Johanna Bergkvist
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Johanna Bergkvist has a total of 14 co-authors. Here are the top co-authors by number of shared publications:
- Anna Reunamo
Department of Biology, Division of Genetics and Physiology, University of Turku, FI-20014 Turku, Finland
1 shared publication - Carsten Paul
Department for Bioorganic Analytics, Friedrich Schiller University Jena, 07743 Jena, Germany
1 shared publication - Elin Lindehoff
Umeå Marine Sciences Centre, Umeå University, 91020 Hörnefors, Sweden
1 shared publication Erik Selander
National Institute for Aquatic Resources, Denmark's Technical University, Charlottenlund Slot, Charlottenlund, Denmark
1 shared publication- Georg Pohnert
Friedrich Schiller University Jena
1 shared publication - Hannes Richter
Department for Bioorganic Analytics, Friedrich Schiller University Jena, 07743 Jena, Germany
1 shared publication
Latest Publications
- Open Access
- 28 March 2012
- Published by MDPI AG in Marine Drugs
- Vol. 10 (4) , 775-792
Diatom Derived Polyunsaturated Aldehydes Do Not Structure the Planktonic Microbial Community in a Mesocosm Study
Several marine and freshwater diatoms produce polyunsaturated aldehydes (PUA) in wound-activated processes. These metabolites are also released by intact diatom cells during algal blooms. Due to their activity in laboratory experiments, PUA are considered as potential mediators of diatom-bacteria interactions. Here, we tested the hypothesis that PUA mediate such processes in a close-to-field mesocosm experiment. Natural plankton communities enriched with Skeletonema marinoi strains that differ in their PUA production, a plankton control, and a plankton control supplemented with PUA at natural and elevated concentrations were observed. We monitored bacterial and viral abundance as well as bacterial community composition and did not observe any influence of PUA on these parameters even at elevated concentrations. We rather detected an alternation of the bacterial diversity over time and differences between the two S. marinoi strains, indicating unique dynamic bacterial communities in these algal blooms. These results suggest that factors other than PUA are of significance for interactions between diatoms and bacteria.
- 28 March 2012
- Published by MDPI AG in Marine Drugs
- Vol. 10 (4) , 775-792
Open AccessDiatom Derived Polyunsaturated Aldehydes Do Not Structure the Planktonic Microbial Community in a Mesocosm Study
Several marine and freshwater diatoms produce polyunsaturated aldehydes (PUA) in wound-activated processes. These metabolites are also released by intact diatom cells during algal blooms. Due to their activity in laboratory experiments, PUA are considered as potential mediators of diatom-bacteria interactions. Here, we tested the hypothesis that PUA mediate such processes in a close-to-field mesocosm experiment. Natural plankton communities enriched with Skeletonema marinoi strains that differ in their PUA production, a plankton control, and a plankton control supplemented with PUA at natural and elevated concentrations were observed. We monitored bacterial and viral abundance as well as bacterial community composition and did not observe any influence of PUA on these parameters even at elevated concentrations. We rather detected an alternation of the bacterial diversity over time and differences between the two S. marinoi strains, indicating unique dynamic bacterial communities in these algal blooms. These results suggest that factors other than PUA are of significance for interactions between diatoms and bacteria.
- 16 January 2012
- Published by Wiley in Limnology and Oceanography
- Vol. 57 (1) , 318-324
Grazer‐induced chain length plasticity reduces grazing risk in a marine diatom
We show that Skeletonema marinoi suppresses chain formation in response to copepod cues. The presence of three different copepod species (Acartia tonsa, Centropages hamatus, or Temora longicornis) significantly reduced chain length. Furthermore, chain length was significantly reduced when S. marinoi was exposed to chemical cues from caged A. tonsa without physical contact with the responding cells. The reductions in chain length significantly reduced copepod grazing; grazing rates on chains (four cells or more) were several times higher compared to that of single cells. This suggests that chain length plasticity is a means for S. marinoi to reduce copepod grazing. In contrast, chain length was not suppressed in cultures exposed to the microzooplankton grazer Gyrodinium dominans. Size‐selective predation may have played a key role in the evolution of chain formation and chain length plasticity in diatoms.
- 16 January 2012
- Published by Wiley in Limnology and Oceanography
- Vol. 57 (1) , 318-324
Grazer‐induced chain length plasticity reduces grazing risk in a marine diatom
We show that Skeletonema marinoi suppresses chain formation in response to copepod cues. The presence of three different copepod species (Acartia tonsa, Centropages hamatus, or Temora longicornis) significantly reduced chain length. Furthermore, chain length was significantly reduced when S. marinoi was exposed to chemical cues from caged A. tonsa without physical contact with the responding cells. The reductions in chain length significantly reduced copepod grazing; grazing rates on chains (four cells or more) were several times higher compared to that of single cells. This suggests that chain length plasticity is a means for S. marinoi to reduce copepod grazing. In contrast, chain length was not suppressed in cultures exposed to the microzooplankton grazer Gyrodinium dominans. Size‐selective predation may have played a key role in the evolution of chain formation and chain length plasticity in diatoms.