Abstract:In order to obtain high purity nattokinase from the fermentative broth of Bacillus subtilis, some separation and purification techniques were explored. The optimized separation and purification process includes the following steps: first removing cells by centrifugation, then removing the impurity protein by 30% ammonium sulfate, precipitating the crude extracts of nattokinase by 65% ammonium sulfate and finally purifying the crude extracts by DEAE-Sepharose fast flow ion-exchange chromatography, CM-Sepharose fast flow ion exchange chromatography and Phenyl-Sepharose Fast Flow chromatography, respectively. Besides, the fibrinolytic activity of the nattokinase was measured by means of fibrin plate method. The purification factor and activity recovery of the nattokinase are 32.2% and 13.2%, respectively. The above-mentioned processes can serve as an efficient way to prepare pure nattokinase with high yield especially for lab scale.
