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Hunt KA, Carr AV, Otwell AE, Valenzuela JJ, Walker KS, Dixon ER, Lui LM, Nielsen TN, Bowman S, von Netzer F, Moon JW, Schadt CW, Rodriguez M, Lowe K, Joyner D, Davis KJ, Wu X, Chakraborty R, Fields MW, Zhou J, Hazen TC, Arkin AP, Wankel SD, Baliga NS, Stahl DA. Contribution of Microorganisms with the Clade II Nitrous Oxide Reductase to Suppression of Surface Emissions of Nitrous Oxide. Environ Sci Technol 2024; 58:7056-7065. [PMID: 38608141 DOI: 10.1021/acs.est.3c07972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
The sources and sinks of nitrous oxide, as control emissions to the atmosphere, are generally poorly constrained for most environmental systems. Initial depth-resolved analysis of nitrous oxide flux from observation wells and the proximal surface within a nitrate contaminated aquifer system revealed high subsurface production but little escape from the surface. To better understand the environmental controls of production and emission at this site, we used a combination of isotopic, geochemical, and molecular analyses to show that chemodenitrification and bacterial denitrification are major sources of nitrous oxide in this subsurface, where low DO, low pH, and high nitrate are correlated with significant nitrous oxide production. Depth-resolved metagenomes showed that consumption of nitrous oxide near the surface was correlated with an enrichment of Clade II nitrous oxide reducers, consistent with a growing appreciation of their importance in controlling release of nitrous oxide to the atmosphere. Our work also provides evidence for the reduction of nitrous oxide at a pH of 4, well below the generally accepted limit of pH 5.
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Affiliation(s)
- Kristopher A Hunt
- Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Alex V Carr
- Department of Molecular Engineering Sciences, University of Washington, Seattle, Washington 98105, United States
- Institute for Systems Biology, Seattle, Washington 98109, United States
| | - Anne E Otwell
- Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington 98195, United States
| | | | - Kathleen S Walker
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Emma R Dixon
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Lauren M Lui
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Torben N Nielsen
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Samuel Bowman
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02540, United States
| | - Frederick von Netzer
- Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Ji-Won Moon
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Christopher W Schadt
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Miguel Rodriguez
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Kenneth Lowe
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Dominique Joyner
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Katherine J Davis
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana 59717, United States
| | - Xiaoqin Wu
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Romy Chakraborty
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Matthew W Fields
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana 59717, United States
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana 59717, United States
| | - Jizhong Zhou
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Institute for Environmental Genomics and Department of Botany and Microbiology, University of Oklahoma, Norman, Oklahoma 73019, United States
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Terry C Hazen
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Adam P Arkin
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Bioengineering, University of California Berkeley, Berkeley, California 94720, United States
| | - Scott D Wankel
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02540, United States
| | - Nitin S Baliga
- Department of Molecular Engineering Sciences, University of Washington, Seattle, Washington 98105, United States
- Institute for Systems Biology, Seattle, Washington 98109, United States
| | - David A Stahl
- Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington 98195, United States
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Song L, Wang A, Li Z, Kang R, Walters WW, Pan Y, Quan Z, Huang S, Fang Y. Large Seasonal Variation in Nitrogen Isotopic Abundances of Ammonia Volatilized from a Cropland Ecosystem and Implications for Regional NH 3 Source Partitioning. Environ Sci Technol 2024; 58:1177-1186. [PMID: 38170897 DOI: 10.1021/acs.est.3c08800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Ammonia (NH3) volatilization from agricultural lands is a main source of atmospheric reduced nitrogen species (NHx). Accurately quantifying its contribution to regional atmospheric NHx deposition is critical for controlling regional air nitrogen pollution. The stable nitrogen isotope composition (expressed by δ15N) is a promising indicator to trace atmospheric NHx sources, presupposing a reliable nitrogen isotopic signature of NH3 emission sources. To obtain more specific seasonal δ15N values of soil NH3 volatilization for reliable regional seasonal NH3 source partitioning, we utilized an active dynamic sampling technique to measure the δ15N-NH3 values volatilized from maize cropping land in northeast China. These values varied from -38.0 to -0.2‰, with a significantly lower rate-weighted value observed in the early period (May-June, -30.5 ± 6.7‰) as compared with the late period (July-October, -8.5 ± 4.3‰). Seasonal δ15N-NH3 variations were related to the main NH3 production pathway, degree of soil ammonium consumption, and soil environment. Bayesian isotope mixing model analysis revealed that without considering the seasonal δ15N variation in soil-volatilized NH3 could result in an overestimate by up to absolute 38% for agricultural volatile NH3 to regional atmospheric bulk ammonium deposition during July-October, further demonstrating that it is essential to distinguish seasonal δ15N profile of agricultural volatile NH3 in regional source apportionment.
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Affiliation(s)
- Linlin Song
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China
- Key Laboratory of Stable Isotope Techniques and Applications, Shenyang, Liaoning 110016, China
| | - Ang Wang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China
- Key Laboratory of Stable Isotope Techniques and Applications, Shenyang, Liaoning 110016, China
| | - Zhengjie Li
- College of Biological Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
| | - Ronghua Kang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China
- Key Laboratory of Stable Isotope Techniques and Applications, Shenyang, Liaoning 110016, China
| | - Wendell W Walters
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Yuepeng Pan
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Zhi Quan
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China
- Key Laboratory of Stable Isotope Techniques and Applications, Shenyang, Liaoning 110016, China
| | - Shaonan Huang
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China
| | - Yunting Fang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China
- Key Laboratory of Stable Isotope Techniques and Applications, Shenyang, Liaoning 110016, China
- Qingyuan Forest CERN, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China
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Martínez-Sancho E, Cernusak LA, Fonti P, Gregori A, Ullrich B, Pannatier EG, Gessler A, Lehmann MM, Saurer M, Treydte K. Unenriched xylem water contribution during cellulose synthesis influenced by atmospheric demand governs the intra-annual tree-ring δ 18 O signature. New Phytol 2023; 240:1743-1757. [PMID: 37753542 DOI: 10.1111/nph.19278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/16/2023] [Indexed: 09/28/2023]
Abstract
The oxygen isotope composition (δ18 O) of tree-ring cellulose is used to evaluate tree physiological responses to climate, but their interpretation is still limited due to the complexity of the isotope fractionation pathways. We assessed the relative contribution of seasonal needle and xylem water δ18 O variations to the intra-annual tree-ring cellulose δ18 O signature of larch trees at two sites with contrasting soil water availability in the Swiss Alps. We combined biweekly δ18 O measurements of soil water, needle water, and twig xylem water with intra-annual δ18 O measurements of tree-ring cellulose, xylogenesis analysis, and mechanistic and structural equation modeling. Intra-annual cellulose δ18 O values resembled source water δ18 O mean levels better than needle water δ18 O. Large parts of the rings were formed under high proportional exchange with unenriched xylem water (pex ). Maximum pex values were achieved in August and imprinted on sections at 50-75% of the ring. High pex values were associated with periods of high atmospheric evaporative demand (VPD). While VPD governed needle water δ18 O variability, we estimated a limited Péclet effect at both sites. Due to a variable pex , source water has a strong influence over large parts of the intra-annual tree-ring cellulose δ18 O variations, potentially masking signals coming from needle-level processes.
