(II)-EDTA resulted only in incomplete Fe(II)-EDTA oxidation of 47-71%. Cultures of strain BoFeN1 turned green (due to the presence of Fe(II)-EDTA-NO) and the green color persisted over the course of the experiments, whereas strain 2AN was able to further oxidize the Fe(II)-EDTA-NO complex. Our work shows that the two used Acidovorax strains behave very differently in their ability to deal with toxic effects of Fe-EDTA species and the further reduction of the Fe(II)-EDTA-NO nitrosyl complex. Although the enzymatic oxidation of Fe(II) cannot be ruled out, this study underlines the importance of nitrite in nitrate-reducing Fe(II)- and Fe(II)-EDTA-oxidizing cultures and demonstrates that Fe(II)-EDTA cannot be used to demonstrate unequivocally the enzymatic oxidation of Fe(II) by mixotrophic Fe(II)-oxidizers.
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Affiliation(s)
- N Klueglein
- Geomicrobiology, Center for Applied Geosciences, University of Tuebingen, Tuebingen, Germany
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23
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Chen M, Zhou J, Zhang Y, Wang X, Shi Z, Wang X. Fe(III)EDTA and Fe(II)EDTA-NO reduction by a sulfate reducing bacterium in NO and SO₂ scrubbing liquor. World J Microbiol Biotechnol 2015; 31:527-34. [PMID: 25649204 DOI: 10.1007/s11274-015-1813-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 01/30/2015] [Indexed: 10/24/2022]
Abstract
A viable process concept, based on NO and SO2 absorption into an alkaline Fe(II)EDTA (EDTA: ethylenediaminetetraacetic acid) solution in a scrubber combined with biological reduction of the absorbed SO2 utilizing sulfate reducing bacteria (SRB) and regeneration of the scrubbing liquor in a single bioreactor, was developed. The SRB, Desulfovibrio sp. CMX, was used and its sulfate reduction performances in FeEDTA solutions and Fe(II)EDTA-NO had been investigated. In this study, the detailed regeneration process of Fe(II)EDTA solution, which contained Fe(III)EDTA and Fe(II)EDTA-NO reduction processes in presence of D. sp. CMX and sulfate, was evaluated. Fe(III)EDTA and Fe(II)EDTA-NO reduction processes were primarily biological, even if Fe(III)EDTA and Fe(II)EDTA-NO could also be chemically convert to Fe(II)EDTA by biogenic sulfide. Regardless presence or absence of sulfate, more than 87 % Fe(III)EDTA and 98 % Fe(II)EDTA-NO were reduced in 46 h, respectively. Sulfate and Fe(III)EDTA had no affection on Fe(II)EDTA-NO reduction. Sulfate enhanced final Fe(III)EDTA reduction. Effect of Fe(III)EDTA on Fe(II)EDTA-NO reduction rate was more obvious than effect of sulfate on Fe(II)EDTA-NO reduction rate before 8 h. To overcome toxicity of Fe(II)EDTA-NO on SRB, Fe(II)EDTA-NO was reduced first and the reduction of Fe(III)EDTA and sulfate occurred after 2 h. First-order Fe(II)EDTA-NO reduction rate and zero-order Fe(III)EDTA reduction rate were detected respectively before 8 h.
