Articles | Volume 17, issue 3
https://doi.org/10.5194/bg-17-649-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-17-649-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
07 Feb 2020
Research article |
| 07 Feb 2020
| 07 Feb 2020
Sterol preservation in hypersaline microbial mats
Yan Shen
CORRESPONDING AUTHOR
Department of Geobiology, Geoscience Centre,
Georg-August-Universität Göttingen, Göttingen, Germany
Volker Thiel
Department of Geobiology, Geoscience Centre,
Georg-August-Universität Göttingen, Göttingen, Germany
Pablo Suarez-Gonzalez
Área de Geología, Universidad Rey Juan Carlos, Madrid, Spain
Sebastiaan W. Rampen
Department of Geobiology, Geoscience Centre,
Georg-August-Universität Göttingen, Göttingen, Germany
Joachim Reitner
Department of Geobiology, Geoscience Centre,
Georg-August-Universität Göttingen, Göttingen, Germany
“Origin of Life” working group, Göttingen Academy of Sciences and
Humanities, Göttingen, Germany
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Wanli Xiang, Jan-Peter Duda, Andreas Pack, Mark van Zuilen, and Joachim Reitner
EGUsphere, https://doi.org/10.5194/egusphere-2024-1007, https://doi.org/10.5194/egusphere-2024-1007, 2024
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We investigated the formation of early Archean (~3.5–3.4 Ga) carbonates in the Pilbara Craton, Western Australia, demonstrating the presence of an oceanic crust-, an organo-carbonate-, and a microbial carbonate factory. Notably, (a)biotic organic matter as well as hydrothermal fluids were centrally involved in carbonate precipitation. Since carbonates are widespread in the Archean, they may have constituted major carbon sinks that modulated early Earth’s carbon cycle and, hence, climate system.
Manuel Reinhardt, Walter Goetz, Jan-Peter Duda, Christine Heim, Joachim Reitner, and Volker Thiel
Biogeosciences, 16, 2443–2465, https://doi.org/10.5194/bg-16-2443-2019, https://doi.org/10.5194/bg-16-2443-2019, 2019
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Organic matter in Archean hydrothermal cherts may contain molecular traces of early life. Alteration processes during and after deposition, however, may have obliterated potential biosignatures. Our results from modern analog samples (Pleistocene cherts from Lake Magadi, Kenya) show that biomolecules can survive early hydrothermal destruction in the macromolecular fraction of the organic matter. A conservation of molecular biosignatures in Archean hydrothermal cherts therefore seems possible.
Blanca Rincón-Tomás, Jan-Peter Duda, Luis Somoza, Francisco Javier González, Dominik Schneider, Teresa Medialdea, Esther Santofimia, Enrique López-Pamo, Pedro Madureira, Michael Hoppert, and Joachim Reitner
Biogeosciences, 16, 1607–1627, https://doi.org/10.5194/bg-16-1607-2019, https://doi.org/10.5194/bg-16-1607-2019, 2019
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Cold-water corals were found at active sites in Pompeia Province (Gulf of Cádiz). Since seeped fluids are harmful for the corals, we approached the environmental conditions that allow corals to colonize carbonates while seepage occurs. As a result, we propose that chemosynthetic microorganisms (i.e. sulfide-oxidizing bacteria and AOM-related microorganisms) play an important role in the colonization of the corals at these sites by feeding on the seeped fluids and avoiding coral damage.
Beate Stawiarski, Stefan Otto, Volker Thiel, Ulf Gräwe, Natalie Loick-Wilde, Anna K. Wittenborn, Stefan Schloemer, Janine Wäge, Gregor Rehder, Matthias Labrenz, Norbert Wasmund, and Oliver Schmale
Biogeosciences, 16, 1–16, https://doi.org/10.5194/bg-16-1-2019, https://doi.org/10.5194/bg-16-1-2019, 2019
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The understanding of surface water methane production in the world oceans is still poor. By combining field studies and incubation experiments, our investigations suggest that zooplankton contributes to subthermocline methane enrichments in the central Baltic Sea by methane production within the digestive tract of copepods and/or by methane production through release of methane precursor substances into the surrounding water, followed by microbial degradation to methane.
Sergio Balzano, Julie Lattaud, Laura Villanueva, Sebastiaan W. Rampen, Corina P. D. Brussaard, Judith van Bleijswijk, Nicole Bale, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 15, 5951–5968, https://doi.org/10.5194/bg-15-5951-2018, https://doi.org/10.5194/bg-15-5951-2018, 2018
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We tried to identify the microbes which biosynthesize a class of lipids widespread in seawater, the long chain alkyl diols (LCDs). We could not find any microorganism likely involved in the production of LCDs. The amounts of LCDs found are too high to be produced by living organisms and are likely to be part of the refractory organic matter persisting for long periods in the water column.
Sonja Geilert, Christian Hensen, Mark Schmidt, Volker Liebetrau, Florian Scholz, Mechthild Doll, Longhui Deng, Annika Fiskal, Mark A. Lever, Chih-Chieh Su, Stefan Schloemer, Sudipta Sarkar, Volker Thiel, and Christian Berndt
Biogeosciences, 15, 5715–5731, https://doi.org/10.5194/bg-15-5715-2018, https://doi.org/10.5194/bg-15-5715-2018, 2018
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Abrupt climate changes in Earth’s history might have been triggered by magmatic intrusions into organic-rich sediments, which can potentially release large amounts of greenhouse gases. In the Guaymas Basin, vigorous hydrothermal venting at the ridge axis and off-axis inactive vents show that magmatic intrusions are an effective way to release carbon but must be considered as very short-lived processes in a geological sense. These results need to be taken into account in future climate models.
Alexander R. Schmidt, Dennis Grabow, Christina Beimforde, Vincent Perrichot, Jouko Rikkinen, Simona Saint Martin, Volker Thiel, and Leyla J. Seyfullah
Foss. Rec., 21, 213–221, https://doi.org/10.5194/fr-21-213-2018, https://doi.org/10.5194/fr-21-213-2018, 2018
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Amber is fossilized resin and so has a terrestrial source; however, very rarely have marine microorganisms been reported, and only in a few amber pieces. We aim to understand how this rare phenomenon could be possible. Several different mechanisms were proposed, and we then tested the wind-blown idea via our experiments on resin-rich forests on the coast of New Caledonia. These forests encompass the best model for the Cretaceous ambers that contain these marine microorganisms.
