Streptomyces and application thereof

The invention discloses a streptomyces sp. NK-49 and an application thereof; and the application is a method for fermenting, cultivating, separating and purifying Epsilon-polylysine. The method comprises the following steps: firstly, picking a ring of spores from streptomyces sp. NK-49 which is stored on a Beinart inclined plane, and inoculating the spores serving as seeds in a Gao 1th culture medium for activated culture within 20 to 36 h; inoculating 5 to 15 percent of seed liquid to a synthetic medium taking amylolysis sugar or amylolysis sugar and glycerol as a carbon source, and shaking a flask for fermentation and culture for 48 to 96 h; after fermentation, conducting 6000 to 10000 rpm centrifugation on the fermentation liquid to remove thallus, collecting supernate, regulating the pH of the supernate to 8 by utilizing 5M NaOH solution, and filtering to removing deposited hetero proteins; utilizing weak acid type cation exchange resin to adsorb and remove Epsilon-polylysine molecules from the supernate