Reverse micelles extraction of nattokinase from fermentation broth

Nattokinase is a new fibrinolytic enzyme, which cleaves directly cross-linked fibrin in vitro. As its name implies, it is produced in the natto fermentation process. In this study, the purification of nattokinase from fermentation broth with AOT/isooctane micellar solution as the extractant was studied. Many factors, including pH, surfactant concentration, addition of isopropanol and contact time, were examined. By using the reversed micelles of AOT/isooctane to perform a full extraction cycle, it was found that about 80% of the total activity of nattokinase in the fermentation broth could be recovered and the purification factor was about 2.7. (C) 2004 Elsevier B.V. All rights reserved.