AUTHOR=Zhuansun Wanwan , Xu Jun , Liu Hengzhao , Zhao Ying , Chen Lulu , Shan Shufang , Song Shiqin , Zhang Haoyu , Dong Tingting , Zeng Huawei , Xu Qinxiang 

TITLE=Optimisation of the production of a selenium-enriched polysaccharide from Cordyceps cicadae S1 and its structure and antioxidant activity

JOURNAL=Frontiers in Nutrition

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.1032289

DOI=10.3389/fnut.2022.1032289

ISSN=2296-861X

ABSTRACT=<p>The fermentation medium of a newly identified <italic>Cordyceps cicadae S1</italic> was optimized by response surface methodology, with the optimal medium containing sucrose (80 g/L), yeast powder (60 g/L), KH<sub>2</sub>PO<sub>4</sub> (5 g/L), MgSO<sub>4</sub>·7H<sub>2</sub>O (1 g/L) and Na<sub>2</sub>SeO<sub>3</sub> (0. 1 g/L). Under these conditions, the extracellular polysaccharide yield was 8.09 g/L. A novel selenium-enriched polysaccharide (PACI-1) was isolated from <italic>Cordyceps cicadae</italic>, purified and identified as a homofructose polysaccharide with a low average molecular weight of 9.95 × 10<sup>3</sup> Da. The fine structure of PACI-1 was analyzed using NMR, CD, and AFM. Additionally, the <italic>in vitro</italic> antioxidant results showed that the PACI-1 had stronger antioxidant capacity than natural polysaccharides. These results provided a candidate strain for producing selenium polysaccharide and a new polysaccharide from <italic>C. cicadae</italic>, which showed good antioxidant activity.</p>