Squalene is hypolipidemic by activation of PPARα via a ligand-mediated mechanism that regulates the expression of lipid metabolism genes in hepatocytes.

The objective of this study was to investigate the different fermentation conditions for Schizochytrium mangrovei TB17 biomass production rich in omega-3 and omega-6 fatty acids to determine the optimal conditions for bio-oil extraction from the algal biomass and to study the pharmacological effects of this bio-oil in experimental animal models. After 108 h of fed-batch fermentation, the cell density, dry biomass, lipid contents and docosahexaenoic acid (DHA) contents reached 392.53±3.89×106 cells/mL, 100.41±3.17 g/L, 41.04±0.87% dry cell weight (DCW) and 33.33±1.96% total fatty acids (TFAs) respectively. The in situ transesterification producing bio-oil rich in omega 3-6 fatty acids from the biomass of the TB17 strain reached a yield of TFAs of 45.02±1.37% DCW. The yields of PUFAs and SFAs were 30.02±0.38% and 69.98±0.53% of TFA respectively. The bio-oil mainly contains DHA and EPA accounting for 74.04±0.25% and 10.97±0.43% of the TFAs respectively. The bio-oil met the Vietnam food safety standard. According to the results of the acute in mice and the subchronic oral toxicity in rats for 90 days, the bio-oil rich in omega 3-6 fatty acids is safe and has the ability to improve memory and learning ability in mice which can be made functional food oil capsules for human.

Marine microalgae are an important source of raw materials for the extraction of highly bioactive substances for humans and domestic animals. In this study, the biological characteristics and the ability to grow biomass of green marine microalga of Dunaliella tertiolecta NY isolated from seawater of Namyit Island belonging to Spratly Islands, Vietnam (in May-June, 2021) was presented. Scientific name of the strain Dunaliella tertiolecta NY based on morphological characteristics and analysis of the sequence of rDNA ITS1-5.8S-ITS2 region was identified (with accession number of this gene region of this strain was supplied on the GenBank is OM 101011). At the best conditions for the growth (i.e. Walne medium, initial cell density of 2.0 x 106 cells/mL, growth temperature of 30oC, light intensity of 60 - 100 µmol/m2s, pH 7, salinity of 30-40‰), highest NY strain cell density of 8.63 x 106 cells/mL was obtained after 15 days of culture. The microalga D. tertiolecta NY was also successfully cultured on a pilot scale in the plastic bottles 10 L and closed photobioreactors 20 - 100 L resulting in a high biomass productivity of 285 mg/L/day and a biomass rich in polyunsaturated fatty acids such as gamma - linolenic acid (C18:3 ω-6; 5.07±0.59 % of total fatty acid - TFA), alpha - linolenic acid (ALA, C18:3 ω-3, 61.79±1.98 % of TFA) and stearidonic acid (SDA; C18: 4 ω-3, 1.59±0.65 % of TFA) qualified for the extraction of value bioactive compounds.

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