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Affiliation(s)
- Mingxiang Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, 116024, People's Republic of China
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24
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Assessing Microbial Contributions to N2O Impacts Following Biochar Additions. AGRONOMY-BASEL 2014. [DOI: 10.3390/agronomy4040478] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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25
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Research of Iron Reduction and the Iron Reductase Localization of Anammox Bacteria. Curr Microbiol 2014; 69:880-7. [DOI: 10.1007/s00284-014-0668-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 06/15/2014] [Indexed: 10/24/2022]
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26
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Liu T, Li X, Zhang W, Hu M, Li F. Fe(III) oxides accelerate microbial nitrate reduction and electricity generation by Klebsiella pneumoniae L17. J Colloid Interface Sci 2014; 423:25-32. [DOI: 10.1016/j.jcis.2014.02.026] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 02/19/2014] [Accepted: 02/21/2014] [Indexed: 10/25/2022]
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27
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Etique M, Jorand FPA, Zegeye A, Grégoire B, Despas C, Ruby C. Abiotic process for Fe(II) oxidation and green rust mineralization driven by a heterotrophic nitrate reducing bacteria (Klebsiella mobilis). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:3742-3751. [PMID: 24605878 DOI: 10.1021/es403358v] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Green rusts (GRs) are mixed Fe(II)-Fe(III) hydroxides with a high reactivity toward organic and inorganic pollutants. GRs can be produced from ferric reducing or ferrous oxidizing bacterial activities. In this study, we investigated the capability of Klebsiella mobilis to produce iron minerals in the presence of nitrate and ferrous iron. This bacterium is well-known to reduce nitrate using an organic carbon source as electron donor but is unable to enzymatically oxidize Fe(II) species. During incubation, GR formation occurred as a secondary iron mineral precipitating on cell surfaces, resulting from Fe(II) oxidation by nitrite produced via bacterial respiration of nitrate. For the first time, we demonstrate GR formation by indirect microbial oxidation of Fe(II) (i.e., a combination of biotic/abiotic processes). These results therefore suggest that nitrate-reducing bacteria can potentially contribute to the formation of GR in natural environments. In addition, the chemical reduction of nitrite to ammonium by GR is observed, which gradually turns the GR into the end-product goethite. The nitrogen mass-balance clearly demonstrates that the total amount of ammonium produced corresponds to the quantity of bioreduced nitrate. These findings demonstrate how the activity of nitrate-reducing bacteria in ferrous environments may provide a direct link between the biogeochemical cycles of nitrogen and iron.
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Affiliation(s)
- Marjorie Etique
- Université de Lorraine , Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, Institut Jean Barriol, Villers-lès-Nancy, F-54601, France
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28
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Competitive reduction of nitrate and iron oxides by Shewanella putrefaciens 200 under anoxic conditions. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.01.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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29
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Yu HY, Wang YK, Chen PC, Li FB, Chen MJ, Hu M, Ouyang X. Effect of nitrate addition on reductive transformation of pentachlorophenol in paddy soil in relation to iron(III) reduction. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2014; 132:42-48. [PMID: 24286925 DOI: 10.1016/j.jenvman.2013.10.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 10/16/2013] [Accepted: 10/28/2013] [Indexed: 06/02/2023]
Abstract
Reductive dechlorination is a crucial pathway for anaerobic biodegradation of highly chlorinated organic contaminants. Under an anoxic environment, reductive dechlorination of organic contaminants can be affected by many redox processes such as nitrate reduction and iron reduction. In the present study, batch incubation experiments were conducted to investigate the effect of nitrate addition on reductive dechlorination of PCP in paddy soil with consideration of iron transformation. Study results demonstrate that low concentrations (0, 0.5 and 1 mM) of nitrate addition can enhance the reductive dechlorination of PCP and Fe(III) reduction, while high concentrations (5, 10, 20 and 30 mM) of nitrate addition caused the contrary. Significant positive correlations between PCP degradation rates and the formation rates of dissolved Fe(II) (pearson correlation coefficients r = 0.965) and HCl-extractable Fe(II) (r = 0.921) suggested that Fe(III) reduction may enhance PCP dechlorination. Furthermore, consistent variation trends of PCP degradation and the abundances of the genus Comamonas, capable of Fe(III) reduction coupled to reductive dechlorination, and of the genus Dehalobacter indicated the occurrence of microbial community variation induced by nitrate addition as a response to PCP dechlorination.
