The structure and moisture retention of Tremella polysaccharide fermented from GCMCC5.39 (FTP) were evaluated. After UV, infrared spectrum analysis, HPAEC-PAD, HPSEC and 1 D NMR analysis, the composition of the purified FTP was determined. Purified components of fermented Tremella polysaccharide (FTPS) was made of galactose, mannose, glucose, galactosmine, glucosamine, and contain a large amount of hydroxyl, carbonyl and amino groups. FTPS was α -neutral pyranose without uronic acid. FTPS-1 and FTPS-2 were obtained after purification by DEAE-Sepharose Fast Flow Column. The molecular weights of FTPS-1 and FTPS-2 were 25 722 and 177 263 Da. FTPS-2 had a better ability to prevent moisture loss, and the optimal moisture retention period was 0–4 h. FTPS-2 could significantly increase the moisture content of the skin epidermis and showed a dose-concentration relationship. The effect of FTPS-2 on the expression of different moisturizing genes was evaluated in a human skin keratinocyte model. The results showed that FTPS-2 has no cytotoxicity, and could significantly promote AQP3, TGM1, CASP14, HYAL2, FLG gene expression level in HaCaT cells. It has the most significant influence at HYAL2 protein expression on 50 μg/mL.

Tremella polysaccharide is known to be structurally unique and biologically active natural products, abundant and versatile in activities and applications in food industry, daily chemical industry and medicine industry. In order to improve the industrialisation of Tremella polysaccharide, the limitations of preparation and structure-activity relationship of Tremella polysaccharide were reviewed in this paper. The research progress of Tremella polysaccharide in the past 20 years was summarized from the sources, preparation methods, molecular structure, activity and application, and the research trend in the future was also prospected. The application prospect of Tremella polysaccharide in against multiple sub-health states was worth expecting.

The purpose of this study was to improve the yield of fermented Tremella polysaccharide (FTP) by optimizing the medium and to explore the effect of optimization on the structure. In this paper, the Plackett–Burman design and response surface method were used to optimize the fermentation medium of Tremella spore GT2# for FTP production. The results of the Plackett–Burman design showed that potato extract, glucose, and peptone were the main factors. The Box–Behnken experiment and regression analysis determined that the optimal concentrations of potato extract, glucose, and peptone were 22.01%, 29.38 g/L, and 2.61 g/L, respectively. After optimization, the fermentation period shortened from 5 days to 3 days, and the yield of FTP increased from 10.75 g/L to 12.50 g/L, which was in good agreement with the predicted value (12.36 g/L). Characterization of FTP obtained before and after optimization was carried out, and the results showed that medium optimization had significant effects on the primary structure of FTP, including molecular weight, monosaccharide composition, and proportion. After optimization, the content of acid polysaccharide increased, and the glycoside bonds changed from a-configuration to ß-configuration.