Development of cell wall model of Escherichia coli for periplasmic protein release and purification of interferon-α2b using aqueous two-phase system

Osmotic shock is the most reliable method for periplasmic protein recovery. Osmotic shock relies on the intactness of cell wall which is modified by the changes in fermentation conditions. Fermentation conditions alter the cell wall property which in turn affects osmotic shock for periplasmic protein release. Osmotic shock uses large amount of sucrose yet, recycling option has not been considered. In order to address these issues, this study linked the changes in fermentation conditions with the periplasmic protein release. Sucrose from osmotic shock was reused to purify the recovered proteins and hence this served as a sustainable downstream process.