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Affiliation(s)
- Elisabet Martínez-Sancho
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
- Department of Biological Evolution, Ecology and Environmental Sciences, University of Barcelona, Diagonal 643, Barcelona, 08028, Spain
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, QLD, 4878, Australia
| | - Patrick Fonti
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Alessandro Gregori
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Bastian Ullrich
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Elisabeth Graf Pannatier
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Arthur Gessler
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Marco M Lehmann
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Matthias Saurer
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Kerstin Treydte
- Research Unit Forest Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
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Siegwolf RTW, Lehmann MM, Goldsmith GR, Churakova Sidorova OV, Mirande-Ney C, Timoveeva G, Weigt RB, Saurer M. Updating the dual C and O isotope-Gas-exchange model: A concept to understand plant responses to the environment and its implications for tree rings. Plant Cell Environ 2023. [PMID: 37283560 DOI: 10.1111/pce.14630] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 05/07/2023] [Accepted: 05/15/2023] [Indexed: 06/08/2023]
Abstract
The combined study of carbon (C) and oxygen (O) isotopes in plant organic matter has emerged as a powerful tool for understanding plant functional responses to environmental change. The approach relies on established relationships between leaf gas exchange and isotopic fractionation to derive a series of model scenarios that can be used to infer changes in photosynthetic assimilation and stomatal conductance driven by changes in environmental parameters (CO2 , water availability, air humidity, temperature, nutrients). We review the mechanistic basis for a conceptual model, in light of recently published research, and discuss where isotopic observations do not match our current understanding of plant physiological response to the environment. We demonstrate that (1) the model was applied successfully in many, but not all studies; (2) although originally conceived for leaf isotopes, the model has been applied extensively to tree-ring isotopes in the context of tree physiology and dendrochronology. Where isotopic observations deviate from physiologically plausible conclusions, this mismatch between gas exchange and isotope response provides valuable insights into underlying physiological processes. Overall, we found that isotope responses can be grouped into situations of increasing resource limitation versus higher resource availability. The dual-isotope model helps to interpret plant responses to a multitude of environmental factors.
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Affiliation(s)
- Rolf T W Siegwolf
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Marco M Lehmann
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Gregory R Goldsmith
- Schmid College of Science and Technology, Chapman University, Orange, California, USA
| | | | - Cathleen Mirande-Ney
- Ecosystem Fluxes Group, Laboratory for Atmospheric Chemistry, Paul Scherrer Institute, Villigen, Switzerland
| | - Galina Timoveeva
- Ecosystem Fluxes Group, Laboratory for Atmospheric Chemistry, Paul Scherrer Institute, Villigen, Switzerland
- ETH Alumni Association, Zürich, Switzerland
| | - Rosmarie B Weigt
- Ecosystem Fluxes Group, Laboratory for Atmospheric Chemistry, Paul Scherrer Institute, Villigen, Switzerland
| | - Matthias Saurer
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
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Guliyev V, Tanunchai B, Udovenko M, Menyailo O, Glaser B, Purahong W, Buscot F, Blagodatskaya E. Degradation of Bio-Based and Biodegradable Plastic and Its Contribution to Soil Organic Carbon Stock. Polymers (Basel) 2023; 15. [PMID: 36771962 DOI: 10.3390/polym15030660] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 01/31/2023] Open
Abstract
Expanding the use of environmentally friendly materials to protect the environment is one of the key factors in maintaining a sustainable ecological balance. Poly(butylene succinate-co-adipate) (PBSA) is considered among the most promising bio-based and biodegradable plastics for the future with a high number of applications in soil and agriculture. Therefore, the decomposition process of PBSA and its consequences for the carbon stored in soil require careful monitoring. For the first time, the stable isotope technique was applied in the current study to partitioning plastic- and soil-originated C in the CO2 released during 80 days of PBSA decomposition in a Haplic Chernozem soil as dependent on nitrogen availability. The decomposition of the plastic was accompanied by the C loss from soil organic matter (SOM) through priming, which in turn was dependent on added N. Nitrogen facilitated PBSA decomposition and reduced the priming effect during the first 6 weeks of the experiment. During the 80 days of plastic decomposition, 30% and 49% of the released CO2 were PBSA-derived, while the amount of SOM-derived CO2 exceeded the corresponding controls by 100.2 and 132.3% in PBSA-amended soil without and with N fertilization, respectively. Finally, only 4.1% and 5.4% of the PBSA added into the soil was mineralized to CO2, in the treatments without and with N amendment, respectively.
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Niu C, Zhai T, Zhang Q, Wang H, Xiao L. Research Advances in the Analysis of Nitrate Pollution Sources in a Freshwater Environment Using δ 15N-NO 3- and δ 18O-NO 3. Int J Environ Res Public Health 2021; 18:ijerph182211805. [PMID: 34831560 PMCID: PMC8623930 DOI: 10.3390/ijerph182211805] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 11/16/2022]
Abstract
Nitrate is usually the main pollution factor in the river water and groundwater environment because it has the characteristics of stable properties, high solubility and easy migration. In order to ensure the safety of water supply and effectively control nitrate pollution, it is very important to accurately identify the pollution sources of nitrate in freshwater environment. At present, as the most accurate source analysis method, isotope technology is widely used to identify the pollution sources of nitrate in water environment. However, the complexity of nitrate pollution sources and nitrogen migration and transformation in the water environment, coupled with the isotopic fractionation, has changed the nitrogen and oxygen isotopic values of nitrate in the initial water body, resulting in certain limitations in the application of this technology. This review systematically summarized the typical δ15N and δ18O-NO3- ranges of NO3- sources, described the progress in the application of isotope technique to identify nitrate pollution sources in water environment, analyzed the application of isotope technique in identifying the migration and transformation of nitrogen in water environment, and introduced the method of quantitative source apportionment. Lastly, we discussed the deficiency of isotope technique in nitrate pollution source identification and described the future development direction of the pollution source apportionment of nitrate in water environment.
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Affiliation(s)
- Chao Niu
- College of Geology and Environment, Xi’an University of Science and Technology, Xi’an 710054, China; (C.N.); (L.X.)
| | - Tianlun Zhai
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China;
| | - Qianqian Zhang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China;
- Correspondence: (Q.Z.); (H.W.)
| | - Huiwei Wang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China;
- Correspondence: (Q.Z.); (H.W.)
| | - Lele Xiao
- College of Geology and Environment, Xi’an University of Science and Technology, Xi’an 710054, China; (C.N.); (L.X.)