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Affiliation(s)
- Huan-Yun Yu
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, China
| | - Yong-kui Wang
- Environmental Science and Engineering College, Hubei Polytechic University, Huangshi, Hubei 435003, China
| | - Peng-cheng Chen
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, China
| | - Fang-bai Li
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, China.
| | - Man-jia Chen
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, China
| | - Min Hu
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, China
| | - Xiaoguang Ouyang
- Beijing Zhongqi Anxin Environmental Science & Technology Co., Ltd., China
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30
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Potential role of nitrite for abiotic Fe(II) oxidation and cell encrustation during nitrate reduction by denitrifying bacteria. Appl Environ Microbiol 2013; 80:1051-61. [PMID: 24271182 DOI: 10.1128/aem.03277-13] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microorganisms have been observed to oxidize Fe(II) at neutral pH under anoxic and microoxic conditions. While most of the mixotrophic nitrate-reducing Fe(II)-oxidizing bacteria become encrusted with Fe(III)-rich minerals, photoautotrophic and microaerophilic Fe(II) oxidizers avoid cell encrustation. The Fe(II) oxidation mechanisms and the reasons for encrustation remain largely unresolved. Here we used cultivation-based methods and electron microscopy to compare two previously described nitrate-reducing Fe(II) oxidizers ( Acidovorax sp. strain BoFeN1 and Pseudogulbenkiania sp. strain 2002) and two heterotrophic nitrate reducers (Paracoccus denitrificans ATCC 19367 and P. denitrificans Pd 1222). All four strains oxidized ∼8 mM Fe(II) within 5 days in the presence of 5 mM acetate and accumulated nitrite (maximum concentrations of 0.8 to 1.0 mM) in the culture media. Iron(III) minerals, mainly goethite, formed and precipitated extracellularly in close proximity to the cell surface. Interestingly, mineral formation was also observed within the periplasm and cytoplasm; intracellular mineralization is expected to be physiologically disadvantageous, yet acetate consumption continued to be observed even at an advanced stage of Fe(II) oxidation. Extracellular polymeric substances (EPS) were detected by lectin staining with fluorescence microscopy, particularly in the presence of Fe(II), suggesting that EPS production is a response to Fe(II) toxicity or a strategy to decrease encrustation. Based on the data presented here, we propose a nitrite-driven, indirect mechanism of cell encrustation whereby nitrite forms during heterotrophic denitrification and abiotically oxidizes Fe(II). This work adds to the known assemblage of Fe(II)-oxidizing bacteria in nature and complicates our ability to delineate microbial Fe(II) oxidation in ancient microbes preserved as fossils in the geological record.
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31
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Fe(II) oxidation is an innate capability of nitrate-reducing bacteria that involves abiotic and biotic reactions. J Bacteriol 2013; 195:3260-8. [PMID: 23687275 DOI: 10.1128/jb.00058-13] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Phylogenetically diverse species of bacteria can catalyze the oxidation of ferrous iron [Fe(II)] coupled to nitrate (NO(3)(-)) reduction, often referred to as nitrate-dependent iron oxidation (NDFO). Very little is known about the biochemistry of NDFO, and though growth benefits have been observed, mineral encrustations and nitrite accumulation likely limit growth. Acidovorax ebreus, like other species in the Acidovorax genus, is proficient at catalyzing NDFO. Our results suggest that the induction of specific Fe(II) oxidoreductase proteins is not required for NDFO. No upregulated periplasmic or outer membrane redox-active proteins, like those involved in Fe(II) oxidation by acidophilic iron oxidizers or anaerobic photoferrotrophs, were observed in proteomic experiments. We demonstrate that while "abiotic" extracellular reactions between Fe(II) and biogenic NO(2)(-)/NO can be involved in NDFO, intracellular reactions between Fe(II) and periplasmic components are essential to initiate extensive NDFO. We present evidence that an organic cosubstrate inhibits NDFO, likely by keeping periplasmic enzymes in their reduced state, stimulating metal efflux pumping, or both, and that growth during NDFO relies on the capacity of a nitrate-reducing bacterium to overcome the toxicity of Fe(II) and reactive nitrogen species. On the basis of our data and evidence in the literature, we postulate that all respiratory nitrate-reducing bacteria are innately capable of catalyzing NDFO. Our findings have implications for a mechanistic understanding of NDFO, the biogeochemical controls on anaerobic Fe(II) oxidation, and the production of NO(2)(-), NO, and N(2)O in the environment.
