Method for preparing refined polysaccharide with bacteriostatic activity by utilizing cordyceps sinensis culture

The invention relates to the technical field of biology, in particular to a method for preparing refined polysaccharide with bacteriostatic activity by utilizing cordyceps sinensis culture and an application of the refined polysaccharide. According to the method, the cordyceps sinensis culture is used as a raw material, so that crude polysaccharide is extracted, and protein in the crude polysaccharide is removed by means of a macroporous resin adsorption method and a Sevag method, thereby preparing the refined polysaccharide; then stepwise alcohol precipitation is carried out to obtain the 95%ethanol alcohol precipitation cordyceps militaris refined polysaccharide CP95 with inhibitory activity on three gram-negative plant pathogenic bacteria. The preparation method has the characteristicsof simple operation, stable performance and low cost, and has important economic significance for better developing and utilizing the cordyceps culture and reducing the cleaning cost of the cordycepswaste culture medium. 本发明涉