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Journal articles on the topic 'Carbon isotope fractionation'

Author: Grafiati

Published: 2 June 2025

Last updated: 31 July 2025

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1

Meister, Patrick, and Carolina Reyes. "The Carbon-Isotope Record of the Sub-Seafloor Biosphere." Geosciences 9, no. 12 (2019): 507. http://dx.doi.org/10.3390/geosciences9120507.

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Sub-seafloor microbial environments exhibit large carbon-isotope fractionation effects as a result of microbial enzymatic reactions. Isotopically light, dissolved inorganic carbon (DIC) derived from organic carbon is commonly released into the interstitial water due to microbial dissimilatory processes prevailing in the sub-surface biosphere. Much stronger carbon-isotope fractionation occurs, however, during methanogenesis, whereby methane is depleted in 13C and, by mass balance, DIC is enriched in 13C, such that isotopic distributions are predominantly influenced by microbial metabolisms invo

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2

Erez, Jonathan, Anne Bouevitch, and Aaron Kaplan. "Carbon isotope fractionation by photosynthetic aquatic microorganisms: experiments with Synechococcus PCC7942, and a simple carbon flux model." Canadian Journal of Botany 76, no. 6 (1998): 1109–18. http://dx.doi.org/10.1139/b98-067.

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Stable carbon isotopes (12C and 13C) are widely used to trace biogeochemical processes in the global carbon cycle. Natural fractionation of carbon isotopes is mainly due to the discrimination of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) against 13C during photosynthesis. In marine and other aquatic microorganisms, this fractionation is lowered when the dissolved CO2 (CO2(aq)) is decreasing, but the underlying mechanisms are poorly understood. Cultured Synechococcus PCC7942 showed maximum isotopic fractionations of -33omicron (in delta 13C units) relative to the total inorganic

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Sponheimer, Matt, Todd Robinson, Linda Ayliffe, et al. "An experimental study of carbon-isotope fractionation between diet, hair, and feces of mammalian herbivores." Canadian Journal of Zoology 81, no. 5 (2003): 871–76. http://dx.doi.org/10.1139/z03-066.

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The carbon-isotope composition of hair and feces offers a glimpse into the diets of mammalian herbivores. It is particularly useful for determining the relative consumption of browse and graze in tropical environments, as these foods have strongly divergent carbon-isotope compositions. Fecal δ13C values reflect the last few days consumption, whereas hair provides longer term dietary information. Previous studies have shown, however, that some fractionation occurs between dietary δ13C values and those of hair and feces. Accurate dietary reconstruction requires an understanding of these fraction

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Roth, James D., and Keith A. Hobson. "Stable carbon and nitrogen isotopic fractionation between diet and tissue of captive red fox: implications for dietary reconstruction." Canadian Journal of Zoology 78, no. 5 (2000): 848–52. http://dx.doi.org/10.1139/z00-008.

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The amount of isotopic fractionation (change in isotope ratios) between diet and animal tissues is generally poorly known and may be affected by trophic position. Diet-tissue fractionation of stable-carbon and -nitrogen isotopes was measured in several tissues of red foxes (Vulpes vulpes) raised on a commercial pellet feed. Stable carbon isotopic fractionation in red fox was positive for all tissues and was greatest in fur (2.6), intermediate in muscle (1.1), and least in liver and blood fractions (0.4-0.6). These carbon isotope fractionation values were greater than those previously measur

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Benbow, Timothy J., Alan R. Hayman, Robert Van Hale, and Russell Frew. "Preparation of aqueous fatty acids for hydrogen and carbon stable isotope analysis by solid phase extraction." Marine and Freshwater Research 64, no. 4 (2013): 294. http://dx.doi.org/10.1071/mf12192.

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Stable isotope analyses of fatty acids in environmental waters provides important information as to their source(s). Analysis is often confounded due to low concentrations of fatty acids and/or a complex sample matrix requiring separation of the target analyte. The purpose of this study was to validate a method to extract fatty acids from natural waters using solid phase extraction (SPE) before compound specific isotope analysis (CSIA). Three SPE cartridges and multiple eluting solvents were tested to determine the efficiency, isotopic fractionation, and reproducibility of each extraction tech

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Marentes, E., R. A. Vanderpool, and B. J. Shelp. "Boron-isotope fractionation in plants." Canadian Journal of Plant Science 77, no. 4 (1997): 627–29. http://dx.doi.org/10.4141/p97-010.

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Naturally-occurring variations in the abundance of stable isotopes of carbon, nitrogen, oxygen, and other elements in plants have been reported and are now used to understand various physiological processes in plants. Boron (B) isotopic variation in several plant species has been documented, but no determination as to whether plants fractionate the stable isotopes of boron, 11B and 10B, has been made. Here, we report that plants with differing B requirements (wheat, corn and broccoli) fractionated boron. The whole plant was enriched in 11B relative to the nutrient solution, and the leaves were

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Jahn, A., K. Lindsay, X. Giraud, et al. "Carbon isotopes in the ocean model of the Community Earth System Model (CESM1)." Geoscientific Model Development 8, no. 8 (2015): 2419–34. http://dx.doi.org/10.5194/gmd-8-2419-2015.