Jan-Peter Duda, Volker Thiel, Thorsten Bauersachs, Helge Mißbach, Manuel Reinhardt, Nadine Schäfer, Martin J. Van Kranendonk, and Joachim Reitner
Biogeosciences, 15, 1535–1548, https://doi.org/10.5194/bg-15-1535-2018, https://doi.org/10.5194/bg-15-1535-2018, 2018
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The origin of organic matter in the oldest rocks on Earth is commonly ambiguous (biotic vs. abiotic). This problem culminates in the case of hydrothermal chert veins that contain abundant organic matter. Here we demonstrate a microbial origin of kerogen embedded in a 3.5 Gyr old hydrothermal chert vein. We explain this finding with the large-scale redistribution of biomass by hydrothermal fluids, emphasizing the interplay between biological and abiological processes on the early Earth.
M. Rodrigo-Gámiz, S. W. Rampen, H. de Haas, M. Baas, S. Schouten, and J. S. Sinninghe Damsté
Biogeosciences, 12, 6573–6590, https://doi.org/10.5194/bg-12-6573-2015, https://doi.org/10.5194/bg-12-6573-2015, 2015
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This research reports a test of the applicability of three organic-derived temperature proxies (UK'37, TEX86 and LDI) at high latitudes around Iceland. A range of samples including suspended particular material (SPM), trapped descending particles and surface sediments were collected to test the different proxies in the water column and the sediment.The combination of three independent SST organic proxies provided important information about seasonality and differences in habitat depth.
C. Berndmeyer, V. Thiel, O. Schmale, N. Wasmund, and M. Blumenberg
Biogeosciences, 11, 7009–7023, https://doi.org/10.5194/bg-11-7009-2014, https://doi.org/10.5194/bg-11-7009-2014, 2014
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The water column of the Landsort Deep, central Baltic Sea, is stratified into an oxic, suboxic, and anoxic zone. This stratification controls the distributions of individual microbial communities and biogeochemical processes. Our study of in situ biomarkers in the Landsort Deep provides an integrated insight into the distribution of relevant compounds and describes useful tracers to reconstruct stratified water columns in the geological record.
M. Blumenberg, C. Berndmeyer, M. Moros, M. Muschalla, O. Schmale, and V. Thiel
Biogeosciences, 10, 2725–2735, https://doi.org/10.5194/bg-10-2725-2013, https://doi.org/10.5194/bg-10-2725-2013, 2013
O. Schmale, M. Blumenberg, K. Kießlich, G. Jakobs, C. Berndmeyer, M. Labrenz, V. Thiel, and G. Rehder
Biogeosciences, 9, 4969–4977, https://doi.org/10.5194/bg-9-4969-2012, https://doi.org/10.5194/bg-9-4969-2012, 2012
Related subject area
Biogeochemistry: Organic Biogeochemistry
Elemental stoichiometry of particulate organic matter across the Atlantic Ocean
Lipid remodeling in phytoplankton exposed to multi-environmental drivers in a mesocosm experiment
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Environmental controls on the distribution of brGDGTs and brGMGTs across the Seine River basin (NW France): implications for bacterial tetraethers as a proxy for riverine runoff
Ocean liming effects on dissolved organic matter dynamics
Latitudinal distribution of biomarkers across the western Arctic Ocean and the Bering Sea: an approach to assess sympagic and pelagic algal production
Results from a Multi-Laboratory Ocean Metaproteomic Intercomparison: Effects of LC-MS Acquisition and Data Analysis Procedures
Sinking fate and carbon export of zooplankton fecal pellets: insights from time-series sediment trap observations in the northern South China Sea
Microbial strong organic ligand production is tightly coupled to iron in hydrothermal plumes
Low cobalt inventories in the Amundsen and Ross seas driven by high demand for labile cobalt uptake among native phytoplankton communities
Methods to characterize type, relevance, and interactions of organic matter and microorganisms in fluids along the flow path of a geothermal facility
Potential bioavailability of representative pyrogenic organic matter compounds in comparison to natural dissolved organic matter pools
Distributions of bacteriohopanepolyols in lakes and coastal lagoons of the Azores Archipelago
Recently fixed carbon fuels microbial activity several meters below the soil surface
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Climate and geology overwrite land use effects on soil organic nitrogen cycling on a continental scale
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Microbial labilization and diversification of pyrogenic dissolved organic matter
Bacterial and eukaryotic intact polar lipids point to in situ production as a key source of labile organic matter in hadal surface sediment of the Atacama Trench
What can we learn from amino acids about oceanic organic matter cycling and degradation?
Bacteriohopanetetrol-x: constraining its application as a lipid biomarker for marine anammox using the water column oxygen gradient of the Benguela upwelling system
Active and passive fluxes of carbon, nitrogen, and phosphorus in the northern South China Sea
Cyanobacteria net community production in the Baltic Sea as inferred from profiling pCO2 measurements
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Revised fractional abundances and warm-season temperatures substantially improve brGDGT calibrations in lake sediments
Archaeal intact polar lipids in polar waters: a comparison between the Amundsen and Scotia seas
Reproducible determination of dissolved organic matter photosensitivity
Technical note: Uncovering the influence of methodological variations on the extractability of iron-bound organic carbon
Anthropocene climate warming enhances autochthonous carbon cycling in an upland Arctic lake, Disko Island, West Greenland
Novel hydrocarbon-utilizing soil mycobacteria synthesize unique mycocerosic acids at a Sicilian everlasting fire
Alkenone isotopes show evidence of active carbon concentrating mechanisms in coccolithophores as aqueous carbon dioxide concentrations fall below 7 µmol L−1
Seasonal variability and sources of in situ brGDGT production in a permanently stratified African crater lake
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Better molecular preservation of organic matter in an oxic than in a sulfidic depositional environment: evidence from Thalassiphora pelagica (Dinoflagellata, Eocene) cysts
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The nonconservative distribution pattern of organic matter in the Rajang, a tropical river with peatland in its estuary
Predominance of hexamethylated 6-methyl branched glycerol dialkyl glycerol tetraethers in the Mariana Trench: source and environmental implication
High-pH and anoxic conditions during soil organic matter extraction increases its electron-exchange capacity and ability to stimulate microbial Fe(III) reduction by electron shuttling
Structural elucidation and environmental distributions of butanetriol and pentanetriol dialkyl glycerol tetraethers (BDGTs and PDGTs)
Distribution and degradation of terrestrial organic matter in the sediments of peat-draining rivers, Sarawak, Malaysian Borneo
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Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and parallel factor analysis
Latitudinal variations in δ30Si and δ15N signatures along the Peruvian shelf: quantifying the effects of nutrient utilization versus denitrification over the past 600 years
Diapycnal dissolved organic matter supply into the upper Peruvian oxycline
Composition and vertical flux of particulate organic matter to the oxygen minimum zone of the central Baltic Sea: impact of a sporadic North Sea inflow
Main drivers of transparent exopolymer particle distribution across the surface Atlantic Ocean
Biochemical and structural controls on the decomposition dynamics of boreal upland forest moss tissues
Adam J. Fagan, Tatsuro Tanioka, Alyse A. Larkin, Jenna A. Lee, Nathan S. Garcia, and Adam C. Martiny
Biogeosciences, 21, 4239–4250, https://doi.org/10.5194/bg-21-4239-2024, https://doi.org/10.5194/bg-21-4239-2024, 2024
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Climate change is anticipated to influence the biological pump by altering phytoplankton nutrient distribution. In our research, we collected measurements of particulate matter concentrations during two oceanographic field studies. We observed systematic variations in organic matter concentrations and ratios across the Atlantic Ocean. From statistical modeling, we determined that these variations are associated with differences in the availability of essential nutrients for phytoplankton growth.
