Available online 10 December 2022

Nordic microalgae are a promising source of carotenoids and phenolic compounds

High light/cold (HL/C) stress can stimulate the production of bioactive compounds

The biomass production was not significantly affected by HL/C stress in the strains MC1 and B2-2

The production of bioactive compounds during HL/C stress was enhanced in MC1 and B2-2

No correlation was observed between the amount of bioactive compounds and the strain´s antioxidant property

Nordic microalgae are a group of photosynthetic organisms acclimated to growth at low temperature and in varying light conditions; the subarctic climate offers bright days with moderate temperatures during summer and cold and dark winter months. The robustness to these natural stress conditions makes the species interesting for large-scale cultivation in harsh environments and for the production of high-value compounds. The aim of this study was to explore the ability of nineteen species of Nordic microalgae to produce different bioactive compounds, such as carotenoids or polyphenols. The results showed that some of these strains are able to produce high amounts of carotenoids (over 12 mg·g-1 dry weight) and phenolic compounds (over 20 mg GAE·g-1 dry weight). Based on these profiles, six species were selected for cultivation under high light and cold stress (500 μmol·m-2·s-1 and 10 ˚C). The strains Chlorococcum sp. (MC1) and Scenedesmus sp. (B2-2) exhibited similar values of biomass productivity under standard or stress conditions, but produced higher concentrations of carotenoids (an increase of 40% and 25%, respectively), phenolic compounds (an increase of 40% and 30%, respectively), and showed higher antioxidant capacity (an increase of 15% and 20%, respectively) during stress. The results highlight the ability of these Nordic microalgae as outstanding producers of bioactive compounds, justifying their cultivation at large scale in Nordic environments.

gallic acid equivalent

1,1-diphenyl-2-picrylhydrazyl

total phenolic compounds

Carotenoids

Phenolic compounds

DPPH

Cold stress

High light stress

High-value compounds

© 2022 The Authors. Published by Elsevier B.V.