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Abstract. Carbon isotopes in the ocean are frequently used as paleoclimate proxies and as present-day geochemical ocean tracers. In order to allow a more direct comparison of climate model results with this large and currently underutilized data set, we added a carbon isotope module to the ocean model of the Community Earth System Model (CESM), containing the cycling of the stable isotope 13C and the radioactive isotope 14C. We implemented the 14C tracer in two ways: in the "abiotic" case, the 14C tracer is only subject to air–sea gas exchange, physical transport, and radioactive decay, while

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Jahn, A., K. Lindsay, X. Giraud, et al. "Carbon isotopes in the ocean model of the Community Earth System Model (CESM1)." Geoscientific Model Development Discussions 7, no. 6 (2014): 7461–503. http://dx.doi.org/10.5194/gmdd-7-7461-2014.

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Abstract. Carbon isotopes in the ocean are frequently used as paleo climate proxies and as present-day geochemical ocean tracers. In order to allow a more direct comparison of climate model results with this large and currently underutilized dataset, we added a carbon isotope module to the ocean model of the Community Earth System Model (CESM), containing the cycling of the stable isotope 13C and the radioactive isotope 14C. We implemented the 14C tracer in two ways: in the "abiotic" case, the 14C tracer is only subject to air–sea gas exchange, physical transport, and radioactive decay, while

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9

Morasch, Barbara, Hans H. Richnow, Bernhard Schink, and Rainer U. Meckenstock. "Stable Hydrogen and Carbon Isotope Fractionation during Microbial Toluene Degradation: Mechanistic and Environmental Aspects." Applied and Environmental Microbiology 67, no. 10 (2001): 4842–49. http://dx.doi.org/10.1128/aem.67.10.4842-4849.2001.

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ABSTRACT Primary features of hydrogen and carbon isotope fractionation during toluene degradation were studied to evaluate if analysis of isotope signatures can be used as a tool to monitor biodegradation in contaminated aquifers. D/H hydrogen isotope fractionation during microbial degradation of toluene was measured by gas chromatography. Per-deuterated toluene-d 8 and nonlabeled toluene were supplied in equal amounts as growth substrates, and kinetic isotope fractionation was calculated from the shift of the molar ratios of toluene-d 8 and nondeuterated toluene. The D/H isotope fractionation

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10

Sare, David T. J., John S. Millar, and Frederick J. Longstaffe. "Tracing dietary protein in red-backed voles (Clethrionomys gapperi) using stable isotopes of nitrogen and carbon." Canadian Journal of Zoology 83, no. 5 (2005): 717–25. http://dx.doi.org/10.1139/z05-064.

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We examined the stable isotopes of nitrogen and carbon in a small mammal, the red-backed vole (Clethroinomys gapperi (Vigors, 1830)), to determine if isotope signatures reflect diet composition. Nitrogen- and carbon-isotope ratios in tissues from voles maintained on different protein levels in the laboratory were compared with wild-trapped voles. The isotopic fractionation of dietary nitrogen and carbon was also examined as food was digested in the stomach, incorporated into bone collagen, bioapatite, and hair, and excreted as feces. Nitrogen and carbon isotopes were fractionated differently d

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Detmers, Jan, Volker Brüchert, Kirsten S. Habicht, and Jan Kuever. "Diversity of Sulfur Isotope Fractionations by Sulfate-Reducing Prokaryotes." Applied and Environmental Microbiology 67, no. 2 (2001): 888–94. http://dx.doi.org/10.1128/aem.67.2.888-894.2001.

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ABSTRACT Batch culture experiments were performed with 32 different sulfate-reducing prokaryotes to explore the diversity in sulfur isotope fractionation during dissimilatory sulfate reduction by pure cultures. The selected strains reflect the phylogenetic and physiologic diversity of presently known sulfate reducers and cover a broad range of natural marine and freshwater habitats. Experimental conditions were designed to achieve optimum growth conditions with respect to electron donors, salinity, temperature, and pH. Under these optimized conditions, experimental fractionation factors ranged

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Glidden, Ana, Sara Seager, Janusz J. Petkowski, and Shuhei Ono. "Can Isotopologues Be Used as Biosignature Gases in Exoplanet Atmospheres?" Life 13, no. 12 (2023): 2325. http://dx.doi.org/10.3390/life13122325.

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Isotopologue ratios are anticipated to be one of the most promising signs of life that can be observed remotely. On Earth, carbon isotopes have been used for decades as evidence of modern and early metabolic processes. In fact, carbon isotopes may be the oldest evidence for life on Earth, though there are alternative geological processes that can lead to the same magnitude of fractionation. However, using isotopologues as biosignature gases in exoplanet atmospheres presents several challenges. Most significantly, we will only have limited knowledge of the underlying abiotic carbon reservoir of

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Blaser, Martin B., Lisa K. Dreisbach, and Ralf Conrad. "Carbon Isotope Fractionation of 11 Acetogenic Strains Grown on H2and CO2." Applied and Environmental Microbiology 79, no. 6 (2012): 1787–94. http://dx.doi.org/10.1128/aem.03203-12.