Sebastian I. Cantarero, Edgart Flores, Harry Allbrook, Paulina Aguayo, Cristian A. Vargas, John E. Tamanaha, J. Bentley C. Scholz, Lennart T. Bach, Carolin R. Löscher, Ulf Riebesell, Balaji Rajagopalan, Nadia Dildar, and Julio Sepúlveda
Biogeosciences, 21, 3927–3958, https://doi.org/10.5194/bg-21-3927-2024, https://doi.org/10.5194/bg-21-3927-2024, 2024
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Our study explores lipid remodeling in response to environmental stress, specifically how cell membrane chemistry changes. We focus on intact polar lipids in a phytoplankton community exposed to diverse stressors in a mesocosm experiment. The observed remodeling indicates acyl chain recycling for energy storage in intact polar lipids during stress, reallocating resources based on varying growth conditions. This understanding is essential to grasp the system's impact on cellular pools.
Devika Varma, Laura Villanueva, Nicole Bale, Pierre Offre, Gert-Jan Reichart, and Stefan Schouten
EGUsphere, https://doi.org/10.5194/egusphere-2024-1773, https://doi.org/10.5194/egusphere-2024-1773, 2024
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Archaeal hydroxylated tetraether lipids are increasingly used as temperature indicators in marine settings, but the factors influencing their distribution are still unclear. Analyzing membrane lipids of two Thaumarchaeotal strains showed that the growth phase of the cultures does not affect the lipid distribution, but growth temperature profoundly affects the degree of cyclization of these lipids. Also, the abundance of these lipids is species-specific and is not influenced by temperature.
Mengke Wang, Peng Zhang, Huishan Li, Guisen Deng, Deliang Kong, Sifang Kong, and Junjian Wang
Biogeosciences, 21, 2691–2704, https://doi.org/10.5194/bg-21-2691-2024, https://doi.org/10.5194/bg-21-2691-2024, 2024
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We developed and applied complementary analyses to characterize molecular-level carbon traits for water-grown and soil-grown fine roots. The adaptive strategy of developing more labile carbon in water-grown roots accelerated root decomposition and counteracted the decelerated effects of anoxia on decomposition, highlighting an indirect effect of environmental change on belowground carbon cycling.
Zhe-Xuan Zhang, Edith Parlanti, Christelle Anquetil, Jérôme Morelle, Anniet M. Laverman, Alexandre Thibault, Elisa Bou, and Arnaud Huguet
Biogeosciences, 21, 2227–2252, https://doi.org/10.5194/bg-21-2227-2024, https://doi.org/10.5194/bg-21-2227-2024, 2024
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Bacterial tetraethers have important implications for palaeoclimate reconstruction. However, fundamental understanding of how these lipids are transformed from land to sea and which environmental factors influence their distributions is lacking. Here, we investigate the sources of brGDGTs and brGMGTs and the factors controlling their distributions in a large dataset (n=237). We propose a novel proxy (RIX) to trace riverine runoff, which is applicable in modern systems and in paleorecord.
Chiara Santinelli, Silvia Valsecchi, Simona Retelletti Brogi, Giancarlo Bachi, Giovanni Checcucci, Mirco Guerrazzi, Elisa Camatti, Stefano Caserini, Arianna Azzellino, and Daniela Basso
EGUsphere, https://doi.org/10.5194/egusphere-2024-625, https://doi.org/10.5194/egusphere-2024-625, 2024
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To the best of our knowledge, there is no study investigating the impact of ocean liming on dissolved organic matter (DOM) dynamics. Given the central role played by DOM in the microbial loop, a change in its concentration and/or quality has a cascading effect the entire marine ecosystem. Our data clearly show that the addition of hydrated lime cause a reduction in DOM concentration and a change in its quality. The observed effects, detectable at pH 9, becomes significant at pH 10.
Youcheng Bai, Marie-Alexandrine Sicre, Jian Ren, Vincent Klein, Haiyan Jin, and Jianfang Chen
Biogeosciences, 21, 689–709, https://doi.org/10.5194/bg-21-689-2024, https://doi.org/10.5194/bg-21-689-2024, 2024
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Algal biomarkers were used to assess sea ice and pelagic algal production across the western Arctic Ocean with changing sea-ice conditions. They show three distinct areas along with a marked latitudinal gradient of sea ice over pelagic algal production in surface sediments that are reflected by the H-Print index. Our data also show that efficient grazing consumption accounted for the dramatic decrease of diatom-derived biomarkers in sediments compared to that of particulate matter.
