Sophie Steinhagen1, Joackim Olsson2, Niklas Wahlström3, Annelous Oerbekke1 , Eva Albers2, Ulrica Edlund3, Ingrid Undeland4, Henrik Pavia1& Gunilla B. Toth1
Author affiliations:
1 Department of Marine Sciences-Tjärnö, University of Gothenburg, SE-452 96 Strömstad, Sweden
2 Department of Biology and Biological Engineering-Industrial Biotechnology, Chalmers University of Technology, SE-412 96, Göteborg, Sweden
3 Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44, Stockholm, Sweden
4 Department of Biology and Biological Engineering-Food and Nutrition Science, Chalmers University of Technology, Gothenburg, Sweden
Aquaculture of sea lettuces is continuously increasing. The high productivity, wide environmental tolerance, as well as the interesting functional and nutritional properties of Ulva biomass are accompanied by its multi-purpose-use in different industrial sectors. The focus of most studies has mainly been on the mature biomass, whereas there is only little knowledge on the ontogenetic development of gametes and spores which are crucial elements for a successful aquaculture.
With our study we investigated how changes in cultivation conditions (seeding density [500, 5000, 10000 swarmers ml-1], temperature [10, 15 °C], nutrients [PES, PESx3]) affect the hatchery behavior and thus the ontogenetic development of two different reproductive stages – gametes (male) and zoids – of Swedish Ulva fenestrata. To achieve this aim we conducted two consecutive, manipulative experiments in which we tested if the interactive effects of above named factors had an influence on 1) the early ontogenetic development of gametes and zoids and on 2) the biochemical composition of young thalli of U. fenestrata.
We were able to show that young gametophytes obtained from different parental material (sporophytes [zoids] and gametophytes [parthenogenetic developing gametes]) show differences in their ontogenetic development, growth rates and in their biochemical composition (total fatty acid, protein, amino acids, carbohydrate, pigments).
Together, we were able to show that the life stage affects the large-scale cultivability and/or biochemical composition of U. fenestrata. Furthermore, our study contributes to the optimization of hatchery cultivation conditions to facilitate a closed life cycle biomass production.