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ABSTRACTAcetogenic bacteria are able to grow autotrophically on hydrogen and carbon dioxide by using the acetyl coenzyme A (acetyl-CoA) pathway. Acetate is the end product of this reaction. In contrast to the fermentative route of acetate production, which shows almost no fractionation of carbon isotopes, the acetyl-CoA pathway has been reported to exhibit a preference for light carbon. InAcetobacterium woodiithe isotope fractionation factor (ε) for13C and12C has previously been reported to be ε = −58.6‰. To investigate whether such a strong fractionation is a general feature of acetogenic bac

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Doi, Hideyuki, Kwang-Hyeon Chang, and Shin-ichi Nakano. "Nitrogen and carbon isotope fractionations of zooplankton consumers in ponds: potential effects of seston C:N stoichiometry." Marine and Freshwater Research 62, no. 1 (2011): 66. http://dx.doi.org/10.1071/mf10090.

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C : N stoichiometry in food sources is known to influence nitrogen isotope fractionation of consumers, but the relationship between C : N stoichiometry and isotope fractionation has never been tested in the field. In this study, we investigated the effects of the C : N ratio of food sources on nitrogen and carbon isotope fractionation (Δδ15N and Δδ13C) of consumers, using zooplankton communities in 15 ponds in Japan. The fractionation variations we found contradicted the assumption of a 3.4‰ enrichment in δ15N of consumers per trophic level. However, the negative relationships between Δδ15N of

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15

Hunkeler, D., and R. Aravena. "Evidence of Substantial Carbon Isotope Fractionation among Substrate, Inorganic Carbon, and Biomass during Aerobic Mineralization of 1,2-Dichloroethane byXanthobacter autotrophicus." Applied and Environmental Microbiology 66, no. 11 (2000): 4870–76. http://dx.doi.org/10.1128/aem.66.11.4870-4876.2000.

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ABSTRACT Carbon isotope fractionation during aerobic mineralization of 1,2-dichloroethane (1,2-DCA) by Xanthobacter autotrophicusGJ10 was investigated. A strong enrichment of 13C in residual 1,2-DCA was observed, with a mean fractionation factor α ± standard deviation of 0.968 ± 0.0013 to 0.973 ± 0.0015. In addition, a large carbon isotope fractionation between biomass and inorganic carbon occurred. A mechanistic model that links the fractionation factor α to the rate constants of the first catabolic enzyme was developed. Based on the model, it was concluded that the strong enrichment of 13C i

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Hurley, Sarah J., Boswell A. Wing, Claire E. Jasper, Nicholas C. Hill, and Jeffrey C. Cameron. "Carbon isotope evidence for the global physiology of Proterozoic cyanobacteria." Science Advances 7, no. 2 (2021): eabc8998. http://dx.doi.org/10.1126/sciadv.abc8998.

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Ancestral cyanobacteria are assumed to be prominent primary producers after the Great Oxidation Event [≈2.4 to 2.0 billion years (Ga) ago], but carbon isotope fractionation by extant marine cyanobacteria (α-cyanobacteria) is inconsistent with isotopic records of carbon fixation by primary producers in the mid-Proterozoic eon (1.8 to 1.0 Ga ago). To resolve this disagreement, we quantified carbon isotope fractionation by a wild-type planktic β-cyanobacterium (Synechococcus sp. PCC 7002), an engineered Proterozoic analog lacking a CO2-concentrating mechanism, and cyanobacterial mats. At mid-Prot

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Morasch, Barbara, Hans H. Richnow, Andrea Vieth, Bernhard Schink, and Rainer U. Meckenstock. "Stable Isotope Fractionation Caused by Glycyl Radical Enzymes during Bacterial Degradation of Aromatic Compounds." Applied and Environmental Microbiology 70, no. 5 (2004): 2935–40. http://dx.doi.org/10.1128/aem.70.5.2935-2940.2004.

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ABSTRACT Stable isotope fractionation was studied during the degradation of m-xylene, o-xylene, m-cresol, and p-cresol with two pure cultures of sulfate-reducing bacteria. Degradation of all four compounds is initiated by a fumarate addition reaction by a glycyl radical enzyme, analogous to the well-studied benzylsuccinate synthase reaction in toluene degradation. The extent of stable carbon isotope fractionation caused by these radical-type reactions was between enrichment factors (ε) of −1.5 and −3.9, which is in the same order of magnitude as data provided before for anaerobic toluene degra

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Кулешова, Т. Э., Е. С. Павлова та Н. Р. Галль. "Фракционирование изотопов углерода -=SUP=-13-=/SUP=-С/-=SUP=-12-=/SUP=-С из углекислого газа атмосферы в продукты фотосинтеза в листьях растений в зависимости от спектральных характеристик световой среды". Письма в журнал технической физики 46, № 16 (2020): 19. http://dx.doi.org/10.21883/pjtf.2020.16.49848.18333.

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We have studied influence of the light with various spectral characteristics, coming to plants during its growth, on the distribution of carbon isotopes between atmospheric carbon dioxide and the primary products of photosynthesis in plant leaves, using the developed set of methods and laboratory setups. The difference between the carbon isotopic composition in the air near the plants and in their leaves varies from 7 to 19 ‰, increase in the red component of the spectrum resulting in leave enrichment with light carbon isotope 12C. This difference reflects the degree of isotope fractionation d

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Miljević, Nada, and Dušan Golobočanin. "Potential Use of Environmental Isotopes in Pollutant Migration Studies." Archives of Industrial Hygiene and Toxicology 58, no. 2 (2007): 251–62. http://dx.doi.org/10.2478/v10004-007-0015-5.

