*4.1. Cultivation Conditions*

*Crypthecodinium cohnii* CCMP 316 was obtained from the Provasoli-Guillard National Center for Marine Algae and Microbiota (NCMA) (USA). The culture inoculum was grown in a custom-made setup (see Scheme 3) consisting of 250 mL bottles with a working volume of 150 mL. The growth medium containing glucose 5 g·L−1, yeast extract 2 g·L−<sup>1</sup> and sea salts 25 g·L−1, with aeration 30 mL/min, rotation speed 130 rpm (provided by an orbital shaker PSU-20i, Biosan, Riga, Latvia) was maintained at 25 ◦C. The cultivation medium compositions for experiments are shown in Table 4, as well as in Tables 2 and 3. The initial optical density (OD470) of experiments was set to 0.15.

**Scheme 3.** *C. cohnii* cultivation experiment setup.


**Table 4.** The medium compositions for *C. cohnii* cultivations.

## *4.2. Dinoflagellate Extract and Extraction Ethanol Obtainment*

Dinoflagellate extracts (DEs) were obtained by recycling de-oiled *C. cohnii* biomass from the cultivation process in a laboratory scale bioreactor EDF-5.4\_1 (JSC Biotehniskais centrs, Riga, Latvia) by a method adapted from Gao et al. [45]. The de-oiled biomass was hydrolysed with H2SO4 at 121 ◦C for 20 min. The hydrolysed solution was neutralized with an appropriate amount of CaCO3. The solid fraction was separated from the hydrolysate by filtration. Most of the liquid hydrolysate was evaporated by heating at 120 ◦C, 600 rpm. The remaining moisture was evaporated by drying the sample in an oven at 80 ◦C overnight. The obtained dry extract pellets were grinned into a fine powder, hereinafter referred to as DE. De-oiled biomass for DEA obtainment was produced by a method adapted from Halim et al. [46]. Lipids were extracted from lyophilized biomass with the use of Soxhlet extraction with hexane as the solvent, containing 0.01% butylated hydroxytoluene (BHT). De-oiled biomass for DEB obtainment was produced by a method adapted from Mendes et al. [47]. Lipids were extracted with hexane (BHT concentration in hexane 0.01%) from the wet biomass, followed by incubation overnight at 20 ◦C with ethanol and KOH, simultaneously the extraction ethanol (EE) was obtained and separated. The acidification with HCl and additional hexane extractions were performed, the resulting suspension was used for DE obtainment as described above.

#### *4.3. Optical Density and Glucose Concentration Measurements*

*C. cohnii* growth was monitored via optical density (OD) measurements at a wavelength of 470 nm with a spectrophotometer Jenway 6300 (Cole-Parmer, Saint Neots, UK). The glucose concentration was measured enzymatically with an AccuChek ACTIVE blood sugar analyzer (Roche, Basel, Switzerland). Samples for OD and glucose measurements were taken on days 1, 2, 4, 7, 10, and 14. The experiments were performed in at-least triplicate and the experimental data was expressed as mean ± standard deviation (SD).
