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

Abstract

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 identified 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 significantly, 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-3β-ol, which represented ≈ 41–49% of the free sterol fraction, with a volumetric concentration of ≈ 320 µg L1. Finally, pigment production under LTS was ≈ 700 µg L− 1. These results open the way for further progress towards the commercial and profitable production of P. gyrans for food and aquaculture applications.