The stable carbon isotope signature of methane produced by saprotrophic fungi

• Verfasst von: Schroll, Moritz [VerfasserIn]
• Verfasst von: Keppler, Frank [VerfasserIn]
• Verfasst von: Greule, Markus [VerfasserIn]
• Verfasst von: Eckhardt, Christian [VerfasserIn]
• Verfasst von: Zorn, Holger [VerfasserIn]
• Verfasst von: Lenhart, Katharina [VerfasserIn]
• Titel: The stable carbon isotope signature of methane produced by saprotrophic fungi
• Verf.angabe: Moritz Schroll, Frank Keppler, Markus Greule, Christian Eckhardt, Holger Zorn, Katharina Lenhart
• E-Jahr: 2020
• Jahr: 2 April 2020
• Umfang: 21 S.
• Fussnoten: Gesehen am 29.06.2020
• Titel Quelle: Enthalten in: Biogeosciences discussions
• Ort Quelle: Katlenburg-Lindau [u.a.] : Copernicus, 2004
• Jahr Quelle: 2020
• Band/Heft Quelle: (2020) Preprint, Seite 1-21, 21 Seiten
• ISSN Quelle: 1810-6285
• DOI: doi:10.5194/bg-2020-108
• Datenträger: Online-Ressource
• Sprache: eng
• Bibliogr. Hinweis: Forschungsdaten: Schroll, Moritz: The stable carbon isotope signature of methane produced by saprotrophic fungi [Dataset]
• K10plus-PPN: 1702883086

Abstract

<p><strong>Abstract.</strong> Methane (CH₄) is the most abundant organic compound in the atmosphere with emissions from many biotic and abiotic sources. Recent studies have shown that CH₄ production occurs under aerobic conditions in eukaryotes such as plants, animals, algae and saprotrophic fungi. Saprotrophic fungi play an important role in nutrient recycling in terrestrial ecosystems by their ability to decompose plant litter. Even though the CH₄ production by saprotrophic fungi has been reported, so far, no data for stable carbon isotope values of the emitted CH4 (δ¹³C-CH₄ values) is available. In this study we measured the δ¹³C values of CH₄ and carbon dioxide (δ¹³C-CO₂ values) emitted by the two saprotrophic fungi Pleurotus sapidus and Laetiporus sulphureus cultivated on three different substrates pine wood, grass and corn, reflecting both C₃ and C₄ plants with distinguished bulk δ¹³C values. Applying keeling plots, we found that the δ¹³C source values of CH₄ emitted from fungi cover a wide range from &minus;40 mUr to &minus;69 mUr depending on the growth substrate and fungal species. Whilst little apparent carbon isotopic fractionation (in the range of &minus;0.3 mUr to 4.6 mUr) was calculated for δ¹³C values of CO₂ released from P. sapidus and L. sulphureus relative to the bulk δ¹³C values of the growth substrates, much larger carbon isotopic fractionations (ranging from &minus;22 mUr to &minus;42 mUr) were observed for the formation of CH₄. Whilst the two fungal species showed similar δ¹³CH₄ source values when grown on pine wood, δ¹³CH₄ source values differed substantially between the two fungal species when grown on grass or corn. We found that δ¹³CH₄ source values emitted by saprotrophic fungi are highly dependent on the fungal species and the metabolized substrate. They cover a broad range of δ¹³CH₄ values and overlap with values reported for methanogenic archaea, thermogenic degradation of organic matter and other eukaryotes.</p>