Mak A. Saito, Jaclyn K. Saunders, Matthew R. McIlvin, Erin M. Bertrand, John A. Breier, Margaret Mars Brisbin, Sophie M. Colston, Jaimee R. Compton, Tim J. Griffin, W. Judson Hervey, Robert L. Hettich, Pratik D. Jagtap, Michael Janech, Rod Johnson, Rick Keil, Hugo Kleikamp, Dagmar Leary, Lennart Martens, J. Scott P. McCain, Eli Moore, Subina Mehta, Dawn M. Moran, Jaqui Neibauer, Benjamin A. Neely, Michael V. Jakuba, Jim Johnson, Megan Duffy, Gerhard J. Herndl, Richard Giannone, Ryan Mueller, Brook L. Nunn, Martin Pabst, Samantha Peters, Andrew Rajczewski, Elden Rowland, Brian Searle, Tim Van Den Bossche, Gary J. Vora, Jacob R. Waldbauer, Haiyan Zheng, and Zihao Zhao
EGUsphere, https://doi.org/10.5194/egusphere-2023-3148, https://doi.org/10.5194/egusphere-2023-3148, 2024
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The ability to assess the functional capabilities of microbes in the environment is of increasing interest. Metaproteomics, the ability to measure proteins across microbial populations, has been increasing in capability and popularity in recent years. Here, an international team of scientists conducted an intercomparison study using samples collected from the North Atlantic Ocean and observed consistency in the peptides and proteins identified, their functions, and taxonomic origins.
Hanxiao Wang, Zhifei Liu, Jiaying Li, Baozhi Lin, Yulong Zhao, Xiaodong Zhang, Junyuan Cao, Jingwen Zhang, Hongzhe Song, and Wenzhuo Wang
Biogeosciences, 20, 5109–5123, https://doi.org/10.5194/bg-20-5109-2023, https://doi.org/10.5194/bg-20-5109-2023, 2023
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The sinking of zooplankton fecal pellets is a key process in the marine biological carbon pump. This study presents carbon export of four shapes of fecal pellets from two time-series sediment traps in the South China Sea. The results show that the sinking fate of fecal pellets is regulated by marine primary productivity, deep-dwelling zooplankton community, and deep-sea currents in the tropical marginal sea, thus providing a new perspective for exploring the carbon cycle in the world ocean.
Colleen L. Hoffman, Patrick J. Monreal, Justine B. Albers, Alastair J. M. Lough, Alyson E. Santoro, Travis Mellett, Kristen N. Buck, Alessandro Tagliabue, Maeve C. Lohan, Joseph A. Resing, and Randelle M. Bundy
EGUsphere, https://doi.org/10.1101/2023.01.05.522639, https://doi.org/10.1101/2023.01.05.522639, 2023
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Hydrothermally-derived iron can be transported thousands of kilometers away from deep-sea vents, representing a significant flux of vital micronutrients to the ocean. However, the mechanisms that support the stabilization and transport of dissolved iron remain elusive. Using electrochemical methods, advanced mass spectrometry techniques, and genomic tools we demonstrate that strong microbially-produced ligands appear to exert an important control on plume iron biogeochemistry and dissemination.
Rebecca J. Chmiel, Riss M. Kell, Deepa Rao, Dawn M. Moran, Giacomo R. DiTullio, and Mak A. Saito
Biogeosciences, 20, 3997–4027, https://doi.org/10.5194/bg-20-3997-2023, https://doi.org/10.5194/bg-20-3997-2023, 2023
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Cobalt is an important micronutrient for plankton, yet it is often scarce throughout the oceans. A 2017/2018 expedition to coastal Antarctica, including regions of the Amundsen Sea and the Ross Sea, discovered lower concentrations of cobalt compared to two past expeditions in 2005 and 2006, particularly for the type of cobalt preferred as a nutrient by phytoplankton. This loss may be due to changing inputs of other nutrients, causing higher uptake of cobalt by plankton over the last decade.
Alessio Leins, Danaé Bregnard, Andrea Vieth-Hillebrand, Stefanie Poetz, Florian Eichinger, Guillaume Cailleau, Pilar Junier, and Simona Regenspurg
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-159, https://doi.org/10.5194/bg-2023-159, 2023
Revised manuscript accepted for BG
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Organic matter and microbial fluid analyses are rarely taken into account in the geothermal industry and research. However, they can have a significant effect on the efficiency of geothermal power production. We discovered a high variety in organic compound composition in our samples and were able to differentiate it with regard to various sources (e.g. artificial and biogenic). Furthermore, the microbial diversity undergoes significant changes within the flow path of a geothermal power plant.
Emily B. Graham, Hyun-Seob Song, Samantha Grieger, Vanessa A. Garayburu-Caruso, James C. Stegen, Kevin D. Bladon, and Allison N. Myers-Pigg
Biogeosciences, 20, 3449–3457, https://doi.org/10.5194/bg-20-3449-2023, https://doi.org/10.5194/bg-20-3449-2023, 2023
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Intensifying wildfires are increasing pyrogenic organic matter (PyOM) production and its impact on water quality. Recent work indicates that PyOM may have a greater impact on aquatic biogeochemistry than previously assumed, driven by higher bioavailability. We provide a full assessment of the potential bioavailability of PyOM across its chemical spectrum. We indicate that PyOM can be actively transformed within the river corridor and, therefore, may be a growing source of riverine C emissions.
Nora Richter, Ellen C. Hopmans, Danica Mitrović, Pedro M. Raposeiro, Vítor Gonçalves, Ana C. Costa, Linda A. Amaral-Zettler, Laura Villanueva, and Darci Rush
Biogeosciences, 20, 2065–2098, https://doi.org/10.5194/bg-20-2065-2023, https://doi.org/10.5194/bg-20-2065-2023, 2023
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Bacteriohopanepolyols (BHPs) are a diverse class of lipids produced by bacteria across a wide range of environments. This study characterizes the diversity of BHPs in lakes and coastal lagoons in the Azores Archipelago, as well as a co-culture enriched for methanotrophs. We highlight the potential of BHPs as taxonomic markers for bacteria associated with certain ecological niches, which can be preserved in sedimentary records.
Andrea Scheibe, Carlos A. Sierra, and Marie Spohn
Biogeosciences, 20, 827–838, https://doi.org/10.5194/bg-20-827-2023, https://doi.org/10.5194/bg-20-827-2023, 2023
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We explored carbon cycling in soils in three climate zones in Chile down to a depth of 6 m, using carbon isotopes. Our results show that microbial activity several meters below the soil surface is mostly fueled by recently fixed carbon and that strong decomposition of soil organic matter only occurs in the upper decimeters of the soils. The study shows that different layers of the critical zone are tightly connected and that processes in the deep soil depend on recently fixed carbon.
