Trial lecture: 'Why do microalgae produce toxins? - Costs and benefits of toxin production in marine microalgae'
Time and place: Jan. 17, 2024 10:15 AM, Nucleus, Bikuben, Kristine Bonnevies hus
Main research findings:
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Harmful algal blooms (HABs) are a global phenomenon in which harmful algal species proliferate, disrupting aquatic ecosystems and potentially threatening human health. In 1991 and 2019, blooms of the haptophyte Chrysochromulina leadbeateri caused massive fish-killing events along the coastline of Nordland and Troms in Northern Norway. The 2019 bloom was the largest recorded fish mortality event in Northern Europe linked to an algal bloom, with severe socio-economic consequences for local communities. Despite this, research on C. leadbeateri remains limited, partly because its fish-killing blooms are primarily known to form HABs in Northern Norway.
This thesis investigates the growth, toxicity and toxins produced by C. leadbeateri. High-throughput experiments were used to study its growth under different environmental conditions, while cell-based assays with epithelial gill cells were used to investigate the cytotoxicity of C. leadbeateri. A significant discovery was identifying a novel toxin group, named "leadbeaterins," through chemical separation and subsequent testing of fractions in cell-based assays. Interestingly, our analysis suggests that these toxins are structurally similar to those produced by fish-killing dinoflagellates. The findings provide new insights into the environmental conditions driving C. leadbeateri blooms and their ability to kill fish.
Adjudication committee
Prof. Per Juel Hansen, Department of Biology, University of Copenhagen
Ass. Prof. Elisabeth Varga, University of Veterinary Medicine, Vienna
Prof. Göran Erik Nilsson, Department of Biosciences, University of Oslo
Chair of defense
Prof. Josefin Titelman, Department of Biosciences, University of Oslo
Supervisors
Prof. Bente Edvardsen, Department of Biosciences, University of Oslo
Researcher Anita Solhaug, Toxinology Research Group, Norwegian Veterinary Institute
Senior Researcher Silvio Uhlig, Toxinology Research Group, Norwegian Veterinary Institute
Researcher Lada Ivanova, Toxinology Research Group, Norwegian Veterinary Institute
Prof. Tom Andersen, Department of Biosciences, University of Oslo