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Potential Use of Environmental Isotopes in Pollutant Migration StudiesThis article presents the use of natural abundance stable isotope (hydrogen, carbon, nitrogen, oxygen, chlorine) analysis data as a tool for providing important information about the origin of contaminants, the contribution of different sources to a multi-source plume, characterisation of their complex transport (rate and mechanisms) and for evaluating the success of contaminated site remediation. Isotopic signatures of contaminants are useful tracers of their sources, while isotopic fractionation can be used to quantitative

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Keeffe, J. R., and A. J. Kresge. "Solvent and substrate isotope effects on the enolization and carbon-acid ionization of isobutyrophenone." Canadian Journal of Chemistry 74, no. 12 (1996): 2481–86. http://dx.doi.org/10.1139/v96-278.

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Bromine scavenging was used to measure rates of acid-catalyzed enolization of isobutyrophenone in H2O and in D2O solution and of isobutyrophenone-α-d in D2O solution. The results provide the solvent isotope effect kH +/kD + = 0.56 and the substrate isotope effect kH/kD = 6.2 on the enolization reaction, both of which are consistent with the generally accepted mechanism for this process. The present results in combination with literature information also provide the solvent isotope effect on the enolization equilibrium, KE(H2O)/KE(D2O) = 0.92, and the solvent isotope effect on the ionization of

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Kennedy, Brenda V., and H. Roy Krouse. "Isotope fractionation by plants and animals: implications for nutrition research." Canadian Journal of Physiology and Pharmacology 68, no. 7 (1990): 960–72. http://dx.doi.org/10.1139/y90-146.

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The isotopic compositions of animal tissues, minerals, and fluids reflect those of ingested food and water and inhaled gases. This relationship is illustrated by a review of data pertaining to five light elements of biological interest (carbon, nitrogen, hydrogen, oxygen, and sulphur). Processes affecting the isotopic composition of inorganic compounds in reservoirs are summarized, and isotope fractionation during transfer of elements from these inorganic reservoirs through progressive trophic levels of food webs is discussed. Variability of δ values within and among individuals, populations,

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Zhao, Rongsheng, Luquan Ren, Sunhua Deng, Youhong Sun, and Zhiyong Chang. "Constrain on Oil Recovery Stage during Oil Shale Subcritical Water Extraction Process Based on Carbon Isotope Fractionation Character." Energies 14, no. 23 (2021): 7839. http://dx.doi.org/10.3390/en14237839.

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In this work, Huadian oil shale was extracted by subcritical water at 365 °C with a time series (2–100 h) to better investigate the carbon isotope fractionation characteristics and how to use its fractionation characteristics to constrain the oil recovery stage during oil shale in situ exploitation. The results revealed that the maximum generation of oil is 70–100 h, and the secondary cracking is limited. The carbon isotopes of the hydrocarbon gases show a normal sequence, with no “rollover” and “reversals” phenomena, and the existence of alkene gases and the CH4-CO2-CO diagram implied that ne

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Sensuła, Barbara, та Anna Pazdur. "Influence of climate change on carbon and oxygen isotope fractionation factors between glucose and α-cellulose of pine wood". Geochronometria 40, № 2 (2013): 145–52. http://dx.doi.org/10.2478/s13386-013-0104-y.

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Abstract We present the first analysis of the influence of climate change on carbon and oxygen isotope fractionation factors for two saccharides (glucose and α-cellulose) of pine wood. The conifers grew in the Niepołomice Forest in Poland and the annual rings covered a time span from 1935 to 2000 AD. Glucose samples from acid hydrolysis of α-cellulose were extracted from annual tree rings. The carbon and oxygen isotope fractionation factors between glucose and α-cellulose were not stable over time. The mean value for the carbon isotope fractionation factors between glucose and α-cellulose was

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Colzi, L., O. Sipilä, E. Roueff, P. Caselli, and F. Fontani. "Carbon isotopic fractionation in molecular clouds." Astronomy & Astrophysics 640 (August 2020): A51. http://dx.doi.org/10.1051/0004-6361/202038251.

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Context. Carbon fractionation has been studied from a theoretical point of view with different models of time-dependent chemistry, including both isotope-selective photodissociation and low-temperature isotopic exchange reactions. Aims. Recent chemical models predict that isotopic exchange reactions may lead to a depletion of 13C in nitrile-bearing species, with 12C/13C ratios two times higher than the elemental abundance ratio of 68 in the local interstellar medium. Since the carbon isotopic ratio is commonly used to evaluate the 14N/15N ratios with the double-isotope method, it is important

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Jechalke, Sven, Mònica Rosell, Paula M. Martínez-Lavanchy, et al. "Linking Low-Level Stable Isotope Fractionation to Expression of the Cytochrome P450 Monooxygenase-EncodingethBGene for Elucidation of Methyltert-Butyl Ether Biodegradation in Aerated Treatment Pond Systems." Applied and Environmental Microbiology 77, no. 3 (2010): 1086–96. http://dx.doi.org/10.1128/aem.01698-10.