Melissa Sophia Schwab, Hannah Gies, Chantal Valérie Freymond, Maarten Lupker, Negar Haghipour, and Timothy Ian Eglinton
Biogeosciences, 19, 5591–5616, https://doi.org/10.5194/bg-19-5591-2022, https://doi.org/10.5194/bg-19-5591-2022, 2022
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The majority of river studies focus on headwater or floodplain systems, while often neglecting intermediate river segments. Our study on the subalpine Sihl River bridges the gap between streams and lowlands and demonstrates that moderately steep river segments are areas of significant instream alterations, modulating the export of organic carbon over short distances.
Lisa Noll, Shasha Zhang, Qing Zheng, Yuntao Hu, Florian Hofhansl, and Wolfgang Wanek
Biogeosciences, 19, 5419–5433, https://doi.org/10.5194/bg-19-5419-2022, https://doi.org/10.5194/bg-19-5419-2022, 2022
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Cleavage of proteins to smaller nitrogen compounds allows microorganisms and plants to exploit the largest nitrogen reservoir in soils and is considered the bottleneck in soil organic nitrogen cycling. Results from soils covering a European transect show that protein turnover is constrained by soil geochemistry, shifts in climate and associated alterations in soil weathering and should be considered as a driver of soil nitrogen availability with repercussions on carbon cycle processes.
William Kew, Allison Myers-Pigg, Christine Chang, Sean Colby, Josie Eder, Malak Tfaily, Jeffrey Hawkes, Rosalie Chu, and James Stegen
EGUsphere, https://doi.org/10.5194/egusphere-2022-1105, https://doi.org/10.5194/egusphere-2022-1105, 2022
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Natural organic matter (OM) chemistry is often studied with mass spectrometry, but poor use of these data can lead to incorrect outcomes. We review causes of the problems, study them experimentally, and develop a model to guide the use of OM data. We show that the large amount of information from mass spectrometry can overcome technical issues underlying incorrect inferences. The model can guide proper use of mass spectrometry to study OM chemistry, thereby avoiding spurious inferences.
Muhammed Fatih Sert, Helge Niemann, Eoghan P. Reeves, Mats A. Granskog, Kevin P. Hand, Timo Kekäläinen, Janne Jänis, Pamela E. Rossel, Bénédicte Ferré, Anna Silyakova, and Friederike Gründger
Biogeosciences, 19, 2101–2120, https://doi.org/10.5194/bg-19-2101-2022, https://doi.org/10.5194/bg-19-2101-2022, 2022
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We investigate organic matter composition in the Arctic Ocean water column. We collected seawater samples from sea ice to deep waters at six vertical profiles near an active hydrothermal vent and its plume. In comparison to seawater, we found that the organic matter in waters directly affected by the hydrothermal plume had different chemical composition. We suggest that hydrothermal processes may influence the organic matter distribution in the deep ocean.
Charlotte Haugk, Loeka L. Jongejans, Kai Mangelsdorf, Matthias Fuchs, Olga Ogneva, Juri Palmtag, Gesine Mollenhauer, Paul J. Mann, P. Paul Overduin, Guido Grosse, Tina Sanders, Robyn E. Tuerena, Lutz Schirrmeister, Sebastian Wetterich, Alexander Kizyakov, Cornelia Karger, and Jens Strauss
Biogeosciences, 19, 2079–2094, https://doi.org/10.5194/bg-19-2079-2022, https://doi.org/10.5194/bg-19-2079-2022, 2022
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Buried animal and plant remains (carbon) from the last ice age were freeze-locked in permafrost. At an extremely fast eroding permafrost cliff in the Lena Delta (Siberia), we found this formerly frozen carbon well preserved. Our results show that ongoing degradation releases substantial amounts of this carbon, making it available for future carbon emissions. This mobilisation at the studied cliff and also similarly eroding sites bear the potential to affect rivers and oceans negatively.
Aleksandar I. Goranov, Andrew S. Wozniak, Kyle W. Bostick, Andrew R. Zimmerman, Siddhartha Mitra, and Patrick G. Hatcher
Biogeosciences, 19, 1491–1514, https://doi.org/10.5194/bg-19-1491-2022, https://doi.org/10.5194/bg-19-1491-2022, 2022
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Wildfire-derived molecules are ubiquitous in the aquatic environment, but their biological fate remains understudied. We have evaluated the compositional changes that occur to wildfire-derived molecules after incubation with soil microbes. We observe a significant degradation but also a production of numerous new labile molecules. Our results indicate that wildfire-derived molecules can be broken down and the carbon and nitrogen therein can be incorporated into microbial food webs.
Edgart Flores, Sebastian I. Cantarero, Paula Ruiz-Fernández, Nadia Dildar, Matthias Zabel, Osvaldo Ulloa, and Julio Sepúlveda
Biogeosciences, 19, 1395–1420, https://doi.org/10.5194/bg-19-1395-2022, https://doi.org/10.5194/bg-19-1395-2022, 2022
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In this study, we investigate the chemical diversity and abundance of microbial lipids as markers of organic matter sources in the deepest points of the Atacama Trench sediments and compare them to similar lipid stocks in shallower surface sediments and in the overlying water column. We evaluate possible organic matter provenance and some potential chemical adaptations of the in situ microbial community to the extreme conditions of high hydrostatic pressure in hadal realm.
Birgit Gaye, Niko Lahajnar, Natalie Harms, Sophie Anna Luise Paul, Tim Rixen, and Kay-Christian Emeis
Biogeosciences, 19, 807–830, https://doi.org/10.5194/bg-19-807-2022, https://doi.org/10.5194/bg-19-807-2022, 2022
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Amino acids were analyzed in a large number of samples of particulate and dissolved organic matter from coastal regions and the open ocean. A statistical analysis produced two new biogeochemical indicators. An indicator of sinking particle and sediment degradation (SDI) traces the degradation of organic matter from the surface waters into the sediments. A second indicator shows the residence time of suspended matter in the ocean (RTI).
Zoë R. van Kemenade, Laura Villanueva, Ellen C. Hopmans, Peter Kraal, Harry J. Witte, Jaap S. Sinninghe Damsté, and Darci Rush
Biogeosciences, 19, 201–221, https://doi.org/10.5194/bg-19-201-2022, https://doi.org/10.5194/bg-19-201-2022, 2022
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Anaerobic ammonium oxidation (anammox) is an important nitrogen-removal process in the ocean. We assess the distribution of bacteriohopanetetrol-x (BHT-x), used to trace past anammox, along a redox gradient in the water column of the Benguela upwelling system. BHT-x / BHT ratios of >0.18 correspond to the presence of living anammox bacteria and oxygen levels <50 μmol L−1. This allows for a more robust application of BHT-x to trace past marine anammox and deoxygenation in dynamic marine systems.