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Park JY, Jung JH, Kwak JH, Park HG, Kang CK, Park HJ. Trophic Enrichment Factors of Carbon and Nitrogen Isotopic Ratios (Δ 13C and Δ 15N) in Four Marine Ciliates. Front Microbiol 2021; 12:721157. [PMID: 34630351 PMCID: PMC8495318 DOI: 10.3389/fmicb.2021.721157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 08/25/2021] [Indexed: 11/29/2022] Open
Abstract
Understanding the magnitude and causes of isotopic fractionation between organisms and their dietary resources is crucial for gaining knowledge on stable isotope ecology. However, little is known regarding the diet-tissue fractionation values of marine ciliates, which play a critical role in the reconstruction of microbial food webs. In the present study, we conducted experiments on two benthic (Pseudokeronopsis pararubra and Protocruzia labiata) and two pelagic (Strombidium sulcatum and Uronemella filificum) marine ciliates, where they were fed with isotopically constant foods (Chaetoceros calcitrans and Isochrysis galbana) under laboratory culture conditions to determine their carbon and nitrogen isotopic fractionation values (Δ13C and Δ15N). The stable isotope values (δ13C and δ15N) of ciliates for all experiments rapidly increased after the initial feeding, with half-lives ranging from 6.1 to 23.0h for δ13C and from 3.1 to 24.9h for δ15N. The Δ13C and Δ15N for all ciliates represented significantly positive enrichments, with overall mean fractionations of 0.6±0.2 and 1.2±0.4, respectively. Irrespective of the dietary type, both Δ13C and Δ15N were very similar for the same ciliate species. These results suggest that Δ13C and Δ15N for marine ciliates are similar to those found in common marine organisms with very little food-dependent variation. Overall, quantifying the specific isotopic fractionation of marine ciliates is expected to provide fundamental information on the trophic transfer of carbon, nitrogen, and energy flow through the microbial pathway in marine ecosystems.
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Affiliation(s)
- Jun Young Park
- Department of Marine Bioscience, Gangneung-Wonju National University, Gangneung, South Korea
| | - Jae-Ho Jung
- Department of Biology, Gangneung-Wonju National University, Gangneung, South Korea
| | - Jung Hyun Kwak
- Jeju Fisheries Research Institute, National Institute of Fisheries Science, Jeju, South Korea
| | - Heum Gi Park
- Department of Marine Bioscience, Gangneung-Wonju National University, Gangneung, South Korea
| | - Chang-Keun Kang
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Hyun Je Park
- Department of Marine Bioscience, Gangneung-Wonju National University, Gangneung, South Korea
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Hilman B, Muhr J, Helm J, Kuhlmann I, Schulze ED, Trumbore S. The size and the age of the metabolically active carbon in tree roots. Plant Cell Environ 2021; 44:2522-2535. [PMID: 34096615 DOI: 10.1111/pce.14124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/31/2021] [Accepted: 06/01/2021] [Indexed: 06/12/2023]
Abstract
Little is known about the sources and age of C respired by tree roots. Previous research in stems identified two functional pools of non-structural carbohydrates (NSC): an "active" pool supplied directly from canopy photo-assimilates supporting metabolism and a "stored" pool used when fresh C supplies are limited. We compared the C isotope composition of water-soluble NSC and respired CO2 for aspen roots (Populus tremula hybrids) cut off from fresh C supply after stem-girdling or prolonged incubation of excised roots. We used bomb radiocarbon to estimate the time elapsed since C fixation for respired CO2 , water-soluble NSC and structural α-cellulose. While freshly excised roots (mostly <2.9 mm in diameter) respired CO2 fixed <1 year previously, the age increased to 1.6-2.9 year within a week after root excision. Freshly excised roots from trees girdled ~3 months ago had respiration rates and NSC stocks similar to un-girdled trees but respired older C (~1.2 year). We estimate that over 3 months NSC in girdled roots must be replaced 5-7 times by reserves remobilized from root-external sources. Using a mixing model and observed correlations between Δ14 C of water-soluble C and α-cellulose, we estimate ~30% of C is "active" (~5 mg C g-1 ).
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Affiliation(s)
- Boaz Hilman
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
| | - Jan Muhr
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
- Department of Bioclimatology, Georg-August University Göttingen, Göttingen, Germany
| | - Juliane Helm
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
| | - Iris Kuhlmann
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
| | - Ernst-Detlef Schulze
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
| | - Susan Trumbore
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
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Kimura H, Fuseya G, Takeya S, Hachikubo A. Carbon Isotope Fractionation during the Formation of CO 2 Hydrate and Equilibrium Pressures of 12CO 2 and 13CO 2 Hydrates. Molecules 2021; 26:4215. [PMID: 34299489 DOI: 10.3390/molecules26144215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/04/2021] [Accepted: 07/07/2021] [Indexed: 12/02/2022] Open
Abstract
Knowledge of carbon isotope fractionation is needed in order to discuss the formation and dissociation of naturally occurring CO2 hydrates. We investigated carbon isotope fractionation during CO2 hydrate formation and measured the three-phase equilibria of 12CO2–H2O and 13CO2–H2O systems. From a crystal structure viewpoint, the difference in the Raman spectra of hydrate-bound 12CO2 and 13CO2 was revealed, although their unit cell size was similar. The δ13C of hydrate-bound CO2 was lower than that of the residual CO2 (1.0–1.5‰) in a formation temperature ranging between 226 K and 278 K. The results show that the small difference between equilibrium pressures of ~0.01 MPa in 12CO2 and 13CO2 hydrates causes carbon isotope fractionation of ~1‰. However, the difference between equilibrium pressures in the 12CO2–H2O and 13CO2–H2O systems was smaller than the standard uncertainties of measurement; more accurate pressure measurement is required for quantitative discussion.
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10
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Chen M, Liu S, Xu GX, Shi ZM. [Vertical distribution of natural abundance of stable carbon and nitrogen isotopes along the soil profile and the underlying mechanisms]. Ying Yong Sheng Tai Xue Bao 2021; 32:1919-1927. [PMID: 34212595 DOI: 10.13287/j.1001-9332.202106.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Understanding the changes of natural abundance of stable carbon and nitrogen isotopes (δ13C and δ15N) along soil profile is of great importance in revealing the mechanisms of soil carbon and nitrogen cycling in terrestrial ecosystems. Based on a comprehensive review on the distribution of δ13C and δ15N along soil profile, the mechanisms underlying their vertical distribution were mainly introduced here. There were three mechanisms driving the δ13C vertical distribution in soil profile: 1) historical changes of vegetation δ13C value, 2) changes of C3-C4 species dominance in plant communities, 3) accumulation of 13C-enriched microbial-derived carbon during decomposition. The effects of 13C Suess effect on the vertical distribution of δ13C in soil profile were also discussed. There were four mechanisms underlying the vertical distribution of δ15N in soil profile: 1) 15N-depletion gas loss during denitrification, 2) accumulation of 15N-enriched microbial-derived nitrogen during decomposition, 3) accumulation of 15N-encriched mycorrhizal fungi residues in deep soil as a result of transferring 15N-depleted nitrogen compounds to plants by mycorrhizae, 4) intera-ction between soil organic matter and mineral substance. We proposed important concerning points for the future study on vertical distribution of natural abundance of stable carbon and nitrogen isotopes in soil profile.
