Characterization of detergent compatible protease of a halophilic Bacillus sp. EMB9: Differential role of metal ions in stability and activity

► Purification of halophilic Bacillus sp. EMB9 protease to homogeneity. ► Remarkable stability of protease in organic solvents at high concentrations. ► Divalent Ca2+ maintains native structure and prevents unfolding of protease. ► Monovalent Na+/K+ cations regulate activity and refolding of dialysed enzyme. ► Application in the efficient removal of blood stain.