In Sweden, a PhD candidate demonstrated the potential of Nordic microalgae for simultaneous production of biomass and municipal sewage treatment in the Nordic climate. She has also studied how microalgae and bacteria work together and how this impacts the composition of microbial communities in open algae cultures.
Several Swedish microalgae strains that were able to grow in municipal wastewater were isolated and genetically classified. Eight strains were characterised on the laboratory scale as very effective in removing excess nutrients from wastewater; four showed signs of rapid growth, a high biomass production and lipid content; three of them also gave proof of effective adaptation to low temperatures or conditions with limited access to light.
In a pilot study, she used a DNA-based method called metabarcoding in order to investigate seasonal changes in an algae pond in Dåva (10 km from Umeå), which was inoculated in 2015 with a control strain of microalgae (i.e. not from our Nordic collection), which was allowed to grow from May to the beginning of November. The results indicated that the original microalgae was outcompeted by other algae and zooplankton, which caused a reduction in the biomass production and reduced the elimination of nitrogen and phosphorous, especially in the later part of the growing season.