Cultivation and extraction of omega 3-6 fatty acids from the heterotrophic marine microalga Schizochytrium mangrovei TB17 to make a functional food

Abstract

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.

Characterization and Optimization of Culture Conditions for Aurantiochytrium sp. SC145 Isolated from Sand Cay (Son Ca) Island, Vietnam, and Antioxidative and Neuroprotective Activities of Its Polyunsaturated Fatty Acid Mixture

“…SC145 in the FAAE or FFA forms are not toxic to mice. Our findings are in line with reports by Falk et al [11] and Thom and Hong [15]; Falk et al [11] reported that DHA-rich oil from Schizochytrium sp. (DHA accounted for 41.37% of TFAs) at a dose of 5000 mg/kg/day was safe for embryos and fetuses and during the growth of mice, and Thom and Hong [15] reported that bio-oil rich in omega 3-6 fatty acids (DHA, EPA, and DPA) was safe and had the ability to improve memory and learning ability in mice.…”

“…Acute toxicity and LD 50 (50% lethal dose) values were evaluated as described by the guidelines of the World Health Organization [80] and the Organization for Economic Cooperation and Development (OECD) [81]. Ninety-six white Swiss mice (male and female, weights ranging from 18 to 22 g) were randomly divided into 12 groups with 8 mice per group and treated with PUFAs rich in omega 3-6 fatty acids in the form of FFA or FAAE at different dosages (3.82, 6.11, 8.40, 10.69, 12.98, and 15.35 g/kg body weight/day), as described previously [15]. Mortality or signs of morbidity in mice in each group were recorded over 72 h. Then, animals were continuously monitored until the end of the 7th day after the first oral administration.…”

“…All experimental and control groups were evaluated over 90 days. The hematological parameters, biochemical parameters, and liver and kidney functions of the rats were analyzed before (D0) and after oral administration for 45 days (D45) and 90 days (D90), as described by Thom and Hong [15].…”

“…Various methods can be used for the extraction and purification of PUFAs, such as the use of urea complexes, low-temperature solvent crystallization, fractional distillation, hydrolysis, enzymatic techniques, and high-pressure liquid chromatography (HPLC) [14,15]. Of the above methods, the use of urea complexes is the most suitable for attaining PUFArich samples [15].…”

Update of the list of QPS‐recommended biological agents intentionally added to food or feed as notified to EFSA 15: suitability of taxonomic units notified to EFSA until September 2021

“…Thom and Hong (2021) concluded that A. mangrovei TB17 bio‐oil met the Vietnamese food safety standard. According to the results of assessment of the acute toxicity in mice and the subchronic oral toxicity in rats for 90 days, the bio‐oil rich in omega 3–6 fatty acids is safe.…”