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Affiliation(s)
- Miao Chen
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China.,Miyaluo Research Station of Alpine Forest Ecosystem, Lixian 623100, Sichuan, China
| | - Shun Liu
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China.,Miyaluo Research Station of Alpine Forest Ecosystem, Lixian 623100, Sichuan, China
| | - Ge-Xi Xu
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China.,Miyaluo Research Station of Alpine Forest Ecosystem, Lixian 623100, Sichuan, China
| | - Zuo-Min Shi
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China.,Miyaluo Research Station of Alpine Forest Ecosystem, Lixian 623100, Sichuan, China.,Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
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11
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Kotajima S, Koba K, Ikeda D, Terada A, Isaka K, Nishina K, Kimura Y, Makabe A, Yano M, Fujitani H, Ushiki N, Tsuneda S, Yoh M. Nitrogen and Oxygen Isotope Signatures of Nitrogen Compounds during Anammox in the Laboratory and a Wastewater Treatment Plant. Microbes Environ 2020; 35. [PMID: 33162466 PMCID: PMC7734408 DOI: 10.1264/jsme2.me20031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Isotopic fractionation factors against 15N and 18O during anammox (anaerobic ammonia oxidization by nitrite) are critical for evaluating the importance of this process in natural environments. We performed batch incubation experiments with an anammox-dominated biomass to investigate nitrogen (N) and oxygen (O) isotopic fractionation factors during anammox and also examined apparent isotope fractionation factors during anammox in an actual wastewater treatment plant. We conducted one incubation experiment with high δ18O of water to investigate the effects of water δ18O. The N isotopic fractionation factors estimated from incubation experiments and the wastewater treatment plant were similar to previous values. We also found that the N isotopic effect (15εNXR of -77.8 to -65.9‰ and 15ΔNXR of -31.3 to -30.4‰) and possibly O isotopic effect (18εNXR of -20.6‰) for anaerobic nitrite oxidation to nitrate were inverse. We applied the estimated isotopic fractionation factors to the ordinary differential equation model to clarify whether anammox induces deviations in the δ18O vs δ15N of nitrate from a linear trajectory of 1, similar to heterotrophic denitrification. Although this deviation has been attributed to nitrite oxidation, the O isotopic fractionation factor for anammox is crucial for obtaining a more detailed understanding of the mechanisms controlling this deviation. In our model, anammox induced the trajectory of the δ18O vs δ15N of nitrate during denitrification to less than one, which strongly indicates that this deviation is evidence of nitrite oxidation by anammox under denitrifying conditions.
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Affiliation(s)
- Shotoku Kotajima
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology
| | - Keisuke Koba
- Center for Ecological Research, Kyoto University.,Institute of Agriculture, Tokyo University of Agriculture and Technology
| | - Daisuke Ikeda
- Graduate School of Engineering, Tokyo University of Agriculture and Technology
| | - Akihiko Terada
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology.,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology
| | - Kazuichi Isaka
- Hitachi, Ltd.,Department of Applied Chemistry, Faculty of Science and Engineering, Toyo University
| | - Kazuya Nishina
- Center for Regional Environmental Research, National Institute of Environmental Sciences
| | | | - Akiko Makabe
- Institute of Agriculture, Tokyo University of Agriculture and Technology.,Project Team for Development of New-generation Research Protocol for Submarine Resources, Japan Agency for Marine-Earth Science and Technology.,Present address: Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Super-cutting-edge Grand and Advanced Research (SUGAR) Program, Japan Agency for Marine-Earth Science and Technology
| | - Midori Yano
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology.,Center for Ecological Research, Kyoto University
| | - Hirotsugu Fujitani
- Department of Life Science and Medical Bioscience, Waseda University.,Present address: Department of Biological Sciences, Faculty of Science and Engineering, Chuo University
| | - Norisuke Ushiki
- Department of Life Science and Medical Bioscience, Waseda University
| | - Satoshi Tsuneda
- Department of Life Science and Medical Bioscience, Waseda University
| | - Muneoki Yoh
- Institute of Agriculture, Tokyo University of Agriculture and Technology
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12
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Han S, Gunthardt CE, Dawes R, Xie D, North SW, Guo H. Origin of the "odd" behavior in the ultraviolet photochemistry of ozone. Proc Natl Acad Sci U S A 2020; 117:21065-9. [PMID: 32817468 DOI: 10.1073/pnas.2006070117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The origin of the even-odd rotational state population alternation in the 16O2(a 1Δg) fragments resulting from the ultraviolet (UV) photodissociation of 16O3, a phenomenon first observed over 30 years ago, has been elucidated using full quantum theory. The calculated 16O2(a 1Δg) rotational state distribution following the 266-nm photolysis of 60 K ozone shows a strong even-odd propensity, in excellent agreement with the new experimental rotational state distribution measured under the same conditions. Theory indicates that the even rotational states are significantly more populated than the adjacent odd rotational states because of a preference for the formation of the A' Λ-doublet, which can only occupy even rotational states due to the exchange symmetry of the two bosonic 16O nuclei, and thus not as a result of parity-selective curve crossing as previously proposed. For nonrotating ozone, its dissociation on the excited B1A' state dictates that only A' Λ-doublets are populated, due to symmetry conservation. This selection rule is relaxed for rotating parent molecules, but a preference still persists for A' Λ-doublets. The A''/A' ratio increases with increasing ozone rotational quantum number, and thus with increasing temperature, explaining the previously observed temperature dependence of the even-odd population alternation. In light of these results, it is concluded that the previously proposed parity-selective curve-crossing mechanism cannot be a source of heavy isotopic enrichment in the atmosphere.
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13
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Nuche‐Pascual MT, Lazo JP, Ruiz‐Cooley RI, Herzka SZ. Amino acid-specific δ 15N trophic enrichment factors in fish fed with formulated diets varying in protein quantity and quality. Ecol Evol 2018; 8:9192-9217. [PMID: 30377494 PMCID: PMC6194260 DOI: 10.1002/ece3.4295] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 05/07/2018] [Accepted: 05/20/2018] [Indexed: 11/10/2022] Open
Abstract
Compound-specific isotope analysis (CSIA) of amino acids (AAs) in consumer tissues is a developing technique with wide-ranging applications for identifying nitrogen (N) sources and estimating animal trophic level. Controlled experiments are essential for determining which dietary conditions influence variability in N stable isotopes (δ15N) trophic enrichment factors in bulk tissue (TEFbulk) and AAs (TEFAA). To date, however, studies have not independently evaluated the effect of protein quantity and quality (digestibility) on TEFs, complicating the application of AA-δ15N values for estimating trophic levels. We conducted a 98-d feeding experiment using five formulated isoenergetic feeds prepared with a high-quality protein source to evaluate the effect of protein quantity and quality on TEFs of liver and muscle tissues of juvenile Pacific yellowtail (Seriola lalandi), a carnivorous fish species. We decreased protein digestibility using well-established protocols that do not change AA profiles. Growth rates were higher in diets with higher protein content, and isotopic equilibrium was reached for both fish tissues and all treatments. Protein quantity and quality influenced isotope discrimination depending on tissue type and AA. In liver tissue, bulk TEFs showed a limited but significant relationship with protein quality, but did not differ with protein quantity or quality in muscle. None of the pre-established source AAs (Lys, Met, Phe, and Gly) TEFs varied significantly with protein quantity or quality in liver tissue. However, in muscle tissue, TEFPhe increased significantly with protein content and decreased in response to reduced digestibility, indicating it may not serve as proxy for baseline isotopic values used to calculate trophic level. Among trophic AAs, TEFLeu decreased significantly with increasing protein quantity in liver tissue, while both Leu and Ile TEFs decreased with lower protein digestibility in muscle tissue. Our results indicate that CSIA-AA in liver tissue provides more robust source and trophic AA-δ15N values than in muscle.