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ABSTRACTMultidimensional compound-specific stable isotope analysis (CSIA) was applied in combination with RNA-based molecular tools to characterize methyl tertiary (tert-) butyl ether (MTBE) degradation mechanisms occurring in biofilms in an aerated treatment pond used for remediation of MTBE-contaminated groundwater. The main pathway for MTBE oxidation was elucidated by linking the low-level stable isotope fractionation (mean carbon isotopic enrichment factor [εC] of −0.37‰ ± 0.05‰ and no significant hydrogen isotopic enrichment factor [εH]) observed in microcosm experiments to expression of

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Somsamak, Piyapawn, Hans H. Richnow, and Max M. Häggblom. "Carbon Isotope Fractionation during Anaerobic Degradation of Methyl tert-Butyl Ether under Sulfate-Reducing and Methanogenic Conditions." Applied and Environmental Microbiology 72, no. 2 (2006): 1157–63. http://dx.doi.org/10.1128/aem.72.2.1157-1163.2006.

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ABSTRACT Methyl tert-butyl ether (MTBE), an octane enhancer and a fuel oxygenate in reformulated gasoline, has received increasing public attention after it was detected as a major contaminant of water resources. Although several techniques have been developed to remediate MTBE-contaminated sites, the fate of MTBE is mainly dependent upon natural degradation processes. Compound-specific stable isotope analysis has been proposed as a tool to distinguish the loss of MTBE due to biodegradation from other physical processes. Although MTBE is highly recalcitrant, anaerobic degradation has been demo

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Zuiderweg, A., J. Kaiser, J. C. Laube, T. Röckmann, and R. Holzinger. "Stable carbon isotope fractionation in the UV photolysis of CFC-11 and CFC-12." Atmospheric Chemistry and Physics Discussions 11, no. 12 (2011): 33173–89. http://dx.doi.org/10.5194/acpd-11-33173-2011.

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Abstract. The chlorofluorocarbons CFC-11 (CCl3F) and CFC-12 (CCl2F2) are stable atmospheric compounds that are produced at the earth's surface, but removed only at high altitudes in the stratosphere, where their removal liberates atomic chlorine that then catalytically destroys stratospheric ozone. For such long-lived compounds, isotope effects in the stratospheric removal reactions have a large effect on their global isotope budgets. We have determined the photolytic isotope fractionation for stable carbon isotopes of CFC-11 and CFC-12 in laboratory experiments. 13C/12C isotope fractionations

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Zuiderweg, A., J. Kaiser, J. C. Laube, T. Röckmann, and R. Holzinger. "Stable carbon isotope fractionation in the UV photolysis of CFC-11 and CFC-12." Atmospheric Chemistry and Physics 12, no. 10 (2012): 4379–85. http://dx.doi.org/10.5194/acp-12-4379-2012.

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Abstract. The chlorofluorocarbons CFC-11 (CFCl3) and CFC-12 (CF2Cl2) are stable atmospheric compounds that are produced at the earth's surface, but removed only at high altitudes in the stratosphere by photolytic reactions. Their removal liberates atomic chlorine that then catalytically destroys stratospheric ozone. For such long-lived compounds, isotope effects in the stratospheric removal reactions have a large effect on their global isotope budgets. We have demonstrated a photolytic isotope fractionation for stable carbon isotopes of CFC-11 and CFC-12 in laboratory experiments using broadba

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Gao, Cuiping, Yunlong Wang, Yu Xia, et al. "Stable Carbon Isotope Analysis of Hexachlorocyclohexanes by Liquid–Liquid Extraction Gas Chromatography Isotope Ratio Mass Spectrometry: Method Evaluation and Applications." Molecules 27, no. 9 (2022): 2874. http://dx.doi.org/10.3390/molecules27092874.

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Compound specific isotope analysis (CSIA) and enantiomer specific isotope analysis (ESIA) are powerful tools for assessing the fate of hexachlorocyclohexanes (HCHs) in the environment. However, there is no systematic study on the CSIA and ESIA analysis test methods of the carbon isotopes of HCHs in water and soil environments, in particular the isotope fractionation in the pre-concentration process. We endeavored to test the compatibility of CSIA and ESIA with the liquid–liquid extraction method of HCHs in water. The results showed that there were negligible changes in the δ13C of HCHs after e

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Nijenhuis, Ivonne, Janet Andert, Kirsten Beck, Matthias Kästner, Gabriele Diekert, and Hans-Hermann Richnow. "Stable Isotope Fractionation of Tetrachloroethene during Reductive Dechlorination by Sulfurospirillum multivorans and Desulfitobacterium sp. Strain PCE-S and Abiotic Reactions with Cyanocobalamin." Applied and Environmental Microbiology 71, no. 7 (2005): 3413–19. http://dx.doi.org/10.1128/aem.71.7.3413-3419.2005.

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ABSTRACT Carbon stable isotope fractionation of tetrachloroethene (PCE) during reductive dechlorination by whole cells and crude extracts of Sulfurospirillum multivorans and Desulfitobacterium sp. strain PCE-S and the abiotic reaction with cyanocobalamin (vitamin B12) was studied. Fractionation was largest during the reaction with cyanocobalamin with αC = 1.0132. Stable isotope fractionation was lower but still in a similar order of magnitude for Desulfitobacterium sp. PCE-S (αC = 1.0052 to 1.0098). The isotope fractionation of PCE during dehalogenation by S. multivorans was lower by 1 order o

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Zhen, Shucong, and Wei Zhu. "Determination of the in situ growth rate of Microcystis based on carbon and nitrogen stable isotope fractionation." Water Supply 18, no. 3 (2017): 984–93. http://dx.doi.org/10.2166/ws.2017.172.

