Kleptoplastidic benthic foraminifera from aphotic habitats: insights into assimilation of inorganic C, N and S studied with sub-cellular resolution.

Autor: Jauffrais T; UMR CNRS 6112 LPG-BIAF, Université d'Angers, 2 Boulevard Lavoisier, 49045, Angers Cedex 1, France.; Ifremer, RBE/LEAD, 101 Promenade Roger Laroque, 98897, Nouméa, New Caledonia., LeKieffre C; UMR CNRS 6112 LPG-BIAF, Université d'Angers, 2 Boulevard Lavoisier, 49045, Angers Cedex 1, France.; Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland., Schweizer M; UMR CNRS 6112 LPG-BIAF, Université d'Angers, 2 Boulevard Lavoisier, 49045, Angers Cedex 1, France., Geslin E; UMR CNRS 6112 LPG-BIAF, Université d'Angers, 2 Boulevard Lavoisier, 49045, Angers Cedex 1, France., Metzger E; UMR CNRS 6112 LPG-BIAF, Université d'Angers, 2 Boulevard Lavoisier, 49045, Angers Cedex 1, France., Bernhard JM; Woods Hole Oceanographic Institution, Geology & Geophysics Department, Woods Hole, MA, USA., Jesus B; EA2160, Laboratoire Mer Molécules Santé, Université de Nantes, Nantes, France.; BioISI - Biosystems & Integrative Sciences Institute, Campo Grande University of Lisboa, Faculty of Sciences, Lisbon, Portugal., Filipsson HL; Department of Geology, Lund University, Sölvegatan 12, 223 62, Lund, Sweden., Maire O; Univ. Bordeaux, EPOC, UMR 5805, 33400, Talence, France.; CNRS, EPOC, UMR 5805, 33400, Talence, France., Meibom A; Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.; Center for Advanced Surface Analysis, Institute of Earth Sciences, University of Lausanne, 1015, Lausanne, Switzerland.
Jazyk: angličtina
Zdroj: Environmental microbiology [Environ Microbiol] 2019 Jan; Vol. 21 (1), pp. 125-141. Date of Electronic Publication: 2018 Oct 25.
DOI: 10.1111/1462-2920.14433
Abstrakt: The assimilation of inorganic compounds in foraminiferal metabolism compared to predation or organic matter assimilation is unknown. Here, we investigate possible inorganic-compound assimilation in Nonionellina labradorica, a common kleptoplastidic benthic foraminifer from Arctic and North Atlantic sublittoral regions. The objectives were to identify the source of the foraminiferal kleptoplasts, assess their photosynthetic functionality in light and darkness and investigate inorganic nitrogen and sulfate assimilation. We used DNA barcoding of a ~ 830 bp fragment from the SSU rDNA to identify the kleptoplasts and correlated transmission electron microscopy and nanometre-scale secondary ion mass spectrometry (TEM-NanoSIMS) isotopic imaging to study 13 C-bicarbonate, 15 N-ammonium and 34 S-sulfate uptake. In addition, respiration rate measurements were determined to assess the response of N. labradorica to light. The DNA sequences established that over 80% of the kleptoplasts belonged to Thalassiosira (with 96%-99% identity), a cosmopolitan planktonic diatom. TEM-NanoSIMS imaging revealed degraded cytoplasm and an absence of 13 C assimilation in foraminifera exposed to light. Oxygen measurements showed higher respiration rates under light than dark conditions, and no O 2 production was detected. These results indicate that the photosynthetic pathways in N. labradorica are not functional. Furthermore, N. labradorica assimilated both 15 N-ammonium and 34 S-sulfate into its cytoplasm, which suggests that foraminifera might have several ammonium or sulfate assimilation pathways, involving either the kleptoplasts or bona fide foraminiferal pathway(s) not yet identified.
(© 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.)
Databáze: MEDLINE
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