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Affiliation(s)
- M. Teresa Nuche‐Pascual
- Departamento de Oceanografía BiológicaCentro de Investigación Científica y de Educación Superior de Ensenada (CICESE)EnsenadaMéxico
| | | | | | - Sharon Z. Herzka
- Departamento de Oceanografía BiológicaCentro de Investigación Científica y de Educación Superior de Ensenada (CICESE)EnsenadaMéxico
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14
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Lamb KD, Clouser BW, Bolot M, Sarkozy L, Ebert V, Saathoff H, Möhler O, Moyer EJ. Laboratory measurements of HDO/H 2O isotopic fractionation during ice deposition in simulated cirrus clouds. Proc Natl Acad Sci U S A 2017; 114:5612-7. [PMID: 28495968 DOI: 10.1073/pnas.1618374114] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The stable isotopologues of water have been used in atmospheric and climate studies for over 50 years, because their strong temperature-dependent preferential condensation makes them useful diagnostics of the hydrological cycle. However, the degree of preferential condensation between vapor and ice has never been directly measured at temperatures below 233 K (-40 °C), conditions necessary to form cirrus clouds in the Earth's atmosphere, routinely observed in polar regions, and typical for the near-surface atmospheric layers of Mars. Models generally assume an extrapolation from the warmer experiments of Merlivat and Nief [Merlivat L, Nief G (1967) Tellus 19:122-127]. Nonequilibrium kinetic effects that should alter preferential partitioning have also not been well characterized experimentally. We present here direct measurements of HDO/H2O equilibrium fractionation between vapor and ice ([Formula: see text]) at cirrus-relevant temperatures, using in situ spectroscopic measurements of the evolving isotopic composition of water vapor during cirrus formation experiments in a cloud chamber. We rule out the recent proposed upward modification of [Formula: see text], and find values slightly lower than Merlivat and Nief. These experiments also allow us to make a quantitative validation of the kinetic modification expected to occur in supersaturated conditions in the ice-vapor system. In a subset of diffusion-limited experiments, we show that kinetic isotope effects are indeed consistent with published models, including allowing for small surface effects. These results are fundamental for inferring processes on Earth and other planets from water isotopic measurements. They also demonstrate the utility of dynamic in situ experiments for studying fractionation in geochemical systems.
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15
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Takizawa Y, Dharampal PS, Steffan SA, Takano Y, Ohkouchi N, Chikaraishi Y. Intra-trophic isotopic discrimination of 15N/ 14N for amino acids in autotrophs: Implications for nitrogen dynamics in ecological studies. Ecol Evol 2017; 7:2916-2924. [PMID: 28479991 PMCID: PMC5415530 DOI: 10.1002/ece3.2866] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 02/01/2017] [Accepted: 02/06/2017] [Indexed: 11/13/2022] Open
Abstract
The differential discrimination of nitrogen isotopes (15N/14N) within amino acids in consumers and their diets has been routinely used to estimate organismal tropic position (TP). Analogous isotopic discrimination can occur within plants, particularly in organs lacking chloroplasts. Such discrimination likely arises from the catabolic deamination of amino acids, resulting in a numerical elevation of estimated TP, within newly synthesized biomass. To investigate this phenomenon, we examined the 15N/14N of amino acids (δ15 NAA) in spring leaves and flowers from eight deciduous and two annual plants. These plants were classified on the basis of their time of bloom, plants that bloomed when their leaves were absent (Type I) versus plants that bloomed while leaves were already present (Type II). Based on the δ15 NAA values from leaves, both plant types occupied comparable and ecologically realistic mean TPs (=1.0 ± 0.1, mean ± 1σ). However, the estimated TPs of flowers varied significantly (Type I: 2.2 ± 0.2; Type II: 1.0 ± 0.1). We hypothesize that these results can be interpreted by the following sequence of events: (1) Type I floral biomass is synthesized in absence of active photosynthesis; (2) the catabolic deamination of amino acids in particular, leaves behind 15N in the residual pool of amino acids; and (3) the incorporation of these 15N-enriched amino acids within the biomass of Type I flowers results in the numerical elevation of the TPs. In contrast, the actively photosynthesizing Type II leaves energetically sustain the synthesis of Type II flower biomass, precluding any reliance on catabolic deamination of amino acids. Amino acids within Type II flowers are therefore isotopically comparable to the Type II leaves. These findings demonstrate the idiosyncratic nature of the δ15 NAA values within autotrophic organs and have implications for interpreting trophic hierarchies using primary producers and their consumers.
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Affiliation(s)
- Yuko Takizawa
- Faculty of Environmental Earth Science Hokkaido University Sapporo Japan
- Institute of Low Temperature Science Hokkaido University Sapporo Japan
- Japan Agency for Marine-Earth Science and Technology Yokosuka Japan
| | | | - Shawn A Steffan
- Department of Entomology University of Wisconsin Madison WI USA
- US Department of Agriculture Agricultural Research Service Madison WI USA
| | - Yoshinori Takano
- Japan Agency for Marine-Earth Science and Technology Yokosuka Japan
| | - Naohiko Ohkouchi
- Japan Agency for Marine-Earth Science and Technology Yokosuka Japan
| | - Yoshito Chikaraishi
- Institute of Low Temperature Science Hokkaido University Sapporo Japan
- Japan Agency for Marine-Earth Science and Technology Yokosuka Japan
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16
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Paredes E, Avazeri E, Malard V, Vidaud C, Reiller PE, Ortega R, Nonell A, Isnard H, Chartier F, Bresson C. Evidence of isotopic fractionation of natural uranium in cultured human cells. Proc Natl Acad Sci U S A 2016; 113:14007-12. [PMID: 27872304 DOI: 10.1073/pnas.1610885113] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The study of the isotopic fractionation of endogen elements and toxic heavy metals in living organisms for biomedical applications, and for metabolic and toxicological studies, is a cutting-edge research topic. This paper shows that human neuroblastoma cells incorporated small amounts of uranium (U) after exposure to 10 µM natural U, with preferential uptake of the 235U isotope with regard to 238U. Efforts were made to develop and then validate a procedure for highly accurate n(238U)/n(235U) determinations in microsamples of cells. We found that intracellular U is enriched in 235U by 0.38 ± 0.13‰ (2σ, n = 7) relative to the exposure solutions. These in vitro experiments provide clues for the identification of biological processes responsible for uranium isotopic fractionation and link them to potential U incorporation pathways into neuronal cells. Suggested incorporation processes are a kinetically controlled process, such as facilitated transmembrane diffusion, and the uptake through a high-affinity uranium transport protein involving the modification of the uranyl (UO22+) coordination sphere. These findings open perspectives on the use of isotopic fractionation of metals in cellular models, offering a probe to track uptake/transport pathways and to help decipher associated cellular metabolic processes.
