Neocystis mucosa, a polar alga producing oils containing polyunsaturated essential fatty acids

Abstract

The sustainable cultivation of microalgae for bioactive compounds, such as polyunsaturated fatty acids (PUFAs), is vital for addressing global health and nutritional challenges. However, the availability of algal strains suitable for year-round cultivation in temperate climates is limited. This study investigates the psychrotolerant green alga Neocystis mucosa (strain Šnokhousová and Elster, CCALA No. 1141), isolated from Svalbard soil, as a promising candidate for outdoor cultivation in Mid-European climates.

Molecular analysis confirmed the identification of the strain as N. mucosa. It demonstrated optimal growth at 12 °C under low light intensity (10 μmol·m⁻²·s⁻¹). However, it tolerates short-term light and temperature fluctuations (5 °C to 25 °C). This resilience ensures that there is no significant risk of cell death due to temperature and light variations, such as those that occur during sunny winter days. Nighttime LED lighting increased growth by 160 % compared to sunlight alone, yielding biomass production rates of 1.73 g·m⁻²·d⁻¹ and 0.135 g·L⁻¹·d⁻¹, with a maximum dry matter of 6.3 g·L⁻¹. The strain displayed high lipid productivity, with unsaturated fatty acids comprising 51–63 % of total fatty acid content. Notable components included linoleic acid (14.9–17.1 %), α-linolenic acid (18.3–23.1 %), and hexadecatetraenoic acid (10.2–16.7 %). Lipid and PUFA percentages increased with culture age.

This study highlights the practical potential of polar N. mucosa for year-round cultivation in temperate climates, offering a sustainable source of PUFAs for food supplementation and immunomodulation, including reducing risks associated with COVID-19. These findings advance biotechnological approaches to sustainable PUFA production, addressing global dietary needs.