Improving the biological properties of Fomes fomentarius MG835861 exopolysaccharide by bioincorporating selenium into its structure

Research progress on production and biomedical applications of Schizophyllan as a tailor-made polysaccharide: A review

Schizophyllan (SPG) is a polysaccharide of Schizophyllum commune with a β-(1 → 3)-glucan backbone structure, which has been discussed in recent years for its extensive biomedical applications. Among the biological properties of this polysaccharide are anti-cancer, antioxidant, anti-inflammatory and strengthening of the immune system. Its unique triple helix structure offers various advantages as a carrier for genes or other biomolecules. The side chains of SPG can be effectively modified to change its neutral state and produce aldehyde or carboxylate groups. This review provides a detailed evaluation of the methods of production, extraction, structure and applications of schizophyllan. First, the methods of production in solid and submerged culture of this polysaccharide and its extraction with different solvents will be investigated. Then the structure of this polysaccharide, its unique structural features, including triple helix conformation, complex formation gelation behavior will be investigated. Various modifications of this polysaccharide will be described and finally, the biomedical applications of this polysaccharide will be discussed as a therapeutic agent, the use of which can be a new path in treatment and a solution to existing challenges.

Improvement of antibacterial activity of polysaccharides via chemical modification: A review

Antibiotic residue and bacterial resistance induced by antibiotic abuse have seriously threatened food safety and human healthiness. Thus, the development and application of safe, high-efficiency, and environmentally friendly antibiotic alternatives are urgently necessary. Apart from antitumor, antivirus, anti-inflammatory, gut microbiota regulation, immunity improvement, and growth promotion activities, polysaccharides also have antibacterial activity, but such activity is relatively low, which cannot satisfy the requirements of food preservation, clinical sterilization, livestock feeding, and agricultural cultivation. Chemical modification not only provides polysaccharides with better antibacterial activity, but also promotes easy operation and large-scale production. Herein, the enhancement of the antibacterial activity of polysaccharides via acetylation, sulfation, phosphorylation, carboxymethylation, selenation, amination, acid graft, and other chemical modifications is reviewed. Meanwhile, a new trend on the application of loading chemically modified polysaccharides into nanostructures is discussed. Furthermore, possible limitations and future recommendations for the development and application of chemically modified polysaccharides with better antibacterial activity are suggested.

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

The fermentation medium of a newly identified Cordyceps cicadae S1 was optimized by response surface methodology, with the optimal medium containing sucrose (80 g/L), yeast powder (60 g/L), KH₂PO₄ (5 g/L), MgSO₄·7H₂O (1 g/L) and Na₂SeO₃ (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 Cordyceps cicadae, purified and identified as a homofructose polysaccharide with a low average molecular weight of 9.95 × 10³ Da. The fine structure of PACI-1 was analyzed using NMR, CD, and AFM. Additionally, the in vitro 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 C. cicadae, which showed good antioxidant activity.