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32
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Kopf S, Henny C, Newman DK. Ligand-enhanced abiotic iron oxidation and the effects of chemical versus biological iron cycling in anoxic environments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:2602-11. [PMID: 23402562 PMCID: PMC3604861 DOI: 10.1021/es3049459] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
This study introduces a newly isolated, genetically tractable bacterium ( Pseudogulbenkiania sp. strain MAI-1) and explores the extent to which its nitrate-dependent iron-oxidation activity is directly biologically catalyzed. Specifically, we focused on the role of iron chelating ligands in promoting chemical oxidation of Fe(II) by nitrite under anoxic conditions. Strong organic ligands such as nitrilotriacetate and citrate can substantially enhance chemical oxidation of Fe(II) by nitrite at circumneutral pH. We show that strain MAI-1 exhibits unambiguous biological Fe(II) oxidation despite a significant contribution (∼30-35%) from ligand-enhanced chemical oxidation. Our work with the model denitrifying strain Paracoccus denitrificans further shows that ligand-enhanced chemical oxidation of Fe(II) by microbially produced nitrite can be an important general side effect of biological denitrification. Our assessment of reaction rates derived from literature reports of anaerobic Fe(II) oxidation, both chemical and biological, highlights the potential competition and likely co-occurrence of chemical Fe(II) oxidation (mediated by microbial production of nitrite) and truly biological Fe(II) oxidation.
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Affiliation(s)
- Sebastian
H. Kopf
- Division
of Geologial and Planetary Sciences and Division of Biology, California Institute of Technology,
Pasadena, California, United States
| | - Cynthia Henny
- Research Center for
Limnology, LIPI, Cibinong, Indonesia
| | - Dianne K. Newman
- Division
of Geologial and Planetary Sciences and Division of Biology, California Institute of Technology,
Pasadena, California, United States
- Howard Hughes Medical
Institute, Pasadena, California, United States
- Phone: 626-395-3543. Fax: 626-395-4135. E-mail:
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33
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Chandrashekhar B, Pai P, Morone A, Sahu N, Pandey RA. Reduction of NOx in Fe-EDTA and Fe-NTA solutions by an enriched bacterial population. BIORESOURCE TECHNOLOGY 2013; 130:644-651. [PMID: 23334022 DOI: 10.1016/j.biortech.2012.12.051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/07/2012] [Accepted: 12/08/2012] [Indexed: 06/01/2023]
Abstract
An enriched biomass was developed from municipal sewage sludge consisting of three dominant bacteria, representing the genera of Enterobacter, Citrobacter and Streptomyces. The biomass was used in a series of batch experiments in order to determine kinetic constants associated with biomass growth and NOx reduction in aqueous Ferrous EDTA/NTA solutions and Ferric EDTA/NTA solutions using ethanol as organic electron donor. The maximum specific reduction rates of NOx in Ferrous EDTA and Ferrous NTA solutions were 0.037 and 0.047mMolesL(-1)d(-1)mg(-1) biomass, respectively while in Ferric EDTA and Ferric NTA solutions were 0.022 and 0.024mMolesL(-1)d(-1)mg(-1) biomass, respectively. In case of Ferric EDTA/NTA solution, the kinetic constants associated with reduction of Ferric EDTA/NTA to Ferrous EDTA/NTA were also evaluated simultaneously. The maximum specific reduction rates of Ferric EDTA and Ferric NTA were 0.0021 and 0.0026mMolesL(-1)d(-1)mg(-1) biomass. The significance of these observations are presented and discussed in this paper.
