DENDROBIUM OFFICINALE ENDOPHYTIC FUNGUS STRAIN AND EXTRACELLULAR POLYSACCHARIDE PRODUCED THEREBY, AND EXTRACTION METHOD AND APPLICATION OF EXTRACELLULAR POLYSACCHARIDE

摘要

The present invention provides a Dendrobium officinale (D. officinale) endophytic fungus strain and an extracellular polysaccharide produced thereby as well as an extraction method and application of the extracellular polysaccharide. The extraction process of the extracellular polysaccharide includes: activating a strain; culturing seed liquid; fermenting and culturing; filtering the fermented liquid under vacuum; concentrated the filtrate under vacuum; conducting alcohol precipitation on the concentrated liquid; precipitating and centrifuging; dialyzing after dissolving the precipitates in water; freezing and drying the dialysate under vacuum; and obtaining the extracellular polysaccharide. The D. officinale endophytic fungus strain belongs to Fusarium solani, and the extracellular polysaccharide produced thereby has inhibitory effects on Escherichia coli, Staphylococcus aureus, Salmonella ssp., and Bacillus subtilis.