Isolation and Characterization of Exopolysaccharides From Yeast Isolates

Exopolysaccharides (EPS) are high molecular weight polymers which are long chain composed of sugar residues and secreted by microbes into the surrounding environment. Sugar compositions of exopolysaccharides are dependent to culture medium composition and different physical conditions. Bacteria and fungi are most common EPS producers. In this study, we aimed to isolate the yeasts from different sources for maximum EPS production using optimized conditions. Yeast isolates PS1 and PS2 were analyzed for maximum EPS production on modified EPS media and optimized physical conditions such as carbon source, temperature and incubation duration. The maximum EPS (0.2 g/L) production was noted in PS1 and PS2. Characterization of purified EPS was done by HPLC, FT-IR and viscometer. PS1 (0.33mg/ml) and PS2 (0.28 mg/ml) showed increased carbohydrate content andsimilarly protein content also quantified for PS1(0.29μg/ml) and PS2 (0.180μg/ml) which indicates glycoprotein quantity on EPS. PS1showed 3% viscosity than PS2. We demonstrate the biological activities of purified EPS viz. Surfactant activity, flocculant activity and antioxidant activities. All these activities are observed in PS1; in case of PS2 it is not observed. In conclusion, yeast (PS1) exopolysaccharideshas a potential role in the textile, pharmaceutical and cosmetics industries.