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Affiliation(s)
- B Chandrashekhar
- Environmental Biotechnology Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440020, India
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34
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Khilyas IV, Ziganshin AM, Pannier AJ, Gerlach R. Effect of ferrihydrite on 2,4,6-trinitrotoluene biotransformation by an aerobic yeast. Biodegradation 2012; 24:631-44. [DOI: 10.1007/s10532-012-9611-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 11/27/2012] [Indexed: 10/27/2022]
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35
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Genomic plasticity enables a secondary electron transport pathway in Shewanella oneidensis. Appl Environ Microbiol 2012; 79:1150-9. [PMID: 23220953 DOI: 10.1128/aem.03556-12] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial dissimilatory iron reduction is an important biogeochemical process. It is physiologically challenging because iron occurs in soils and sediments in the form of insoluble minerals such as hematite or ferrihydrite. Shewanella oneidensis MR-1 evolved an extended respiratory chain to the cell surface to reduce iron minerals. Interestingly, the organism evolved a similar strategy for reduction of dimethyl sulfoxide (DMSO), which is reduced at the cell surface as well. It has already been established that electron transfer through the outer membrane is accomplished via a complex in which β-barrel proteins enable interprotein electron transfer between periplasmic oxidoreductases and cell surface-localized terminal reductases. MtrB is the β-barrel protein that is necessary for dissimilatory iron reduction. It forms a complex together with the periplasmic decaheme c-type cytochrome MtrA and the outer membrane decaheme c-type cytochrome MtrC. Consequently, mtrB deletion mutants are unable to reduce ferric iron. The data presented here show that this inability can be overcome by a mobile genomic element with the ability to activate the expression of downstream genes and which is inserted within the SO4362 gene of the SO4362-to-SO4357 gene cluster. This cluster carries genes similar to mtrA and mtrB and encoding a putative cell surface DMSO reductase. Expression of SO4359 and SO4360 alone was sufficient to complement not only an mtrB mutant under ferric citrate-reducing conditions but also a mutant that furthermore lacks any outer membrane cytochromes. Hence, the putative complex formed by the SO4359 and SO4360 gene products is capable not only of membrane-spanning electron transfer but also of reducing extracellular electron acceptors.
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36
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Chakraborty A, Picardal F. Neutrophilic, nitrate-dependent, Fe(II) oxidation by a Dechloromonas species. World J Microbiol Biotechnol 2012. [DOI: 10.1007/s11274-012-1217-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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37
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Unexpected nondenitrifier nitrous oxide reductase gene diversity and abundance in soils. Proc Natl Acad Sci U S A 2012; 109:19709-14. [PMID: 23150571 DOI: 10.1073/pnas.1211238109] [Citation(s) in RCA: 320] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Agricultural and industrial practices more than doubled the intrinsic rate of terrestrial N fixation over the past century with drastic consequences, including increased atmospheric nitrous oxide (N(2)O) concentrations. N(2)O is a potent greenhouse gas and contributor to ozone layer destruction, and its release from fixed N is almost entirely controlled by microbial activities. Mitigation of N(2)O emissions to the atmosphere has been attributed exclusively to denitrifiers possessing NosZ, the enzyme system catalyzing N(2)O to N(2) reduction. We demonstrate that diverse microbial taxa possess divergent nos clusters with genes that are related yet evolutionarily distinct from the typical nos genes of denitirifers. nos clusters with atypical nosZ occur in Bacteria and Archaea that denitrify (44% of genomes), do not possess other denitrification genes (56%), or perform dissimilatory nitrate reduction to ammonium (DNRA; (31%). Experiments with the DNRA soil bacterium Anaeromyxobacter dehalogenans demonstrated that the atypical NosZ is an effective N(2)O reductase, and PCR-based surveys suggested that atypical nosZ are abundant in terrestrial environments. Bioinformatic analyses revealed that atypical nos clusters possess distinctive regulatory and functional components (e.g., Sec vs. Tat secretion pathway in typical nos), and that previous nosZ-targeted PCR primers do not capture the atypical nosZ diversity. Collectively, our results suggest that nondenitrifying populations with a broad range of metabolisms and habitats are potentially significant contributors to N(2)O consumption. Apparently, a large, previously unrecognized group of environmental nosZ has not been accounted for, and characterizing their contributions to N(2)O consumption will advance understanding of the ecological controls on N(2)O emissions and lead to refined greenhouse gas flux models.