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Abstract Stable isotope fractionation of carbon and nitrogen in algal cells can be affected by photosynthesis, temperature, nutrient and CO2 concentrations, and cell size. As a consequence, carbon and nitrogen stable isotope techniques are not popular for determining algal growth rates. To counter these issues, this study used BG11 medium to cultivate Microcystis in the laboratory. First, the carbon and nitrogen stable isotope values of the culture medium and the algae are determined. Then, based on changes in isotope fractionation before and after cell division, a function μ = 1.32(1 + x)−0.5

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Wang, Chong Jing, He Zhang, Jian Ming Chen, and Wen Bin Chen. "Organic Carbon & Nitrogen Stable Isotope Geochemistry of Anthraxolite from Different Fractures in Xiangxi, China." Applied Mechanics and Materials 733 (February 2015): 136–39. http://dx.doi.org/10.4028/www.scientific.net/amm.733.136.

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In order to analyze the stable organic carbon isotope characteristics and the causes of anthrax lite, 14 samples, containing hydrocarbon source rock, rock and anthrax lite, were selected to test the stable organic carbon and organic nitrogen isotope. Results showed that the relations of stable organic carbon isotope between source rock and anthrax lite were that δ13C source rock <δ13Csmall fault<δ13Clarge fault. Maybe the Early Cambrian anoxic events leaded the hydrocarbon source rock δ13C value low, and different metallogenic evolution and the isotopic fractionation process may be the c

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Epov, Vladimir N. "Mechanisms of Oxidation-Reduction Reactions Can Be Predicted by the Magnetic Isotope Effect." Advances in Physical Chemistry 2011 (December 20, 2011): 1–7. http://dx.doi.org/10.1155/2011/450325.

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Magnetic isotope effect can cause mass-independent isotope fractionation, which can be used to predict the mechanisms of chemical reactions. In this critical paper, the isotope fractionation caused by magnetic isotope effect is used to understand detailed mechanisms of oxidation-reduction reactions for some previously published experimental data. Due to the rule that reactions are allowed for certain electron spin state, and forbidden for others, magnetic isotopes show chemical anomalies during these reactions due to the hyperfine interaction of the nuclear spin with the electron spin. It is d

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Mancini, Silvia A., Ania C. Ulrich, Georges Lacrampe-Couloume, Brent Sleep, Elizabeth A. Edwards, and Barbara Sherwood Lollar. "Carbon and Hydrogen Isotopic Fractionation during Anaerobic Biodegradation of Benzene." Applied and Environmental Microbiology 69, no. 1 (2003): 191–98. http://dx.doi.org/10.1128/aem.69.1.191-198.2003.

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ABSTRACT Compound-specific isotope analysis has the potential to distinguish physical from biological attenuation processes in the subsurface. In this study, carbon and hydrogen isotopic fractionation effects during biodegradation of benzene under anaerobic conditions with different terminal-electron-accepting processes are reported for the first time. Different enrichment factors (ε) for carbon (range of −1.9 to −3.6‰) and hydrogen (range of −29 to −79‰) fractionation were observed during biodegradation of benzene under nitrate-reducing, sulfate-reducing, and methanogenic conditions. These di

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van der Meer, Marcel T. J., Stefan Schouten, Jaap S. Sinninghe Damsté, Jan W. de Leeuw, and David M. Ward. "Compound-Specific Isotopic Fractionation Patterns Suggest Different Carbon Metabolisms among Chloroflexus-Like Bacteria in Hot-Spring Microbial Mats." Applied and Environmental Microbiology 69, no. 10 (2003): 6000–6006. http://dx.doi.org/10.1128/aem.69.10.6000-6006.2003.

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ABSTRACT Stable carbon isotope fractionations between dissolved inorganic carbon and lipid biomarkers suggest photoautotrophy by Chloroflexus-like organisms in sulfidic and nonsulfidic Yellowstone hot springs. Where co-occurring, cyanobacteria appear to cross-feed Chloroflexus-like organisms supporting photoheterotrophy as well, although the relatively small 13C fractionation associated with cyanobacterial sugar biosynthesis may sometimes obscure this process.

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Londry, Kathleen L., and David J. Des Marais. "Stable Carbon Isotope Fractionation by Sulfate-Reducing Bacteria." Applied and Environmental Microbiology 69, no. 5 (2003): 2942–49. http://dx.doi.org/10.1128/aem.69.5.2942-2949.2003.

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ABSTRACT Biogeochemical transformations occurring in the anoxic zones of stratified sedimentary microbial communities can profoundly influence the isotopic and organic signatures preserved in the fossil record. Accordingly, we have determined carbon isotope discrimination that is associated with both heterotrophic and lithotrophic growth of pure cultures of sulfate-reducing bacteria (SRB). For heterotrophic-growth experiments, substrate consumption was monitored to completion. Sealed vessels containing SRB cultures were harvested at different time intervals, and δ13C values were determined for

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Gessler, Arthur, Claudia Keitel, Naomi Kodama та ін. "δ13C of organic matter transported from the leaves to the roots in Eucalyptus delegatensis: short-term variations and relation to respired CO2". Functional Plant Biology 34, № 8 (2007): 692. http://dx.doi.org/10.1071/fp07064.