Jia-Jang Hung, Ching-Han Tung, Zong-Ying Lin, Yuh-ling Lee Chen, Shao-Hung Peng, Yen-Huei Lin, and Li-Shan Tsai
Biogeosciences, 18, 5141–5162, https://doi.org/10.5194/bg-18-5141-2021, https://doi.org/10.5194/bg-18-5141-2021, 2021
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We report measured active and passive fluxes and their controlling mechanisms in the northern South China Sea (NSCS). The total fluxes were higher than most reports in open oceans, indicating the significance of NSCS in atmospheric CO2 uptake and in storing that CO2 in the ocean’s interior. Winter cooling and extreme events enhanced nutrient availability and elevated fluxes. Global warming may have profound impacts on reducing ocean’s uptake and storage of CO2 in subtropical–tropical oceans.
Jens Daniel Müller, Bernd Schneider, Ulf Gräwe, Peer Fietzek, Marcus Bo Wallin, Anna Rutgersson, Norbert Wasmund, Siegfried Krüger, and Gregor Rehder
Biogeosciences, 18, 4889–4917, https://doi.org/10.5194/bg-18-4889-2021, https://doi.org/10.5194/bg-18-4889-2021, 2021
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Based on profiling pCO2 measurements from a field campaign, we quantify the biomass production of a cyanobacteria bloom in the Baltic Sea, the export of which would foster deep water deoxygenation. We further demonstrate how this biomass production can be accurately reconstructed from long-term surface measurements made on cargo vessels in combination with modelled temperature profiles. This approach enables a better understanding of a severe concern for the Baltic’s good environmental status.
Alexander Braun, Marina Spona-Friedl, Maria Avramov, Martin Elsner, Federico Baltar, Thomas Reinthaler, Gerhard J. Herndl, and Christian Griebler
Biogeosciences, 18, 3689–3700, https://doi.org/10.5194/bg-18-3689-2021, https://doi.org/10.5194/bg-18-3689-2021, 2021
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It is known that CO2 fixation by photoautotrophic organisms is the major sink from the atmosphere. While biologists are aware that CO2 fixation also occurs in heterotrophic organisms, this route of inorganic carbon, and its quantitative role, is hardly recognized in biogeochemistry. We demonstrate that a considerable amount of CO2 is fixed annually through anaplerotic reactions in heterotrophic organisms, and a significant quantity of inorganic carbon is temporally sequestered in biomass.
Jonathan H. Raberg, David J. Harning, Sarah E. Crump, Greg de Wet, Aria Blumm, Sebastian Kopf, Áslaug Geirsdóttir, Gifford H. Miller, and Julio Sepúlveda
Biogeosciences, 18, 3579–3603, https://doi.org/10.5194/bg-18-3579-2021, https://doi.org/10.5194/bg-18-3579-2021, 2021
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BrGDGT lipids are a proxy for temperature in lake sediments, but other parameters like pH can influence them, and seasonality can affect the temperatures they record. We find a warm-season bias at 43 new high-latitude sites. We also present a new method that deconvolves the effects of temperature, pH, and conductivity and generate global calibrations for these variables. Our study provides new paleoclimate tools, insight into brGDGTs at the biochemical level, and a new method for future study.
Charlotte L. Spencer-Jones, Erin L. McClymont, Nicole J. Bale, Ellen C. Hopmans, Stefan Schouten, Juliane Müller, E. Povl Abrahamsen, Claire Allen, Torsten Bickert, Claus-Dieter Hillenbrand, Elaine Mawbey, Victoria Peck, Aleksandra Svalova, and James A. Smith
Biogeosciences, 18, 3485–3504, https://doi.org/10.5194/bg-18-3485-2021, https://doi.org/10.5194/bg-18-3485-2021, 2021
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Long-term ocean temperature records are needed to fully understand the impact of West Antarctic Ice Sheet collapse. Glycerol dialkyl glycerol tetraethers (GDGTs) are powerful tools for reconstructing ocean temperature but can be difficult to apply to the Southern Ocean. Our results show active GDGT synthesis in relatively warm depths of the ocean. This research improves the application of GDGT palaeoceanographic proxies in the Southern Ocean.
Alec W. Armstrong, Leanne Powers, and Michael Gonsior
Biogeosciences, 18, 3367–3390, https://doi.org/10.5194/bg-18-3367-2021, https://doi.org/10.5194/bg-18-3367-2021, 2021
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Living things decay into organic matter, which can dissolve into water (like tea brewing). Tea receives its color by absorbing light. Similarly, this material absorbs light, which can then cause chemical reactions that change it. By measuring changes in these optical properties, we found that materials from some places are more sensitive to light than others. Comparing sensitivity to light helps us understand where these materials come from and what happens as they move through water.
Ben J. Fisher, Johan C. Faust, Oliver W. Moore, Caroline L. Peacock, and Christian März
Biogeosciences, 18, 3409–3419, https://doi.org/10.5194/bg-18-3409-2021, https://doi.org/10.5194/bg-18-3409-2021, 2021
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Organic carbon can be protected from microbial degradation in marine sediments through association with iron minerals on 1000-year timescales. Despite the importance of this carbon sink, our spatial and temporal understanding of iron-bound organic carbon interactions globally is poor. Here we show that caution must be applied when comparing quantification of iron-bound organic carbon extracted by different methods as the extraction strength and method specificity can be highly variable.
Mark A. Stevenson, Suzanne McGowan, Emma J. Pearson, George E. A. Swann, Melanie J. Leng, Vivienne J. Jones, Joseph J. Bailey, Xianyu Huang, and Erika Whiteford
Biogeosciences, 18, 2465–2485, https://doi.org/10.5194/bg-18-2465-2021, https://doi.org/10.5194/bg-18-2465-2021, 2021
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We link detailed stable isotope and biomarker analyses from the catchments of three Arctic upland lakes on Disko Island (West Greenland) to a recent dated sediment core to understand how carbon cycling has changed over the past ~500 years. We find that the carbon deposited in sediments in these upland lakes is predominately sourced from in-lake production due to the catchment's limited terrestrial vegetation and elevation and that recent increases in algal production link with climate change.
