Purification and Characterization of an Extracellular Alkaline Solvent-stable Metalloprotease Secreted from Newly Isolated Bacillus sp. DEM05: Optimization of Protease Production

BACKGROUND: Proteases play an important role in food, leather, detergent, and medical technologies. OBJECTIVES: In the current study, an alkaliphilic solvent-stable thermotolerant metalloprotease was isolated from Bacillus sp. DEM05. MATERIAL AND METHODS: For culture optimization, carbon, and nitrogen sources as well as incubation temperature, pH, and time were examined. RESULTS: Herein the highest outcome for bacterial growth and protease production was obtained after 72 h incubation (pH 7) at 37 °C. DEM05 protease was successfully purified and the specific activity of the protease was 1075 U.mg(-1). The purity of the enzyme was verified by SDS-PAGE electrophoresis as a single band of 30 kDa. The optimal activity of the enzyme was at pH 10 and 50 °C. H(2)O(2), SDS, Triton X-100, Zn(2+), Co(2+), and Cu(2+) could increase the protease activity. EDTA inhibited the protease activity, revealed that it can be classified as a metalloprotease. The enzyme was compatible with the water-miscible and water-immiscible organic solvents and proteolyzed several substrates, implying the wide substrate specificity. CONCLUSIONS: The results brought convincing evidence that DEM05 protease could be recruited as a novel prevailing protease that can be earmarked on industrial and medical technologies.