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17
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Abstract
The emerging interest in using stable bedrock formations for industrial purposes, e.g., nuclear waste disposal, has increased the need for understanding microbiological and geochemical processes in deep crystalline rock environments, including the carbon cycle. Considering the origin and evolution of life on Earth, these environments may also serve as windows to the past. Various geological, chemical, and biological processes can influence the deep carbon cycle. Conditions of CH4 formation, available substrates and time scales can be drastically different from surface environments. This paper reviews the origin, source, and cycling of methane in deep terrestrial crystalline bedrock with an emphasis on microbiology. In addition to potential formation pathways of CH4, microbial consumption of CH4 is also discussed. Recent studies on the origin of CH4 in continental bedrock environments have shown that the traditional separation of biotic and abiotic CH4 by the isotopic composition can be misleading in substrate-limited environments, such as the deep crystalline bedrock. Despite of similarities between Precambrian continental sites in Fennoscandia, South Africa and North America, where deep methane cycling has been studied, common physicochemical properties which could explain the variation in the amount of CH4 and presence or absence of CH4 cycling microbes were not found. However, based on their preferred carbon metabolism, methanogenic microbes appeared to have similar spatial distribution among the different sites.
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Affiliation(s)
| | - Lotta Purkamo
- VTT Technical Research Centre of Finland Espoo, Finland
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18
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Fairén AG, Losa-Adams E, Gil-Lozano C, Gago-Duport L, Uceda ER, Squyres SW, Rodríguez JAP, Davila AF, McKay CP. Tracking the weathering of basalts on Mars using lithium isotope fractionation models. Geochem Geophys Geosyst 2015; 16:1172-1197. [PMID: 27642264 PMCID: PMC5008203 DOI: 10.1002/2015gc005748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 03/24/2015] [Indexed: 06/06/2023]
Abstract
Lithium (Li), the lightest of the alkali elements, has geochemical properties that include high aqueous solubility (Li is the most fluid mobile element) and high relative abundance in basalt-forming minerals (values ranking between 0.2 and 12 ppm). Li isotopes are particularly subject to fractionation because the two stable isotopes of lithium-7Li and 6Li-have a large relative mass difference (∼15%) that results in significant fractionation between water and solid phases. The extent of Li isotope fractionation during aqueous alteration of basalt depends on the dissolution rate of primary minerals-the source of Li-and on the precipitation kinetics, leading to formation of secondary phases. Consequently, a detailed analysis of Li isotopic ratios in both solution and secondary mineral lattices could provide clues about past Martian weathering conditions, including weathering extent, temperature, pH, supersaturation, and evaporation rate of the initial solutions in contact with basalt rocks. In this paper, we discuss ways in which Martian aqueous processes could have lead to Li isotope fractionation. We show that Li isotopic data obtained by future exploration of Mars could be relevant to highlighting different processes of Li isotopic fractionation in the past, and therefore to understanding basalt weathering and environmental conditions early in the planet's history.
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Affiliation(s)
- Alberto G Fairén
- Centro de Astrobiología Madrid Spain; Department of Astronomy Cornell University Ithaca New York USA
| | | | | | - Luis Gago-Duport
- Departamento de Geociencias Marinas Universidad de Vigo Vigo Spain
| | - Esther R Uceda
- Departamento de Biología Molecular Universidad Autónoma de Madrid Madrid Spain
| | | | - J Alexis P Rodríguez
- Space Science and Astrobiology Division NASA Ames Research Center Mountain View California USA
| | | | - Christopher P McKay
- Space Science and Astrobiology Division NASA Ames Research Center Mountain View California USA
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19
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Chalk PM, Inácio CT, Urquiaga S, Chen D. 13C isotopic fractionation during biodegradation of agricultural wastes. Isotopes Environ Health Stud 2015; 51:201-213. [PMID: 25768051 DOI: 10.1080/10256016.2015.1019488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Significant differences in δ(13)C signatures occur within and between plant tissues and their constituent biochemical entities, and also within and between heterotrophic bacteria and fungi and their metabolic products. Furthermore, (13)C isotopic fractionation occurs during the biodegradation of organic molecules as seen in the substrate, respired CO(2) and the microbial biomass, which could be related to substrate composition and/or microbial metabolism. The (13)C isotopic fractionation observed during the decomposition of a single defined C substrate appears to be due to the intra-molecular heterogeneity in (13)C in the substrate and to (13)C isotopic fractionation during microbial metabolism. Very limited data suggest that the latter may be quantitatively more important than the former. Studies with defined fungi in culture media have highlighted the complexities associated with the interpretation of the observed patterns of (13)C isotopic fractionation when a single defined C source is added to the culture medium which itself contains one or more C sources. Techniques involving (13)C enrichment or paired treatments involving an equivalent C(3)- and C(4)-derived substrate have been devised to overcome the problem of background C in the culture medium and (13)C isotopic fractionation during metabolism. Studies with complex substrates have shown an initial (13)C depletion phase in respired CO(2) followed by a (13)C enrichment phase which may or may not be followed by another (13)C depletion phase. Basic studies involving an integrated approach are required to gain a new insight into (13)C isotopic fractionation during organic residue decomposition, by simultaneous measurements of δ(13)C in all C moieties. New analytical tools to measure real-time changes in δ(13)CO(2) and the intra-molecular δ(13)C distribution within plant biochemical entities offer new opportunities for unravelling the complex interactions between substrate and microbial metabolism with respect to (13)C isotopic fractionation during biodegradation.
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Affiliation(s)
- Phillip M Chalk
- a Faculty of Veterinary and Agricultural Sciences , University of Melbourne , Victoria , Australia
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20
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Ochoa-Izaguirre MJ, Soto-Jiménez MF. Variability in nitrogen stable isotope ratios of macroalgae: consequences for the identification of nitrogen sources. J Phycol 2015; 51:46-65. [PMID: 26986258 DOI: 10.1111/jpy.12250] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 07/30/2014] [Indexed: 06/05/2023]
Abstract
In our research, we collected and analyzed numerous macroalgal specimens (738) for isotopic analysis sampled over a year at monthly intervals across 20 sites within the Urías lagoon complex, a typical subtropical coastal ecosystem located in the Gulf of California. We quantified and characterized (chemically and isotopically) the N loads received by Urías throughout a year. We studied the spatial-temporal variation of the chemical forms and isotopic signals of the available N in the water column, and we monitored in situ different environmental variables and other hydrodynamic parameters. Multiple N sources (e.g., atmospheric, sewage, seafood processing, agriculture and aquaculture effluents) and biogeochemical reactions related to the N cycle (e.g., ammonia volatilization, nitrification and denitrification) co-occurring across the ecosystem, result in a mixture of chemical species and isotopic compositions of available N in the water column. Increased variability was observed in the δ(15) N values of macroalgae (0.41‰-22.67‰). Based on our results, the variation in δ(15) N was best explained by spatio-temporal changes in available N and not necessarily related to the N sources. The variability was also explained by the differences in macroalgal biology among functional groups, species and/or individuals. Although the δ(15) N-macroalgae technique was a useful tool to identify N sources, its application in coastal ecosystems receiving multiple N sources, with changing environmental conditions influencing biogeochemical processes, and high diversity of ephemeral macroalgal species, could be less sensitive and have less predictive power.