Nadine T. Smit, Laura Villanueva, Darci Rush, Fausto Grassa, Caitlyn R. Witkowski, Mira Holzheimer, Adriaan J. Minnaard, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 18, 1463–1479, https://doi.org/10.5194/bg-18-1463-2021, https://doi.org/10.5194/bg-18-1463-2021, 2021
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Soils from an everlasting fire (gas seep) in Sicily, Italy, reveal high relative abundances of novel uncultivated mycobacteria and unique 13C-depleted mycocerosic acids (multi-methyl branched fatty acids) close to the main gas seep. Our results imply that mycocerosic acids in combination with their depleted δ13C values offer a new biomarker tool to study the role of soil mycobacteria as hydrocarbon consumers in the modern and past global carbon cycle.
Marcus P. S. Badger
Biogeosciences, 18, 1149–1160, https://doi.org/10.5194/bg-18-1149-2021, https://doi.org/10.5194/bg-18-1149-2021, 2021
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Reconstructing ancient atmospheric CO2 is an important aim of palaeoclimate science in order to understand the Earth's climate system. One method, the alkenone proxy based on molecular fossils of coccolithophores, has been recently shown to be ineffective at low-to-moderate CO2 levels. In this paper I show that this is likely due to changes in the biogeochemistry of the coccolithophores when there is low carbon availability, but for much of the Cenozoic the alkenone proxy should have utility.
Loes G. J. van Bree, Francien Peterse, Allix J. Baxter, Wannes De Crop, Sigrid van Grinsven, Laura Villanueva, Dirk Verschuren, and Jaap S. Sinninghe Damsté
Biogeosciences, 17, 5443–5463, https://doi.org/10.5194/bg-17-5443-2020, https://doi.org/10.5194/bg-17-5443-2020, 2020
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Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are used as a paleothermometer based on their temperature dependence in global soils, but aquatic production complicates their use in lakes. BrGDGTs in the water column of Lake Chala, East Africa, respond to oxygen conditions and mixing. Changes in their signal can be linked to bacterial community composition rather than membrane adaptation to changing conditions. Their integrated signal in the sediment reflects mean air temperature.
Alexandra N. Loginova, Andrew W. Dale, Frédéric A. C. Le Moigne, Sören Thomsen, Stefan Sommer, David Clemens, Klaus Wallmann, and Anja Engel
Biogeosciences, 17, 4663–4679, https://doi.org/10.5194/bg-17-4663-2020, https://doi.org/10.5194/bg-17-4663-2020, 2020
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We measured dissolved organic carbon (DOC), nitrogen (DON) and matter (DOM) optical properties in pore waters and near-bottom waters of the eastern tropical South Pacific off Peru. The difference between diffusion-driven and net fluxes of DOC and DON and qualitative changes in DOM optical properties suggested active microbial utilisation of the released DOM at the sediment–water interface. Our results suggest that the sediment release of DOM contributes to microbial processes in the area.
Gerard J. M. Versteegh, Alexander J. P. Houben, and Karin A. F. Zonneveld
Biogeosciences, 17, 3545–3561, https://doi.org/10.5194/bg-17-3545-2020, https://doi.org/10.5194/bg-17-3545-2020, 2020
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Anoxic sediments mostly contain much more organic matter than oxic ones, and therefore organic matter in anoxic settings is often considered to be preserved better than in oxic settings. However, through the analysis of the same fossil dinoflagellate cyst species from both oxic and anoxic settings, we show that at a molecular level the preservation in the oxic sediments may be better since in the anoxic setting the cyst macromolecule has been altered by postdepositional modification.
Jingjing Guo, Miriam Glendell, Jeroen Meersmans, Frédérique Kirkels, Jack J. Middelburg, and Francien Peterse
Biogeosciences, 17, 3183–3201, https://doi.org/10.5194/bg-17-3183-2020, https://doi.org/10.5194/bg-17-3183-2020, 2020
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The fluxes of soil organic carbon (OC) transport from land to sea are poorly constrained, mostly due to the lack of a specific tracer for soil OC. Here we evaluate the use of specific molecules derived from soil bacteria as a tracer for soil OC in a small river catchment. We find that the initial soil signal is lost upon entering the aquatic environment. However, the local environmental history of the catchment is reflected by these molecules in the lake sediments that act as their sink.
Zhuo-Yi Zhu, Joanne Oakes, Bradley Eyre, Youyou Hao, Edwin Sien Aun Sia, Shan Jiang, Moritz Müller, and Jing Zhang
Biogeosciences, 17, 2473–2485, https://doi.org/10.5194/bg-17-2473-2020, https://doi.org/10.5194/bg-17-2473-2020, 2020
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Samples were collected in August 2016 in the Rajang River and its estuary, with tropical forest in the river basin and peatland in the estuary. Organic matter composition was influenced by transportation in the river basin, whereas peatland added clear biodegraded parts to the fluvial organic matter, which implies modification of the initial lability and/or starting points in the subsequent degradation and alternation processes after the organic matter enters the sea.
Wenjie Xiao, Yasong Wang, Yongsheng Liu, Xi Zhang, Linlin Shi, and Yunping Xu
Biogeosciences, 17, 2135–2148, https://doi.org/10.5194/bg-17-2135-2020, https://doi.org/10.5194/bg-17-2135-2020, 2020
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The hadal zone (6–11 km depth) is the least explored habitat on Earth. We studied microbial branched glycerol dialkyl glycerol tetraethers (brGDGTs) in the Challenger Deep, Mariana Trench. One unique feature is the strong predominance of 6-methyl brGDGT, which likely reflects an adaption of brGDGT-producing bacteria to alkaline seawater and low temperature. BrGDGTs, with elemental and isotopic data, suggest an autochthonous product for brGDGT. A new approach is proposed for brGDGT sourcing.
Yuge Bai, Edisson Subdiaga, Stefan B. Haderlein, Heike Knicker, and Andreas Kappler
Biogeosciences, 17, 683–698, https://doi.org/10.5194/bg-17-683-2020, https://doi.org/10.5194/bg-17-683-2020, 2020
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Biogeochemical processes of SOM are key for greenhouse gas emission and water quality. We extracted SOM by water or by NaOH–HCl under oxic–anoxic conditions. Chemical and anoxic extractions lead to higher SOM electron exchange capacities, resulting in stimulation of microbial Fe(III) reduction. Therefore, aqueous pH-neutral SOM extracts should be used to reflect environmental SOM redox processes, and artifacts of chemical extractions need to be considered when evaluating SOM redox processes.
