Enhanced α-glucosidase inhibition activity of exopolysaccharides fractions from mycelium of Inonotus obliquus under addition of birch sawdust lignocellulose component

The addition of lignocellulose in the submerged cultivation of Inonotus obliquus has been considered a feasible alternative to improvement the bioactivity of exopolysaccharides. To investigate the key components of lignocellulose in the synthesis of active polysaccharide by I. obliquus, cellulose and hemicellulose polysaccharides were isolated from birch sawdust and their effects on the production and activity of exopolysaccharides from I. obliquus were evaluated in the present study. Results showed that α-glucosidase inhibition rates of exopolysaccharides in two cellulose polysaccharide groups (C-36 and C-48) and water extracted hemicellulose polysaccharide group (H-0) were significantly increased by 3.44–4.09 times compared with control group. Three polysaccharides fractions (DPC36–1, DPC48–1 and DPH0–1) in above three groups were isolated from I. obliquus using DEAE-52 cellulose chromatography, which were composed of glucose with molecular weight distribution ranging from 13.94 kDa to 74.48 kDa. These results might stimulate the development of mycelium polysaccharides from I. oblqiuus as alternative anti-diabetes agents and provide important insights into the relationship of structure-bioactivity of fungal polysaccharides with cellulose and hemicellulose as carbon source donors.