Molecular Signatures of Biogeochemical Transformations in Dissolved Organic Matter from Ten World Rivers
Riedel, T., Zark, M., Vähätalo, A., Niggemann, J., Spencer, R. G. M., Hernes, P. J., & Dittmar, T. (2016). Molecular Signatures of Biogeochemical Transformations in Dissolved Organic Matter from Ten World Rivers. Frontiers in Earth Science, 4, Article 85. https://doi.org/10.3389/feart.2016.00085
Published inFrontiers in Earth Science
© 2016 Riedel, Zark, Vähätalo, Niggemann, Spencer, Hernes and Dittmar. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).
Rivers carry large amounts of dissolved organic matter (DOM) to the oceans thereby connecting terrestrial and marine element cycles. Photo-degradation in conjunction with microbial turnover is considered a major pathway by which terrigenous DOM is decomposed. To reveal globally relevant patterns behind this process, we performed photo-degradation experiments and year-long bio-assays on DOM from ten of the largest world rivers that collectively account for more than one-third of the fresh water discharge to the global ocean. We furthermore tested the hypothesis that the terrigenous component in deep-sea DOM may be far higher than biomarker studies suggest, because of the selective photochemical destruction of characteristic biomolecules from vascular plants. DOM was molecularly characterized by a combination of non-targeted ultrahigh-resolution mass spectrometry and quantitative molecular tracer analyses. We show that the reactivity of DOM is globally related to broad catchment properties. Basins that are dominated by forest and grassland export more photo-degradable DOM than other rivers. Chromophoric compounds are mainly vascular plant-derived polyphenols, and partially carry a pyrogenic signature from vegetation fires. These forest and grassland dominated rivers lost up to 50% of dissolved organic carbon (DOC) during irradiation, and up to 85% of DOC was lost in total if subsequently bio-incubated for 1 year. Basins covered by cropland, on the other hand, export DOM with a higher proportion of photo-resistant and bio-available DOM which is enriched in nitrogen. In these rivers, 30% or less of DOC was photodegraded. Consistent with previous studies, we found that riverine DOM resembled marine DOM in its broad molecular composition after extensive degradation, mainly due to almost complete removal of aromatics. More detailed molecular fingerprinting analysis (based on the relative abundance of >4000 DOM molecular formulas), however, revealed clear differences between degraded riverine and deep-sea DOM (molecular Bray-Curtis dissimilarity of ~50%). None of our experimental treatments enhanced the molecular similarity between the rivers and the deep ocean. We conclude that terrigenous DOM retains a specific molecular signature during photo-degradation on much longer time scales than previously assumed and that substantial, thus far unknown, molecular transformations occur prior to downward convection into the deep oceanic basins. ...
PublisherFrontiers Research Foundation
ISSN Search the Publication Forum2296-6463
Publication in research information system
MetadataShow full item record
Except where otherwise noted, this item's license is described as © 2016 Riedel, Zark, Vähätalo, Niggemann, Spencer, Hernes and Dittmar. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).
Showing items with similar title or keywords.
The effect of iron on the biodegradation of natural dissolved organic matter Xiao, Yihua; Hoikkala, Laura; Kasurinen, Ville; Tiirola, Marja; Kortelainen, Pirkko; Vähätalo, Anssi (Wiley-Blackwell Publishing, Inc., 2016)Iron (Fe) may alter the biodegradation of dissolved organic matter (DOM), by interacting with DOM, phosphorus (P), and microbes. We isolated DOM and a bacterial community from boreal lake water and examined bacterial growth ...
Carbon budget and molecular structure of natural organic matter in bank infiltrated groundwater Jylhä‐Ollila, Maija; Laine‐Kaulio, Hanne; Schilder, Jos; Niinikoski‐Fuβwinkel, Paula; Kekäläinen, Timo; Jänis, Janne; Koivusalo, Harri (Wiley-Blackwell, 2021)Managed aquifer recharge (MAR) provides means to remove natural organic matter (NOM) from surface waters. Recent studies have explored the degree of NOM removal in groundwater. In this study, we further elaborate the NOM ...
Organic material dissolved during oxygen-alkali pulping of hot-water-extracted spruce sawdust Lehto, Joni; Alén, Raimo (North Carolina State University, 2016)Untreated and hot-water-extracted (HWE) Norway spruce (Picea abies) sawdust was cooked using the sulfur-free oxygen-alkali (OA) method under the following conditions: temperature, 170 °C; liquor-to-wood ratio, 5:1 L/kg; ...
Activated carbon from hydrolysis lignin : Effect of activation method on carbon properties Bergna, Davide; Varila, Toni; Romar, Henrik; Lassi, Ulla (Elsevier BV, 2022)This study presents the effects of different activation methods to produce activated carbon from the hydrolysis lignin. Pretreatment of the feedstock with common mineral acids (HCL, HNO3, and H3PO4), different steam rates ...
Superoxide-driven autocatalytic dark production of hydroxyl radicals in the presence of complexes of natural dissolved organic matter and iron Xiao, Yihua; Carena, Luca; Näsi, Marja-Terttu; Vähätalo, Anssi V. (Elsevier, 2020)We introduced superoxide as potassium superoxide (KO2) to artificial lake water containing dissolved organic matter (DOM) without or with introduced ferric iron complexes (DOM-Fe), and monitored the production rate of ...