Thermo-alkali Stable Catalase from Bacillus sp.: Purification and Biochemical Characterization

Abstract

Thermo-alkali stable catalases are promising enzymes in biotechnological applications as H2O2-detoxifying 
systems. Catalase has been purified and characterized in this study from BACILLUS sp. The purification was 
performed with a three step procedure consisting of ammonium sulfate precipitation, ion exchange 
chromatography on DEAE- cellulose and gel filtration chromatography on Sephacryl-S-300 and finally achieved a 
16.6-fold-purifying over the crude extract with 50% overall yield. The purified catalase evidenced an estimated 
molecular weight of 65 kD. The enzyme also exhibited a broad optimal pH (6.0-10.0), and remained stable (100%) 
in alkaline pH (8.0-10.0),also it was most active at 70°C and stable within a range of 50-80°C. 2- mercaptoethanol, 
sodium azide, and potassium cyanide are known protein inhibitors, inhibited catalase activity by 70, 50 and 35% 
respectively.