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Post-photosynthetic carbon isotope fractionation might alter the isotopic signal imprinted on organic matter (OM) during primary carbon fixation by Rubisco. To characterise the influence of post-photosynthetic processes, we investigated the effect of starch storage and remobilisation on the stable carbon isotope signature (δ13C) of different carbon pools in the Eucalyptus delegatensis R. T. Baker leaf and the potential carbon isotope fractionation associated with phloem transport and respiration. Twig phloem exudate and leaf water-soluble OM showed diel variations in δ13C of up to 2.5 and 2‰,

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Sim, Min Sub, Shuhei Ono, and Tanja Bosak. "Effects of Iron and Nitrogen Limitation on Sulfur Isotope Fractionation during Microbial Sulfate Reduction." Applied and Environmental Microbiology 78, no. 23 (2012): 8368–76. http://dx.doi.org/10.1128/aem.01842-12.

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ABSTRACTSulfate-reducing microbes utilize sulfate as an electron acceptor and produce sulfide that is depleted in heavy isotopes of sulfur relative to sulfate. Thus, the distribution of sulfur isotopes in sediments can trace microbial sulfate reduction (MSR), and it also has the potential to reflect the physiology of sulfate-reducing microbes. This study investigates the relationship between the availability of iron and reduced nitrogen and the magnitude of S-isotope fractionation during MSR by a marine sulfate-reducing bacterium, DMSS-1, aDesulfovibriospecies, isolated from salt marsh in Cape

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Könneke, Martin, Julius S. Lipp, and Kai-Uwe Hinrichs. "Carbon isotope fractionation by the marine ammonia-oxidizing archaeon Nitrosopumilus maritimus." Organic Geochemistry 48 (May 3, 2012): 21–24. https://doi.org/10.1016/j.orggeochem.2012.04.007.

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Abstract Ammonia-oxidizing archaea (AOA) are abundant and widely distributed microorganisms in aquatic and terrestrial habitats. By catalyzing the first and rate limiting step in nitrification, these chemolithoautotrophs play a significant role in the global nitrogen cycle and contribute to primary production. Here, the carbon isotopic fractionation relative to inorganic carbon source was determined for bulk biomass, biphytanes and polar lipid bound sugars of a marine AOA pure culture. Bulk biomass and biphytanes from <em>Nitrosopumilus maritimus</em> showed identical carbon isotope fractionat

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Thompson, Peter A., and Stephen E. Calvert. "Carbon isotope fractionation by Emiliania huxleyi." Limnology and Oceanography 40, no. 4 (1995): 673–79. http://dx.doi.org/10.4319/lo.1995.40.4.0673.

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Woods, Paul M., and Karen Willacy. "CARBON ISOTOPE FRACTIONATION IN PROTOPLANETARY DISKS." Astrophysical Journal 693, no. 2 (2009): 1360–78. http://dx.doi.org/10.1088/0004-637x/693/2/1360.

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Musat, Florin, Carsten Vogt, and Hans H. Richnow. "Carbon and Hydrogen Stable Isotope Fractionation Associated with the Aerobic and Anaerobic Degradation of Saturated and Alkylated Aromatic Hydrocarbons." Journal of Molecular Microbiology and Biotechnology 26, no. 1-3 (2016): 211–26. http://dx.doi.org/10.1159/000442161.

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Saturated hydrocarbons (alkanes) and alkylated aromatic hydrocarbons are abundant environmental compounds. Hydrocarbons are primarily removed from the environment by biodegradation, a process usually associated with moderate carbon and significant hydrogen isotope fractionation allowing monitoring of biodegradation processes in the environment. Here, we review the carbon and hydrogen stable isotope fractionation associated with the cleavage of C-H bonds at alkyl chains of hydrocarbons. Propane, <i>n</i>-butane and ethylbenzene were used as model components for alkyl moieties of ali

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Balcaen, A., E. Claeys, V. Fievez, P. Boeckx, O. van Cleemput, and S. de Smet. "Stable carbon isotope analysis of faecal and blood samples of sheep in relation to the diet." Proceedings of the British Society of Animal Science 2003 (2003): 159. http://dx.doi.org/10.1017/s1752756200013181.

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Stable isotopes have been extraordinarily helpful in understanding animal migration, diet, food webs and nutrient flow (Hilderbrand et al., 1996), based on the property that C3 and C4 plants possess distinctly different 13C/12C ratios (δ13C value) due to isotopic fractionation during photosynthetic carbon fixation (Smith & Epstein, 1971). Most woody species and temperate graminoids assimilate carbon via the Calvin cycle (C3), which discriminates stronger against the heavier isotope (13C) than Hatch-Slack (C4) species (tropical and subtropical graminoids and some shrubs). C3 and C4 plant sp

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Polyakov, V. B., M. V. Mironenko, and M. V. Alenina. "Simultaneous Calculation of Chemical and Isotope Equilibria Using the GEOCHEQ_Isotope Software: Oxygen Isotopes." Geochemistry International 59, no. 11 (2021): 1090–105. http://dx.doi.org/10.1134/s0016702921110094.

