A1 Journal article (refereed)
The influence of lipid content and taxonomic affiliation on methane and carbon dioxide production from phytoplankton biomass in lake sediment (2021)

Hiltunen, M., Nykänen, H., & Syväranta, J. (2021). The influence of lipid content and taxonomic affiliation on methane and carbon dioxide production from phytoplankton biomass in lake sediment. Limnology and Oceanography, 66(5), 1915-1925. https://doi.org/10.1002/lno.11732

JYU authors or editors

Publication details

All authors or editors: Hiltunen, Minna; Nykänen, Hannu; Syväranta, Jari

Journal or series: Limnology and Oceanography

ISSN: 0024-3590

eISSN: 1939-5590

Publication year: 2021

Volume: 66

Issue number: 5

Pages range: 1915-1925

Publisher: John Wiley & Sons

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1002/lno.11732

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/75088

Abstract

The greenhouse gases methane (CH4) and carbon dioxide (CO2) are end products of microbial anaerobic degradation of organic matter (OM) in lake sediments. Although previous research has shown that phytoplankton lipid content influences sediment methanogenesis, current understanding on how OM quality affects methanogenesis is still limited. Such information is needed to more accurately assess how lake greenhouse gas emissions may change in response to anthropogenic activities. We cultured 11 phytoplankton species from five classes and studied how taxonomic identity, C : N ratio, lipid content, and fatty acid composition of phytoplankton biomass affects the CH4 and net CO2 production in anaerobic lake sediments with an incubation experiment that lasted > 100 d. The carbon‐normalized potential CH4 (0.09–0.23 μmol mg C−1 d−1) and net CO2 (0.09–0.28 μmol mg C−1 d−1) production rates were not related to phytoplankton taxonomic affiliation (e.g., class, species), C : N ratio, or fatty acid composition of algal biomass. Methane or net CO2 production potentials did not increase with higher lipid content (10–30%); however, total fatty acid content had a weak correlation with CH4 production potential. In contrast to previous research, our results suggest that lipid content is of minor importance in determining methanogenesis rates from the biomass of multispecies phytoplankton communities settling on sediments. The decrease in CO2 concentration and the correlation between stable carbon isotope signatures of CH4 and molar ratio of CH4 and CO2 at the end of the experiment may indicate that importance of hydrogenotrophic methanogenesis, which uses CO2 when other substrates become limiting, increased during the long incubation.

Keywords: lakes; carbon cycle; greenhouse gases; methane; carbon dioxide; plankton; microalgae; nutrients (plants); lipids; sediments; limnology

Free keywords: limnology; methane; carbon dioxide; phytoplankton biomass; lake sediment

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Ministry reporting: Yes

Reporting Year: 2021

Preliminary JUFO rating: 2