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Affiliation(s)
- María Julia Ochoa-Izaguirre
- Posgrado en Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Unidad Académica Mazatlán, Apdo. Postal 811, Mazatlán, Sinaloa, 82040, México
- Facultad de Ciencias del Mar, Universidad Autónoma de Sinaloa, Paseo Claussen s/n, Apdo. Postal 610, Mazatlán, Sinaloa, 82000, México
| | - Martín F Soto-Jiménez
- Unidad Académica Mazatlán, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México (UAM-ICMyL-UNAM), Apdo. Postal 811, Mazatlán, Sinaloa, 82040, México
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21
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Nygren P, Leblanc HA. Dinitrogen fixation by legume shade trees and direct transfer of fixed N to associated cacao in a tropical agroforestry system. Tree Physiol 2015; 35:134-147. [PMID: 25618898 DOI: 10.1093/treephys/tpu116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Natural abundance of (15)N (δ (15)N) was determined in bulk soil, rhizospheric soil and vegetation in an organically managed cacao (Theobroma cacao L.) plantation with Inga edulis Mart. legume trees (inga) as the principal shade for studying the nitrogen (N) cycle in the system. Cacao without contact with legumes in an adjacent plantation was used as the reference for N2 fixation and direct N transfer calculations. Bulk and rhizospheric soils contained 72 and 20%, respectively, of whole- system N. No vegetation effect on δ (15)N in rhizospheric soil was detected, probably due to the high native soil N pool. Fine roots of the cacaos associated with inga contained ∼35% of N fixed from the atmosphere (Nf) out of the total N. Leaves of all species had significantly higher δ (15)N than fine roots. Twenty percent of system Nf was found in cacao suggesting direct N transfer from inga via a common mycelial network of mycorrhizal fungi or recycling of N-rich root exudates of inga. Inga had accumulated 98 kg [Nf] ha(-1) during the 14-year history of the plantation. The conservative estimate of current N2 fixation rate was 41 kg [Nf] ha(-1) year(-1) based on inga biomass only and 50 kg [Nf] ha(-1) year(-1) based on inga and associated trees.
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Affiliation(s)
- Pekka Nygren
- Department of Forest Science PO Box 27, 00014 University of Helsinki Finland Current address: Finnish Society of Forest Science, PO Box 18, 01301 Vantaa Finland
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22
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Day JMD, Moynier F. Evaporative fractionation of volatile stable isotopes and their bearing on the origin of the Moon. Philos Trans A Math Phys Eng Sci 2014; 372:20130259. [PMID: 25114311 PMCID: PMC4128272 DOI: 10.1098/rsta.2013.0259] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The Moon is depleted in volatile elements relative to the Earth and Mars. Low abundances of volatile elements, fractionated stable isotope ratios of S, Cl, K and Zn, high μ ((238)U/(204)Pb) and long-term Rb/Sr depletion are distinguishing features of the Moon, relative to the Earth. These geochemical characteristics indicate both inheritance of volatile-depleted materials that formed the Moon and planets and subsequent evaporative loss of volatile elements that occurred during lunar formation and differentiation. Models of volatile loss through localized eruptive degassing are not consistent with the available S, Cl, Zn and K isotopes and abundance data for the Moon. The most probable cause of volatile depletion is global-scale evaporation resulting from a giant impact or a magma ocean phase where inefficient volatile loss during magmatic convection led to the present distribution of volatile elements within mantle and crustal reservoirs. Problems exist for models of planetary volatile depletion following giant impact. Most critically, in this model, the volatile loss requires preferential delivery and retention of late-accreted volatiles to the Earth compared with the Moon. Different proportions of late-accreted mass are computed to explain present-day distributions of volatile and moderately volatile elements (e.g. Pb, Zn; 5 to >10%) relative to highly siderophile elements (approx. 0.5%) for the Earth. Models of early magma ocean phases may be more effective in explaining the volatile loss. Basaltic materials (e.g. eucrites and angrites) from highly differentiated airless asteroids are volatile-depleted, like the Moon, whereas the Earth and Mars have proportionally greater volatile contents. Parent-body size and the existence of early atmospheres are therefore likely to represent fundamental controls on planetary volatile retention or loss.
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Affiliation(s)
- James M D Day
- Scripps Isotope Geochemistry Laboratory, Geosciences Research Division, Scripps Institution of Oceanography, La Jolla, CA 92093-0244, USA
| | - Frederic Moynier
- Institut de Physique du Globe de Paris, Université Paris Diderot, Sorbonne Paris Cité, 1 rue Jussieu, 75005 Paris, France
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Liu XY, Koba K, Makabe A, Liu CQ. Nitrate dynamics in natural plants: insights based on the concentration and natural isotope abundances of tissue nitrate. Front Plant Sci 2014; 5:355. [PMID: 25101106 PMCID: PMC4108036 DOI: 10.3389/fpls.2014.00355] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 07/03/2014] [Indexed: 05/22/2023]
Abstract
The dynamics of nitrate (NO(-) 3), a major nitrogen (N) source for natural plants, has been studied mostly through experimental N addition, enzymatic assay, isotope labeling, and genetic expression. However, artificial N supply may not reasonably reflect the N strategies in natural plants because NO(-) 3 uptake and reduction may vary with external N availability. Due to abrupt application and short operation time, field N addition, and isotopic labeling hinder the elucidation of in situ NO(-) 3-use mechanisms. The concentration and natural isotopes of tissue NO(-) 3 can offer insights into the plant NO(-) 3 sources and dynamics in a natural context. Furthermore, they facilitate the exploration of plant NO(-) 3 utilization and its interaction with N pollution and ecosystem N cycles without disturbing the N pools. The present study was conducted to review the application of the denitrifier method for concentration and isotope analyses of NO(-) 3 in plants. Moreover, this study highlights the utility and advantages of these parameters in interpreting NO(-) 3 sources and dynamics in natural plants. We summarize the major sources and reduction processes of NO(-) 3 in plants, and discuss the implications of NO(-) 3 concentration in plant tissues based on existing data. Particular emphasis was laid on the regulation of soil NO(-) 3 and plant ecophysiological functions in interspecific and intra-plant NO(-) 3 variations. We introduce N and O isotope systematics of NO(-) 3 in plants and discuss the principles and feasibilities of using isotopic enrichment and fractionation factors; the correlation between concentration and isotopes (N and O isotopes: δ(18)O and Δ(17)O); and isotope mass-balance calculations to constrain sources and reduction of NO(-) 3 in possible scenarios for natural plants are deliberated. Finally, we offer a preliminary framework of intraplant δ(18)O-NO(-) 3 variation, and summarize the uncertainties in using tissue NO(-) 3 parameters to interpret plant NO(-) 3 utilization.