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38
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Induction of nitrate-dependent Fe(II) oxidation by Fe(II) in Dechloromonas sp. strain UWNR4 and Acidovorax sp. strain 2AN. Appl Environ Microbiol 2012; 79:748-52. [PMID: 23144134 DOI: 10.1128/aem.02709-12] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We evaluated the inducibility of nitrate-dependent Fe(II)-EDTA oxidation (NDFO) in non-growth, chloramphenicol-amended, resting-cell suspensions of Dechloromonas sp. strain UWNR4 and Acidovorax sp. strain 2AN. Cells previously incubated with Fe(II)-EDTA oxidized ca. 6-fold more Fe(II)-EDTA than cells previously incubated with Fe(III)-EDTA. This is the first report of induction of NDFO by Fe(II).
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39
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Xiao X, Xu CC, Wu YM, Cai PJ, Li WW, Du DL, Yu HQ. Biodecolorization of Naphthol Green B dye by Shewanella oneidensis MR-1 under anaerobic conditions. BIORESOURCE TECHNOLOGY 2012; 110:86-90. [PMID: 22349191 DOI: 10.1016/j.biortech.2012.01.099] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 01/14/2012] [Accepted: 01/19/2012] [Indexed: 05/31/2023]
Abstract
The anaerobic decolorization of metal-complex dye Naphthol Green B (NGB) by a metal-reducing bacterium, Shewanella oneidensis MR-1, was investigated. S. oneidensis MR-1 showed a high capacity for decolorizing NGB even at a concentration of up to 1000mg/L under anaerobic conditions. Maximum decolorization efficiency was appeared at pH 8.0 and 40°C. Addition of iron oxide caused no inhibition to the NGB decolorization, while the presence of ferric citrate, nitrite, or nitrate almost completely terminated the decolorization. Biosynthesis of nanomaterials was observed coupled with the degradation of NGB when thiosulfate was added. The Mtr respiratory pathway was found to be responsible for the decolorization of NGB by S. oneidensis, in which extracellular electron shuttle also plays a positive role in promoting the decolorization.
