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

Jauffrais, Thierry ; LeKieffre, Charlotte ; Schweizer, Magali ; Geslin, Emmanuelle ; Metzger, Edouard ; Bernhard, Joan M. ; Jesus, Bruno ; Filipsson, Helena L. LU orcid ; Maire, Olivier and Meibom, Anders (2019) In Environmental Microbiology 21(1). p.125-141
Abstract
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... (More)
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 13C-bicarbonate, 15N-ammonium and 34S-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 13C assimilation in foraminifera exposed to light. Oxygen measurements showed higher respiration rates under light than dark conditions, and no O2 production was detected. These results indicate that the photosynthetic pathways in N. labradorica are not functional. Furthermore, N. labradorica assimilated both 15N-ammonium and 34S-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. (Less)
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author
; ; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Environmental Microbiology
volume
21
issue
1
pages
125 - 141
publisher
Wiley-Blackwell
external identifiers
  • pmid:30277305
  • scopus:85055527658
ISSN
1462-2912
DOI
10.1111/1462-2920.14433
project
Svenska kalkskaliga mikroorganismer i franska akvarier
language
English
LU publication?
yes
id
18cabc60-c21d-4c22-95c8-5cbe40daaba8
date added to LUP
2018-11-12 12:16:18
date last changed
2024-03-02 10:57:12
@article{18cabc60-c21d-4c22-95c8-5cbe40daaba8,
  abstract     = {{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 13C-bicarbonate, 15N-ammonium and 34S-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 13C assimilation in foraminifera exposed to light. Oxygen measurements showed higher respiration rates under light than dark conditions, and no O2 production was detected. These results indicate that the photosynthetic pathways in N. labradorica are not functional. Furthermore, N. labradorica assimilated both 15N-ammonium and 34S-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.}},
  author       = {{Jauffrais, Thierry and LeKieffre, Charlotte and Schweizer, Magali and Geslin, Emmanuelle and Metzger, Edouard and Bernhard, Joan M. and Jesus, Bruno and Filipsson, Helena L. and Maire, Olivier and Meibom, Anders}},
  issn         = {{1462-2912}},
  language     = {{eng}},
  number       = {{1}},
  pages        = {{125--141}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Environmental Microbiology}},
  title        = {{Kleptoplastidic benthic foraminifera from aphotic habitats : insights into assimilation of inorganic C, N and S studied with sub-cellular resolution}},
  url          = {{http://dx.doi.org/10.1111/1462-2920.14433}},
  doi          = {{10.1111/1462-2920.14433}},
  volume       = {{21}},
  year         = {{2019}},
}