Sarah Coffinet, Travis B. Meador, Lukas Mühlena, Kevin W. Becker, Jan Schröder, Qing-Zeng Zhu, Julius S. Lipp, Verena B. Heuer, Matthew P. Crump, and Kai-Uwe Hinrichs
Biogeosciences, 17, 317–330, https://doi.org/10.5194/bg-17-317-2020, https://doi.org/10.5194/bg-17-317-2020, 2020
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This study deals with two membrane lipids called BDGTs and PDGTs. Membrane lipids are molecules forming the cell envelope of all organisms. Different organisms produce different lipids thus they can be used to detect the presence of specific organisms in the environment. We analyzed the structure of these new lipids and looked for potential producers. We found that they are likely made by microbes emitting methane below the sediment surface and could be used to track these specific microbes.
Ying Wu, Kun Zhu, Jing Zhang, Moritz Müller, Shan Jiang, Aazani Mujahid, Mohd Fakharuddin Muhamad, and Edwin Sien Aun Sia
Biogeosciences, 16, 4517–4533, https://doi.org/10.5194/bg-16-4517-2019, https://doi.org/10.5194/bg-16-4517-2019, 2019
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Our understanding of terrestrial organic matter (TOM) in tropical peat-draining rivers remains limited, especially in Southeast Asia. We explored the characteristics of TOM via bulk parameters and lignin phenols of sediment in Malaysia. This showed that the most important plant source of the organic matter in these rivers is woody angiosperm C3 plants with limited diagenetic alteration. This slower degradation of TOM may be a link to higher total nitrogen content, especially for the small river.
Caitlyn R. Witkowski, Sylvain Agostini, Ben P. Harvey, Marcel T. J. van der Meer, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 16, 4451–4461, https://doi.org/10.5194/bg-16-4451-2019, https://doi.org/10.5194/bg-16-4451-2019, 2019
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Carbon dioxide concentrations (pCO2) in the atmosphere play an integral role in Earth system dynamics, especially climate. Past climates help us understand future ones, but reconstructing pCO2 over the geologic record remains a challenge. This research demonstrates new approaches for exploring past pCO2 via the carbon isotope fractionation in general algal lipids, which we test over a high CO2 gradient from a naturally occurring CO2 seep.
Yongli Zhou, Patrick Martin, and Moritz Müller
Biogeosciences, 16, 2733–2749, https://doi.org/10.5194/bg-16-2733-2019, https://doi.org/10.5194/bg-16-2733-2019, 2019
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We found that peatlands in coastal Sarawak, Borneo, export extremely humified organic matter, which dominates the riverine organic matter pool and conservatively mixes with seawater, while the freshly produced fraction is low and stable in concentration at all salinities. We estimated that terrigenous fractions, which showed high photolability, still account for 20 % of the coastal dissolved organic carbon pool, implying the importance of peat-derived organic matter in the coastal carbon cycle.
Kristin Doering, Claudia Ehlert, Philippe Martinez, Martin Frank, and Ralph Schneider
Biogeosciences, 16, 2163–2180, https://doi.org/10.5194/bg-16-2163-2019, https://doi.org/10.5194/bg-16-2163-2019, 2019
Alexandra N. Loginova, Sören Thomsen, Marcus Dengler, Jan Lüdke, and Anja Engel
Biogeosciences, 16, 2033–2047, https://doi.org/10.5194/bg-16-2033-2019, https://doi.org/10.5194/bg-16-2033-2019, 2019
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High primary production in the Peruvian upwelling system is followed by rapid heterotrophic utilization of organic matter and supports the formation of one of the most intense oxygen minimum zones (OMZs) in the world. Here, we estimated vertical fluxes of oxygen and dissolved organic matter (DOM) from the surface to the OMZ. Our results suggest that DOM remineralization substantially reduces oxygen concentration in the upper water column and controls the shape of the upper oxycline.
Carolina Cisternas-Novoa, Frédéric A. C. Le Moigne, and Anja Engel
Biogeosciences, 16, 927–947, https://doi.org/10.5194/bg-16-927-2019, https://doi.org/10.5194/bg-16-927-2019, 2019
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We investigate the composition and vertical fluxes of POM in two deep basins of the Baltic Sea (GB: Gotland Basin and LD: Landsort Deep). The two basins showed different O2 regimes resulting from the intrusion of oxygen-rich water from the North Sea that ventilated the deep waters in GB, but not in LD.
In GB, O2 intrusions lead to a high abundance of manganese oxides that aggregate with POM, altering its composition and vertical flux and contributing to a higher POC transfer efficiency in GB.
Marina Zamanillo, Eva Ortega-Retuerta, Sdena Nunes, Pablo Rodríguez-Ros, Manuel Dall'Osto, Marta Estrada, Maria Montserrat Sala, and Rafel Simó
Biogeosciences, 16, 733–749, https://doi.org/10.5194/bg-16-733-2019, https://doi.org/10.5194/bg-16-733-2019, 2019
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Many marine microorganisms produce polysaccharide-rich transparent exopolymer particles (TEPs) for rather unknown reasons but with important consequences for the ocean carbon cycle, sea–air gas exchange and formation of organic aerosols. Here we compare surface–ocean distributions of TEPs and physical, chemical and biological variables along a N–S transect in the Atlantic Ocean. Our data suggest that phytoplankton and not bacteria are the main TEP producers, and solar radiation acts as a sink.
Michael Philben, Sara Butler, Sharon A. Billings, Ronald Benner, Kate A. Edwards, and Susan E. Ziegler
Biogeosciences, 15, 6731–6746, https://doi.org/10.5194/bg-15-6731-2018, https://doi.org/10.5194/bg-15-6731-2018, 2018
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We explored the relationship between chemical composition and the temperature sensitivity of moss decomposition using 959-day lab incubations. Mass loss was low despite the predominance of carbohydrates, indicating the persistence of labile C. Scanning electron microscopy revealed little change in the moss cell-wall structure. These results suggest that the moss cell-wall matrix protects labile C from decomposition, contributing to the globally important stocks of moss-derived C.
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Short summary
Today, sterols are widespread in plants, animals, and fungi but are almost absent in the oldest rocks. Microbial mats, representing the earliest complex ecosystems on Earth, were omnipresent in Precambrian marine environments and may have degraded the sterols at that time. Here we analyze the distribution of sterols through a microbial mat. This provides insight into how variations in biological and nonbiological factors affect the preservation of sterols in modern and ancient microbial mats.
Today, sterols are widespread in plants, animals, and fungi but are almost absent in the oldest...
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