Preparation method and application of deep-sea extracellular polymeric substances

The invention relates to a preparation method and application of deep sea extracellular polymeric substances. The preparation method comprises the following steps of: (1) inoculating a deep-sea bacterium SM-A87 stain to a liquid seed culture medium, carrying out shake culture for 2-3 days, then inoculating the stain to a fermentation culture medium for culturing for 20-30h, adjusting the fermentation temperature, and continuously culturing for 8-10 days to prepare a fermentation liquor; (2) adding absolute alcohol to the fermentation liquor for ethanol precipitation, separating to obtain a precipitate, washing the precipitate with absolute alcohol, and drying to obtain crude polysaccharide; (3) dissolving the crude polysaccharide into water, adding alkali protease for enzymolysis for 5-6h; and adding absolute alcohol for ethanol precipitation, separating to obtain a precipitate, washing the precipitate with absolute alcohol, and drying to prepare the deep-sea extracellular polymeric substances. The deep-sea extracellular polymeric substances prepared by the method have good moisture absorption and preservation properties and oxidation resistance and have a good application potential in the field of cosmetics.