Exopolysaccharides from the Energy Microalga Strain Botryococcus braunii: Purification, Characterization, and Antioxidant Activity

Abstract

Botryococcus braunii, a prestigious energy microalga, has recently received widespread attention because it can secrete large amounts of exopolysaccharides (EPS) with potential applications in food, cosmetics, and nutraceuticals. Unfortunately, the insufficiency of research on the bioactivity and structure–activity relationship of B. braunii EPS has impeded the downstream applications. In the present study, alcohol precipitation, deproteinization, and DEAE-cellulose column chromatography were used to extract and purify B. braunii SCS-1905 EPS. It was found that B. braunii SCS-1905 EPS were high-molecular-weight heteropolysaccharides containing uronic acid (7.43–8.83%), protein (2.30–4.04%), and sulfate groups (1.52–1.95%). Additionally, the EPS primarily comprised galactose (52.34–54.12%), glucose (34.60–35.53%), arabinose (9.41–10.32%), and minor amounts of fucose (1.80–1.99%), with the presence of a pyranose ring linked by a β-configurational glycosidic bond. Notably, the antioxidant activity of crude exopolysaccharides (CEPS) was stronger, and the half maximal inhibitory concentration (IC50) for ABTS and hydroxyl radicals was significantly lower than that of deproteinized exopolysaccharides (DEPS). Overall, this study indicated a potential application of B. braunii SCS-1905 EPS as a natural antioxidant. In summary, B. braunii EPS could be used as a potential feedstock for the production of antioxidant health foods.

Stimulating immunoglobulin response by intramuscular delivery of exopolysaccharides-adjuvanted mannheimiosis vaccine in goats

“…One milligram of extracted Tetraselmis chui EPS powder was extracted [ 9 , 19 ] and diluted in 100 mL of PBS to prepare a stock solution with a final concentration of 0.01 mg/mL. Then, only 50 μL of diluted EPS was combined with the pellet of 10 6 CFU/mL of formalin-killed MHA2 vaccine to make EPS-MHA2 vaccine [ 20 ].…”

“…Available at www.veterinaryworld.org/Vol.15/December-2022/25.pdf bronchioles. The disease can rapidly progress from mild to fatal [9]. Mannheimiosis remains a challenging problem in goats in Malaysia [10].…”

“…Mortality is due to the aggregation of fibrinous exudate and macrophages in the bronchioles. The disease can rapidly progress from mild to fatal [ 9 ]. Mannheimiosis remains a challenging problem in goats in Malaysia [ 10 ].…”

Microalgae Strain Porphyridium purpureum for Nutrient Reduction in Dairy Wastewaters

“…Due to their lack of toxicity, EPS are increasingly taken into account in food technology through their interesting functional properties, which can be exploited to impart attractive properties to foods [30]. Considering that the EPS that can be derived from Porphyridium purpureum microalgae contain polysaccharide sulphate which can provide antioxidant, antibacterial and antiviral properties they have great potential to be used, besides pharmaceutically, in the food industry; for example, as a natural preservative (assuring the storage stability of processed food products) or as a natural thickener [14,[31][32][33][34]. Considering that food processing also involves technological operations that take place at high temperatures, the thermal stability of EPS is a must.…”

Research Progresses on the Physiological and Pharmacological Benefits of Microalgae-Derived Biomolecules

“…To obtain EPS, B. braunii SCS-1905 was extracted and precipitated in ethanol, and then, it was deproteinated. After that, column chromatography using a DEAE-cellulose matrix was used to purify the EPS [ 21 ].…”