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Lenard T. Metabolic activity of deep living cyanobacteria: Photosynthesis versus respiration. JOURNAL OF PHYCOLOGY 2024; 60:639-641. [PMID: 38858854 DOI: 10.1111/jpy.13458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2024]
Affiliation(s)
- Tomasz Lenard
- Department of Animal Physiology and Toxicology, Faculty of Medicine, The John Paul II Catholic University of Lublin, Lublin, Poland
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Dordoni M, Tittel J, Rosenlöcher Y, Rinke K, Barth JAC. Metabolic activity of Planktothrix rubescens and its consequences on oxygen dynamics in laboratory experiment: A stable isotope study. JOURNAL OF PHYCOLOGY 2024; 60:642-653. [PMID: 38634250 DOI: 10.1111/jpy.13455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 01/21/2024] [Accepted: 03/08/2024] [Indexed: 04/19/2024]
Abstract
Fluctuations in dissolved oxygen (DO) contents in natural waters can become intense during cyanobacteria blooms. In a reconnaissance study, we investigated DO concentrations and stable isotope dynamics during a laboratory experiment with the cyanobacterium Planktothrix rubescens in order to obtain insights into primary production under specific conditions. This observation was extended to sub-daily timescales with alternating light and dark phases. Dissolved oxygen concentrations and its isotopes (δ18ODO) ranged from 0.02 to 0.06 mmol · L-1 and from +9.6‰ to +23.4‰. The δ18ODO proved to be more sensitive than concentration measurements in response to metabolic variation and registered earlier shifts to dominance by respiration. Oxygen (O2) contents in the headspace and its isotopes (δ18OO2) ranged from 2.62 to 3.20 mmol · L-1 and from +9.8‰ to +21.9‰. Headspace samples showed less fluctuations in concentration and isotope trends because aquatic processes were hardly able to alter signals once the gas had reached the headspace. Headspace δ18OO2 values were corrected for gas-water equilibration and were determined to be higher than the mean δ18OH2O of -8.7‰. This finding suggests that counteracting respiration was important even during the highest photosynthetic activity. Additionally, headspace analyses led to the definition of a fractionation factor for respiration (αR) of this cyanobacterium with a value of 0.980. This value confirms the one commonly used for cyanobacteria. Our findings may become important for the management of water bodies where decreases in DO are caused by cyanobacteria.
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Affiliation(s)
- Marlene Dordoni
- Department of Geography and Geosciences, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Jörg Tittel
- Helmholtz Centre for Environmental Research-UFZ, Magdeburg, Germany
| | | | - Karsten Rinke
- Helmholtz Centre for Environmental Research-UFZ, Magdeburg, Germany
| | - Johannes A C Barth
- Department of Geography and Geosciences, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
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Piatka DR, Venkiteswaran JJ, Uniyal B, Kaule R, Gilfedder B, Barth JAC. Dissolved oxygen isotope modelling refines metabolic state estimates of stream ecosystems with different land use background. Sci Rep 2022; 12:10204. [PMID: 35715436 PMCID: PMC9205993 DOI: 10.1038/s41598-022-13219-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 05/18/2022] [Indexed: 11/12/2022] Open
Abstract
Dissolved oxygen (DO) is crucial for aerobic life in streams and rivers and mostly depends on photosynthesis (P), ecosystem respiration (R) and atmospheric gas exchange (G). However, climate and land use changes progressively disrupt metabolic balances in natural streams as sensitive reflectors of their catchments. Comprehensive methods for mapping fundamental ecosystem services become increasingly important in a rapidly changing environment. In this work we tested DO and its stable isotope (18O/16O) ratios as novel tools for the status of stream ecosystems. For this purpose, six diel sampling campaigns were performed at three low-order and mid-latitude European streams with different land use patterns. Modelling of diel DO and its stable isotopes combined with land use analyses showed lowest P rates at forested sites, with a minimum of 17.9 mg m−2 h−1. Due to high R rates between 230 and 341 mg m−2 h−1 five out of six study sites showed a general heterotrophic state with P:R:G ratios between 0.1:1.1:1 and 1:1.9:1. Only one site with agricultural and urban influences showed a high P rate of 417 mg m−2 h−1 with a P:R:G ratio of 1.9:1.5:1. Between all sites gross G rates varied between 148 and 298 mg m−2 h−1. In general, metabolic rates depend on the distance of sampling locations to river sources, light availability, nutrient concentrations and possible exchanges with groundwater. The presented modelling approach introduces a new and powerful tool to study effects of land use on stream health. Such approaches should be integrated into future ecological monitoring.