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Affiliation(s)
- Xiang Xiao
- School of Environment, Jiangsu University, Zhenjiang 212013, China
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40
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Picardal F. Abiotic and Microbial Interactions during Anaerobic Transformations of Fe(II) and [Formula: see text]. Front Microbiol 2012; 3:112. [PMID: 22479259 PMCID: PMC3314871 DOI: 10.3389/fmicb.2012.00112] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 03/09/2012] [Indexed: 11/13/2022] Open
Abstract
Microbial Fe(II) oxidation using [Formula: see text] as the terminal electron acceptor [nitrate-dependent Fe(II) oxidation, NDFO] has been studied for over 15 years. Although there are reports of autotrophic isolates and stable enrichments, many of the bacteria capable of NDFO are known organotrophic [Formula: see text]-reducers that require the presence of an organic, primary substrate, e.g., acetate, for significant amounts of Fe(II) oxidation. Although the thermodynamics of Fe(II) oxidation are favorable when coupled to either [Formula: see text] or [Formula: see text] reduction, the kinetics of abiotic Fe(II) oxidation by [Formula: see text] are relatively slow except under special conditions. NDFO is typically studied in batch cultures containing millimolar concentrations of Fe(II), [Formula: see text], and the primary substrate. In such systems, [Formula: see text] is often observed to accumulate in culture media during Fe(II) oxidation. Compared to [Formula: see text] abiotic reactions of biogenic [Formula: see text] and Fe(II) are relatively rapid. The kinetics and reaction pathways of Fe(II) oxidation by [Formula: see text] are strongly affected by medium composition and pH, reactant concentration, and the presence of Fe(II)-sorptive surfaces, e.g., Fe(III) oxyhydroxides and cellular surfaces. In batch cultures, the combination of abiotic and microbial Fe(II) oxidation can alter product distribution and, more importantly, results in the formation of intracellular precipitates and extracellular Fe(III) oxyhydroxide encrustations that apparently limit further cell growth and Fe(II) oxidation. Unless steps are taken to minimize or account for potential abiotic reactions, results of microbial NDFO studies can be obfuscated by artifacts of the chosen experimental conditions, the use of inappropriate analytical methods, and the resulting uncertainties about the relative importance of abiotic and microbial reactions. In this manuscript, abiotic reactions of [Formula: see text] and [Formula: see text] with aqueous Fe(2+), chelated Fe(II), and solid-phase Fe(II) are reviewed along with factors that can influence overall NDFO reaction rates in microbial systems. In addition, the use of low substrate concentrations, continuous-flow systems, and experimental protocols that minimize experimental artifacts and reduce the potential for under- or overestimation of microbial NDFO rates are discussed.
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Affiliation(s)
- Flynn Picardal
- School of Public and Environmental Affairs, Indiana UniversityBloomington, IN, USA
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41
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Carlson HK, Clark IC, Melnyk RA, Coates JD. Toward a mechanistic understanding of anaerobic nitrate-dependent iron oxidation: balancing electron uptake and detoxification. Front Microbiol 2012; 3:57. [PMID: 22363331 PMCID: PMC3282478 DOI: 10.3389/fmicb.2012.00057] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 02/02/2012] [Indexed: 11/25/2022] Open
Abstract
The anaerobic oxidation of Fe(II) by subsurface microorganisms is an important part of biogeochemical cycling in the environment, but the biochemical mechanisms used to couple iron oxidation to nitrate respiration are not well understood. Based on our own work and the evidence available in the literature, we propose a mechanistic model for anaerobic nitrate-dependent iron oxidation. We suggest that anaerobic iron-oxidizing microorganisms likely exist along a continuum including: (1) bacteria that inadvertently oxidize Fe(II) by abiotic or biotic reactions with enzymes or chemical intermediates in their metabolic pathways (e.g., denitrification) and suffer from toxicity or energetic penalty, (2) Fe(II) tolerant bacteria that gain little or no growth benefit from iron oxidation but can manage the toxic reactions, and (3) bacteria that efficiently accept electrons from Fe(II) to gain a growth advantage while preventing or mitigating the toxic reactions. Predictions of the proposed model are highlighted and experimental approaches are discussed.
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Affiliation(s)
- Hans K Carlson
- Department of Plant and Microbial Biology, University of California Berkeley Berkeley, CA, USA
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42
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Haaijer SCM, Crienen G, Jetten MSM, Op den Camp HJM. Anoxic iron cycling bacteria from an iron sulfide- and nitrate-rich freshwater environment. Front Microbiol 2012; 3:26. [PMID: 22347219 PMCID: PMC3271277 DOI: 10.3389/fmicb.2012.00026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 01/16/2012] [Indexed: 11/30/2022] Open
Abstract
In this study, both culture-dependent and culture-independent methods were used to determine whether the iron sulfide mineral- and nitrate-rich freshwater nature reserve Het Zwart Water accommodates anoxic microbial iron cycling. Molecular analyses (16S rRNA gene clone library and fluorescence in situ hybridization, FISH) showed that sulfur-oxidizing denitrifiers dominated the microbial population. In addition, bacteria resembling the iron-oxidizing, nitrate-reducing Acidovorax strain BrG1 accounted for a major part of the microbial community in the groundwater of this ecosystem. Despite the apparent abundance of strain BrG1-like bacteria, iron-oxidizing nitrate reducers could not be isolated, likely due to the strictly autotrophic cultivation conditions adopted in our study. In contrast an iron-reducing Geobacter sp. was isolated from this environment while FISH and 16S rRNA gene clone library analyses did not reveal any Geobacter sp.-related sequences in the groundwater. Our findings indicate that iron-oxidizing nitrate reducers may be of importance to the redox cycling of iron in the groundwater of our study site and illustrate the necessity of employing both culture-dependent and independent methods in studies on microbial processes.