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Abstract— The GEOCHEQ_Isotope software package, elaborated previously for modeling chemical and carbon isotope equilibria in hydrothermal and hydrogeochemical systems by minimizing the Gibbs energy, is extended to the simultaneous calculation of carbon and oxygen isotopic effects. Similar to what was done for carbon, the β-factor formalism was used to develop algorithms and a database for calculating the isotopic effects of oxygen. According to the developed algorithm, the Gibbs energy of formation of a rare isotopologue, G*(P, T), is calculated through the Gibbs energy of formation of the mai

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Penger, Jörn, Ralf Conrad, and Martin Blaser. "Stable Carbon Isotope Fractionation by Methylotrophic Methanogenic Archaea." Applied and Environmental Microbiology 78, no. 21 (2012): 7596–602. http://dx.doi.org/10.1128/aem.01773-12.

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ABSTRACTIn natural environments methane is usually produced by aceticlastic and hydrogenotrophic methanogenic archaea. However, some methanogens can use C1compounds such as methanol as the substrate. To determine the contributions of individual substrates to methane production, the stable-isotope values of the substrates and the released methane are often used. Additional information can be obtained by using selective inhibitors (e.g., methyl fluoride, a selective inhibitor of acetoclastic methanogenesis). We studied stable carbon isotope fractionation during the conversion of methanol to meth

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Macario, Kita D., Fabiana M. Oliveira, Vinicius N. Moreira, et al. "Optimization of the Amount of Zinc in the Graphitization Reaction for Radiocarbon AMS Measurements at LAC-UFF." Radiocarbon 59, no. 3 (2016): 885–91. http://dx.doi.org/10.1017/rdc.2016.42.

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AbstractThe Radiocarbon Laboratory of the Universidade Federal Fluminense, in Brazil, has been successfully applying the zinc reduction method for graphitization of carbon samples since the development of its early protocols in 2009. Successive methodological research aiming to improve and, ultimately, optimize the precision and accuracy of our results indicates that graphitization temperatures as low as 460°C promote erratic 13C isotopic fractionation, but an approximately constant fractionation of about –5‰ is achieved at 520°C. In this work, we present isotope ratio mass spectrometry (IRMS)

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Tcherkez, Guillaume. "Viewpoint: How large is the carbon isotope fractionation of the photorespiratory enzyme glycine decarboxylase?" Functional Plant Biology 33, no. 10 (2006): 911. http://dx.doi.org/10.1071/fp06098.

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Despite the intense effort developed over the past 10 years to determine the 12C / 13C isotope fractionation associated with photorespiration, much uncertainty remains about the amplitude, and even the sign, of the 12C / 13C isotope fractionation of glycine decarboxylase, the enzyme that produces CO2 during the photorespiratory cycle. In fact, leaf gas-exchange data have repeatedly indicated that CO2 evolved by photorespiration is depleted in 13C compared with the source material, while glycine decarboxylase has mostly favoured 13C in vitro. Here I give theoretical insights on the glycine deca

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Chen, Xin, Weishu Zhao, Liang Dong, et al. "Impact of metabolism and temperature on ²H ∕ ¹H fractionation in lipids of the marine bacterium Shewanella piezotolerans WP3." Biogeosciences 20, no. 7 (2023): 1491–504. http://dx.doi.org/10.5194/bg-20-1491-2023.

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Abstract. Compound-specific hydrogen isotopes have increasingly been used as a powerful proxy for investigating biogeochemical cycles and climate change over the past 2 decades. Understanding the hydrogen isotope in extant organisms is fundamental for us to interpret such isotope signals preserved in natural environmental samples. Here, we studied the controls on hydrogen isotope fractionation between fatty acids and growth water by an Fe-reducing heterotrophic marine bacterium Shewanella piezotolerans WP3 growing on different organic substrates, including N-acetyl-D-glucosamine (GlcNac), gluc

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Carpenter, Chris. "Chemical and Carbon Isotope Composition Proves Effective as Gas Diagnostic Tool." Journal of Petroleum Technology 75, no. 09 (2023): 94–96. http://dx.doi.org/10.2118/0923-0094-jpt.

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_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 209992, “Gas Chemical and Carbon Isotope Composition as a Diagnostic Tool for Energy,” by Zainab Almubarak, SPE, Mohammad Alrowaie, and Feng Lu, Saudi Aramco, et al. The paper has not been peer reviewed. _ Chemical and carbon isotopic compositions of produced gases are useful tools to monitor gas production and to assess their origin, thermal maturity, and migration. In the complete paper, the authors present different geochemical approaches to assess the origin of gases and thermal maturity and

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Hüls, C. M., H. Erlenkeuser, M.-J. Nadeau, P. M. Grootes, and N. Andersen. "Experimental Study on the Origin of Cremated Bone Apatite Carbon." Radiocarbon 52, no. 2 (2010): 587–99. http://dx.doi.org/10.1017/s0033822200045628.

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Bones that have undergone burning at high temperatures (i.e. cremation) no longer contain organic carbon. Lanting et al. (2001) proposed that some of the original structural carbonate, formed during bioapatite formation, survives. This view is based on paired radiocarbon dating of cremated bone apatite and contemporary charcoal. However, stable carbon isotope composition of carbonate in cremated bones is consistently light compared to the untreated material and is closer to the δ13C values seen in C3 plant material. This raises the question of the origin of carbonate carbon in cremated bone ap

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