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Affiliation(s)
- David R Piatka
- Department of Geography and Geosciences, GeoZentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schlossgarten 5, 91054, Erlangen, Germany. .,Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research (IMK-IFU), Kreuzeckbahnstr. 19, 82467, Garmisch-Partenkirchen, Germany.
| | - Jason J Venkiteswaran
- Department of Geography and Environmental Studies, Wilfrid Laurier University, 75 University Avenue West, Waterloo, ON, N2L 3C5, Canada
| | - Bhumika Uniyal
- Professorship of Ecological Services, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Universitaetsstr. 30, 95447, Bayreuth, Germany
| | - Robin Kaule
- Limnological Research Station, BayCEER, Department of Hydrology, University of Bayreuth, 95440, Bayreuth, Germany
| | - Benjamin Gilfedder
- Limnological Research Station, BayCEER, Department of Hydrology, University of Bayreuth, 95440, Bayreuth, Germany
| | - Johannes A C Barth
- Department of Geography and Geosciences, GeoZentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schlossgarten 5, 91054, Erlangen, Germany
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Köhler I, Piatka D, Barth JAC, Martinez RE. Beware of effects on isotopes of dissolved oxygen during storage of natural iron-rich water samples: A technical note. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e9024. [PMID: 33305417 DOI: 10.1002/rcm.9024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/21/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
RATIONALE Investigations of the isotope ratios of dissolved oxygen (δ18 ODO ) provide valuable information about the oxygen cycle in aquatic systems. However, oxidation of Fe(II) may change pristine δ18 ODO values during storage and can lead to a misinterpretation. We sampled an Fe(II)-rich spring system and measured δ18 ODO values at various time intervals in order to determine influences of Fe-oxidation. METHODS Water samples were collected from an Fe-rich spring and related stream and the δ18 ODO values were measured in fresh, 4- and 13-day-old samples with an isotope ratio mass spectrometer. Three replicates were measured for each sample with a 1σ of ± 0.2‰. On-site parameters and Fe(II) contents were also measured over the course of the spring system by multi-parameter probes and spectrophotometry. RESULTS The δ18 ODO values over the course of the spring system in fresh, 4- and 13-day-old samples revealed differences of up to 8‰. We explain this increase by the consumption of DO by Fe(II)-oxidation. After a flow length of 85 m the differences in δ18 ODO values between fresh and older samples decreased because most of the Fe(II) was consumed. CONCLUSIONS False interpretations of δ18 ODO values are possible if Fe-rich water samples are measured after too long storage, and we recommend measurement immediately after sampling.
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Affiliation(s)
- Inga Köhler
- Department of Geography and Geosciences, GeoZentrum Nordbayern, Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Schlossgarten 5, Erlangen, 91054, Germany
| | - David Piatka
- Department of Geography and Geosciences, GeoZentrum Nordbayern, Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Schlossgarten 5, Erlangen, 91054, Germany
| | - Johannes A C Barth
- Department of Geography and Geosciences, GeoZentrum Nordbayern, Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Schlossgarten 5, Erlangen, 91054, Germany
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Haschke S, Mader M, Schlicht S, Roberts AM, Angeles-Boza AM, Barth JAC, Bachmann J. Direct oxygen isotope effect identifies the rate-determining step of electrocatalytic OER at an oxidic surface. Nat Commun 2018; 9:4565. [PMID: 30385759 PMCID: PMC6212532 DOI: 10.1038/s41467-018-07031-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 10/09/2018] [Indexed: 11/22/2022] Open
Abstract
Understanding the mechanism of water oxidation to dioxygen represents the bottleneck towards the design of efficient energy storage schemes based on water splitting. The investigation of kinetic isotope effects has long been established for mechanistic studies of various such reactions. However, so far natural isotope abundance determination of O2 produced at solid electrode surfaces has not been applied. Here, we demonstrate that such measurements are possible. Moreover, they are experimentally simple and sufficiently accurate to observe significant effects. Our measured kinetic isotope effects depend strongly on the electrode material and on the applied electrode potential. They suggest that in the case of iron oxide as the electrode material, the oxygen evolution reaction occurs via a rate-determining O−O bond formation via nucleophilic water attack on a ferryl unit. Understanding reaction mechanisms is crucial for catalyst design. Here, natural-abundance isotope quantifications of O2 yield mechanistically significant reaction kinetic isotope effects for water oxidation over metal oxide electrodes, the bottleneck step of water electrolysis.
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Affiliation(s)
- Sandra Haschke
- Department of Chemistry and Pharmacy, Chemistry of Thin Film Materials, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstr. 4, 91058, Erlangen, Germany
| | - Michael Mader
- Department für Geographie und Geowissenschaften, GeoZentrum NordBayern, Applied Geology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schlossgarten 5, 91054, Erlangen, Germany
| | - Stefanie Schlicht
- Department of Chemistry and Pharmacy, Chemistry of Thin Film Materials, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstr. 4, 91058, Erlangen, Germany
| | - André M Roberts
- Department für Geographie und Geowissenschaften, GeoZentrum NordBayern, Applied Geology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schlossgarten 5, 91054, Erlangen, Germany
| | - Alfredo M Angeles-Boza
- Department of Chemistry and Institute of Materials Science, University of Connecticut, 55 North Eagleville Rd., Storrs, CT, 06269, USA.
| | - Johannes A C Barth
- Department für Geographie und Geowissenschaften, GeoZentrum NordBayern, Applied Geology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schlossgarten 5, 91054, Erlangen, Germany.
| | - Julien Bachmann
- Department of Chemistry and Pharmacy, Chemistry of Thin Film Materials, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstr. 4, 91058, Erlangen, Germany. .,Institute of Chemistry, Saint Petersburg State University, Universitetskii pr. 26, Saint Petersburg, Russian Federation, 198504.
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