The response surface optimization of exopolysaccharide produced by Saccharomyces cerevisiae Y3 and its partial characterization

Abstract

Response surface methodology (RSM) was used to optimize the conditions of exopolysaccharides (EPSs) by Saccharomyces cerevisiae Y3. The results indicated that the yield of EPS reached 4.52 ± 0.14 g/L with 10.30% (w/v) sucrose, 0.64% (w/v) yeast extract, liquid volume 141.5 mL, which was 2.40 times the original EPS yield. Y3 EPS contained 83.65 ± 0.16% of total sugars, 15.27 ± 0.26% of uronic acid, 0.78 ± 0.02% of protein and 0.30 ± 0.12% of sulfuric acid groups. Y3 EPS maintained a relatively low viscosity, with intrinsic viscosities of 306.58 mL/g (25 °C) and 200.91 mL/g (35 °C), respectively. The EPS had high water solubility index (WSI), high water holding capacity (WHC) and good emulsifying ability (EA). Meanwhile, the EPS could absorb metal ions such as Cu²⁺, Fe²⁺ and Zn²⁺. In addition, Y3 EPS exhibited good antioxidant properties and coagulated skim milk with a concentration-dependent manner. These results indicated that S. cerevisiae Y3 EPS had applicable prospects in medicine, food, especially the dairy industry.

Keywords:

• Antioxidant activity
• exopolysaccharides
• physicochemical properties
• response surface methodology
• Saccharomyces cerevisiae

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China [32072189 and 32071519], Postdoc-toral Science Research Project of Heilongjiang Province, China [LBH-Q18105], Basic Scientific Research Operating Expenses of Universities in Heilongjiang Province, China (Science and technology innovation special project) [KJCX201921] and Project of Guangxi Key Laboratory for Polysaccharide Materials and Modifications, China [GXPSMM20-2].