Method for extracting pullulan polysaccharide from high-viscosity fermentation broth

A method for extracting pullulan polysaccharide from high-viscosity fermentation broth includes following steps: (1) removing cells from the fermentation broth; (2) removing proteins; (3) decolorizing by macroporous resin adsorption; (4) removing ions by ultrafiltration; and (5) drying, crushing and packaging. In the extraction method of the present application, by using natural polymer bioflocculant chitosan, the high-viscosity fermentation broth can be processed without dilution and addition of filter aids and organic solvents for alcohol precipitation, which reduces the pressure of subsequent decolorization, properly recycles the cell proteins, and avoids the potential hazard of the organic solvents. The method can obtain high-purity pullulan polysaccharide, improving the product yield and quality, reducing solid waste, reducing the production cost, and achieving a safe, efficient, continuous and automated production process.