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Affiliation(s)
- Suzanne C M Haaijer
- Department of Microbiology, Institute for Water and Wetland Research, Radboud University Nijmegen Nijmegen, Netherlands
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43
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Aerobic bioreduction of nickel(II) to elemental nickel with concomitant biomineralization. Appl Microbiol Biotechnol 2012; 96:273-81. [DOI: 10.1007/s00253-011-3827-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 11/20/2011] [Accepted: 12/07/2011] [Indexed: 10/14/2022]
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44
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Enhanced growth of Acidovorax sp. strain 2AN during nitrate-dependent Fe(II) oxidation in batch and continuous-flow systems. Appl Environ Microbiol 2011; 77:8548-56. [PMID: 22003007 DOI: 10.1128/aem.06214-11] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial nitrate-dependent, Fe(II) oxidation (NDFO) is a ubiquitous biogeochemical process in anoxic sediments. Since most microorganisms that can oxidize Fe(II) with nitrate require an additional organic substrate for growth or sustained Fe(II) oxidation, the energetic benefits of NDFO are unclear. The process may also be self-limiting in batch cultures due to formation of Fe-oxide cell encrustations. We hypothesized that NDFO provides energetic benefits via a mixotrophic physiology in environments where cells encounter very low substrate concentrations, thereby minimizing cell encrustations. Acidovorax sp. strain 2AN was incubated in anoxic batch reactors in a defined medium containing 5 to 6 mM NO₃⁻, 8 to 9 mM Fe²⁺, and 1.5 mM acetate. Almost 90% of the Fe(II) was oxidized within 7 days with concomitant reduction of nitrate and complete consumption of acetate. Batch-grown cells became heavily encrusted with Fe(III) oxyhydroxides, lost motility, and formed aggregates. Encrusted cells could neither oxidize more Fe(II) nor utilize further acetate additions. In similar experiments with chelated iron (Fe(II)-EDTA), encrusted cells were not produced, and further additions of acetate and Fe(II)-EDTA could be oxidized. Experiments using a novel, continuous-flow culture system with low concentrations of substrate, e.g., 100 μM NO₃⁻, 20 μM acetate, and 50 to 250 μM Fe²⁺, showed that the growth yield of Acidovorax sp. strain 2AN was always greater in the presence of Fe(II) than in its absence, and electron microscopy showed that encrustation was minimized. Our results provide evidence that, under environmentally relevant concentrations of substrates, NDFO can enhance growth without the formation of growth-limiting cell encrustations.
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Chen X, Sun G, Xu M. Role of iron in azoreduction by resting cells of Shewanella decolorationis S12. J Appl Microbiol 2010; 110:580-6. [DOI: 10.1111/j.1365-2672.2010.04913.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Denitration of 2,4,6-trinitrotoluene by Pseudomonas aeruginosa ESA-5 in the presence of ferrihydrite. Appl Microbiol Biotechnol 2008; 79:489-97. [DOI: 10.1007/s00253-008-1434-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2008] [Accepted: 02/24/2008] [Indexed: 10/22/2022]
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