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Affiliation(s)
- Xue-Yan Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of SciencesGuiyang, China
- Department of Environmental Science on Biosphere, Institute of Agriculture, Tokyo University of Agriculture and TechnologyFuchu, Japan
| | - Keisuke Koba
- Department of Environmental Science on Biosphere, Institute of Agriculture, Tokyo University of Agriculture and TechnologyFuchu, Japan
| | - Akiko Makabe
- Department of Environmental Science on Biosphere, Institute of Agriculture, Tokyo University of Agriculture and TechnologyFuchu, Japan
| | - Cong-Qiang Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of SciencesGuiyang, China
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Streit K, Siegwolf RTW, Hagedorn F, Schaub M, Buchmann N. Lack of photosynthetic or stomatal regulation after 9 years of elevated [CO2] and 4 years of soil warming in two conifer species at the alpine treeline. Plant Cell Environ 2014; 37:315-326. [PMID: 24003840 DOI: 10.1111/pce.12197] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Alpine treelines are temperature-limited vegetation boundaries. Understanding the effects of elevated [CO2 ] and warming on CO2 and H2 O gas exchange may help predict responses of treelines to global change. We measured needle gas exchange of Larix decidua Mill. and Pinus mugo ssp. uncinata DC trees after 9 years of free air CO2 enrichment (575 µmol mol(-1) ) and 4 years of soil warming (+4 °C) and analysed δ(13) C and δ(18) O values of needles and tree rings. Tree needles under elevated [CO2 ] showed neither nitrogen limitation nor end-product inhibition, and no down-regulation of maximal photosynthetic rate (Amax ) was found. Both tree species showed increased net photosynthetic rates (An ) under elevated [CO2 ] (L. decidua: +39%; P. mugo: +35%). Stomatal conductance (gH2O ) was insensitive to changes in [CO2 ], thus transpiration rates remained unchanged and intrinsic water-use efficiency (iWUE) increased due to higher An . Soil warming affected neither An nor gH2O . Unresponsiveness of gH2O to [CO2 ] and warming was confirmed by δ(18) O needle and tree ring values. Consequently, under sufficient water supply, elevated [CO2 ] induced sustained enhancement in An and lead to increased C inputs into this ecosystem, while soil warming hardly affected gas exchange of L. decidua and P. mugo at the alpine treeline.
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Affiliation(s)
- Kathrin Streit
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), 5232, Villigen, Switzerland
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Casciotti KL, Buchwald C. Insights on the marine microbial nitrogen cycle from isotopic approaches to nitrification. Front Microbiol 2012; 3:356. [PMID: 23091468 PMCID: PMC3469838 DOI: 10.3389/fmicb.2012.00356] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2012] [Accepted: 09/18/2012] [Indexed: 11/20/2022] Open
Abstract
The microbial nitrogen (N) cycle involves a variety of redox processes that control the availability and speciation of N in the environment and that are involved with the production of nitrous oxide (N2O), a climatically important greenhouse gas. Isotopic measurements of ammonium (NH+4), nitrite (NO−2), nitrate (NO−3), and N2O can now be used to track the cycling of these compounds and to infer their sources and sinks, which has lead to new and exciting discoveries. For example, dual isotope measurements of NO−3 and NO−2 have shown that there is NO−3 regeneration in the ocean's euphotic zone, as well as in and around oxygen deficient zones (ODZs), indicating that nitrification may play more roles in the ocean's N cycle than generally thought. Likewise, the inverse isotope effect associated with NO−2 oxidation yields unique information about the role of this process in NO−2 cycling in the primary and secondary NO−2 maxima. Finally, isotopic measurements of N2O in the ocean are indicative of an important role for nitrification in its production. These interpretations rely on knowledge of the isotope effects for the underlying microbial processes, in particular ammonia oxidation and nitrite oxidation. Here we review the isotope effects involved with the nitrification process and the insights provided by this information, then provide a prospectus for future work in this area.
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Affiliation(s)
- Karen L Casciotti
- Department of Environmental Earth System Science, Stanford University Stanford, CA, USA
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Kwon SY, Blum JD, Carvan MJ, Basu N, Head JA, Madenjian CP, David SR. Absence of fractionation of mercury isotopes during trophic transfer of methylmercury to freshwater fish in captivity. Environ Sci Technol 2012; 46:7527-34. [PMID: 22681311 PMCID: PMC4347840 DOI: 10.1021/es300794q] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We performed two controlled experiments to determine the amount of mass-dependent and mass-independent fractionation (MDF and MIF) of methylmercury (MeHg) during trophic transfer into fish. In experiment 1, juvenile yellow perch (Perca flavescens) were raised in captivity on commercial food pellets and then their diet was either maintained on unamended food pellets (0.1 μg/g MeHg) or was switched to food pellets with 1.0 μg/g or 4.0 μg/g of added MeHg, for a period of 2 months. The difference in δ(202)Hg (MDF) and Δ(199)Hg (MIF) between fish tissues and food pellets with added MeHg was within the analytical uncertainty (δ(202)Hg, 0.07 ‰; Δ(199)Hg, 0.06 ‰), indicating no isotope fractionation. In experiment 2, lake trout (Salvelinus namaycush) were raised in captivity on food pellets and then shifted to a diet of bloater (Coregonus hoyi) for 6 months. The δ(202)Hg and Δ(199)Hg of the lake trout equaled the isotopic composition of the bloater after 6 months, reflecting reequilibration of the Hg isotopic composition of the fish to new food sources and a lack of isotope fractionation during trophic transfer. We suggest that the stable Hg isotope ratios in fish can be used to trace environmental sources of Hg in aquatic ecosystems.
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Affiliation(s)
- Sae Yun Kwon
- Department of Earth and Environmental Sciences, University of Michigan, 1100 N. University Avenue, Ann Arbor, Michigan 48109, United States.
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De Carvalho MC, Hayashizaki KI, Ogawa H. SHORT-TERM MEASUREMENT OF CARBON STABLE ISOTOPE DISCRIMINATION IN PHOTOSYNTHESIS AND RESPIRATION BY AQUATIC MACROPHYTES, WITH MARINE MACROALGAL EXAMPLES(1). J Phycol 2009; 45:761-770. [PMID: 27034051 DOI: 10.1111/j.1529-8817.2009.00685.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Progress in the study of stable isotope discrimination in carbon assimilation by aquatic macrophytes has been slower than for other groups of primary producers, such as phytoplankton and terrestrial plants. A probable reason has been the methodologies employed for such a study: field collections or long-term incubations, both relying on the observation of changes in carbon isotope composition of plant tissue. Here, we present a short-term incubation method based on the change in carbon stable isotope composition in water. Its fundamental advantage over the other approaches is that the change in stable isotope composition in water in a closed system is much faster than in the plant tissue. We applied the method to investigate the relationship between carbon assimilation intensity and isotope discrimination. The results included a relatively small discrimination in respiration, a significant influence of carbon assimilation rate on discrimination, and the suggestion of HCO3 (-) or CO2 uptake in photosynthesis. The information gathered using this method would be difficult to obtain in other ways, and so we believe that it should contribute to a better understanding of the physiology and ecology of aquatic macrophytes.
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Affiliation(s)
| | - Ken-Ichi Hayashizaki
- School of Marine Biosciences, Kitasato University, Sanriku-cho, Ofunato, Iwate 022-0101, Japan
| | - Hisao Ogawa
- School of Marine Biosciences, Kitasato University, Sanriku-cho, Ofunato, Iwate 022-0101, Japan
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