A preliminary study on polysaccharide extraction, purification, and antioxidant properties of sugar-rich filamentous microalgae Tribonema minus

• Published in: Journal of applied phycology Vol. 34; no. 6; pp. 2755 - 2767
• Main Authors: Huo, Shuhao, Wang, Huiying, Chen, Jing, Hu, Xinjuan, Zan, Xinyi, Zhang, Cunsheng, Qian, Jingya, Zhu, Feifei, Ma, Haile, Elshobary, Mostafa
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.12.2022; Springer Nature B.V
• Subjects: 2,2-diphenyl-1-picrylhydrazyl; 7th Congress of the International Society for Applied Phycology (ISAP 2020-2021); Algae; antioxidant activity; Antioxidant properties; Antioxidants; Aquatic microorganisms; Arabinose; Biological activity; Biomass; Biomedical and Life Sciences; Carbohydrates; Carbon dioxide; drugs; Ecology; Ethanol; Food; Free radicals; Freshwater & Marine Ecology; Galactose; Glucose; Hydroxyl radicals; Life Sciences; Lipids; liquids; Mannans; Mannose; Microalgae; Phytoplankton; Plant Physiology; Plant Sciences; Polysaccharides; Raw materials; Rhamnose; Saccharides; Scavenging; Sugar; sulfates; temperature; Tribonema; Tribonema minus; Uronic acid; uronic acids; Water purification; xylose; Polysaccharides; Physicochemical property; Antioxidant activity; Xanthophyceae
• ISSN: 0921-8971; 1573-5176
• DOI: 10.1007/s10811-021-02630-w

The total polysaccharide content of the sugar-rich filamentous microalga  Tribonema minus (Xanthophyceae, Tribonematales) under 2% CO 2 was up to 50%. The optimal conditions for the extraction of polysaccharide by hot water extraction-ethanol deposition were as follows: A maximum polysaccharide yield of 27.25% was obtained under the optimized conditions of extraction temperature 80°C, extraction time of 2 h, pH 9, and liquid to raw material 0.5:1 mL mg −1 . The crude polysaccharides were mainly acidic polysaccharides containing sulfate groups and uronic acid, and the contents of which were 14.57% and 42.21 mg g −1 , respectively. The crude polysaccharide was mainly composed of rhamnose, arabinose, xylose, mannose, glucose, and galactose with a molar ratio of 0.31:0.26:0.40:0.42:1.00:0.47. In addition, the polysaccharide had a potential antioxidant activity in vitro. The scavenging effect and reducing power of polysaccharides increased with the increase of polysaccharide concentration. The scavenging effect was 56.11%, 75.6%, and 61.89% for 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH), superoxide, and hydroxyl radicals at a concentration of 2 mg L −1 , respectively. Hence, T. minus polysaccharides could be a source of natural antioxidants that might be used in foods or pharmaceuticals.