Assimilation of Particular Organic Matter and Dissolved Organic or Inorganic Compounds by Cribroelphidium selseyense (Foraminifera)

Autor(en)
Michael Lintner, Bianca Lintner, Wolfgang Wanek, Sarina Schmidt, Nina Keul, Petra Heinz
Abstrakt

Marine carbon and nitrogen processing through microorganisms’ metabolism is an important aspect of the global element cycles. For that purpose, we used foraminifera to analyze the element turnover with different algae food sources. In the Baltic Sea, benthic foraminifera are quite common and therefore it is important to understand their metabolism. Especially, Cribroelphidium selseyense, also occurring in the Baltic Sea, has often been used for laboratory feeding experiments to test their effect on carbon or nitrogen turnover. Therefore, foraminifera were collected from the Kiel Fjord and fed with six different algal species in two qualities (freeze-dried algae vs. fresh algae, all 13C- and 15N-labeled). Also, labeled dissolved inorganic C and N compounds and glucose were offered to the foraminifera to test direct assimilation of dissolved compounds (carbon and nitrogen) from the water column. Our experiments showed that after 15 days of incubation, there were highly significant differences in isotope labeling in foraminifera fed with fresh algae and dry algae, depending on algal species. Further, different algal species led to different 13C and 15N enrichment in the studied foraminifera, highlighting a feeding preference for one diatom species and an Eustigmatophyte. A significant carbon assimilation from HCO3– was observed after 7 days of incubation. The N assimilation from NH4+ was significantly higher than for NO3– as an inorganic N source. The uptake of glucose showed a lag phase, which was often observed during past experiments, where foraminifera were in a steady state and showed no food uptake at regular intervals. These results highlight the importance of food quality on the feeding behavior and metabolic pathways for further studies of foraminiferal nutrition and nutrient cycling.

Organisation(en)
Institut für Paläontologie, Department für Mikrobiologie und Ökosystemforschung
Externe Organisation(en)
GEOMAR Helmholtz-Zentrum für Ozeanforschung, Christian-Albrechts-Universität zu Kiel
Journal
Frontiers in Marine Science
Band
8
Anzahl der Seiten
12
DOI
https://doi.org/10.3389/fmars.2021.778148
Publikationsdatum
11-2021
Peer-reviewed
Ja
ÖFOS 2012
106026 Ökosystemforschung
Schlagwörter
ASJC Scopus Sachgebiete
Water Science and Technology, Environmental Science (miscellaneous), Ocean Engineering, Aquatic Science, Oceanography, Global and Planetary Change
Sustainable Development Goals
SDG 14 – Leben unter Wasser
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/2044ad6a-bc5e-4bfa-8b7e-2ca504e04a23