Pavlova gyrans as a potential source of essential fatty acids, sterols and pigments: culture under low temperature

Abstract

Haptophytes are emerging as sustainable sources of high-value metabolites such as polyunsaturated fatty acids (PUFAs). The goal of this work was to isolate a native haptophyte from the southwestern Atlantic coast and to evaluate the effect of low-temperature stress on the production of PUFAs, sterols, and pigments during its cultivation. The strain was identi ed as Pavlova gyrans. Cultures were carried out in a photobioreactor for 10 days at 20°C (Control), lowering the culture temperature to 10°C at the beginning of the stationary growth phase (LTS). The lipid content of the biomass represented 13% of the dry weight, neutral lipids being the main lipid fraction. Under LTS, lipid production increased signi cantly, reaching a value of 305 mg L − 1 . The same effect was observed with PUFA content, which represented 41.3% of total fatty acids. The most abundant omega-3 (ω3) and omega-6 (ω6) fatty acids were eicosapentaenoic (EPA) and docosapentaenoic (DPA), respectively. PUFA production under LTS reached 13.5 mg L − 1 of which 7.41 mg L − 1 corresponded to ω3 and 6.09 mg L − 1 to ω6. EPA production was 5.93 mg L − 1 while DPA production was 3.03 mg L − 1 . The maximum production of phytosterols was obtained during the exponential growth phase. The most abundant phytosterol was 24-Ethylcholesta-5,22-dien-3βol, which represented ≈ 41-49% of the free sterol fraction, with a volumetric concentration of ≈ 320 µg L 1 . Finally, pigment production under LTS was ≈ 700 µg L − 1 . These results open the way for further progress towards the commercial and pro table production of P. gyrans for food and aquaculture applications. Key PointsP. gyrans is a robust strain suitable for biomass production in a photobioreactor.Low-temperature stress increased the production of EPA ω3 and DPA ω6 fatty acids.Phytosterols and pigments added value to the biomass.

The Composition and the Content of ∆-5 Sterols, Fatty Acids, and the Activity of Acyl-Lipid Desaturases in the Shoots of Ephedra monosperma, Introduced in the Botanical Garden of the Cryolithozone of Yakutia

“…In the microalgae Pavlova gyrans, a native haptophyte from the southwestern coast of the Atlantic Ocean, it was shown that the highest percentage of bound sterols was found at the early stages of its cultivation (on the 2nd day). However, by the end of cultivation (the 9th day), under the influence of low-temperature stress, the proportion of free sterols increased significantly [31]. The properties of plant cell membranes, including those under low-temperature stress, are affected by changes in the ratio between campesterol, stigmasterine, and β-sitosterol [32].…”