Study on Activity and Stability of Proteases from Bacillus Sp. Produced by Submerged Fermentation

Objective: Investigations were carried out to isolate bacteria from salinealkali soils and determined optimized alkaline protease activity and stability produced by a wild strain of bacillus sp. in submerged fermentation (SMF). Methods: Optimum temperature for enzyme activity in the crude extract was 40 ◦C at a pH between 8.0 and 9.0. The studies on pH stability showed that the enzyme was stable in a range of pH 7.0–10.0 and the effect of the inhibitors showed it to be possibly an alkaline protease. Stability studies revealed temperatures around 40–60 ◦C. Results: The activity was reduced in the presence of Co2+, Fe2+ and Zn2+ ions, while the presence of K+ resulted in a discreet increase in proteolytic activity. The enzyme presented good stability towards organic solvents. Organic solvents such as 2ethyl1hexanol and oleyl alcohol enhanced the activity of enzyme. The enzyme presented good stability towards oxidizing agent. The crude enzyme preparation was compatible with commercial detergents, retaining their 50–60% activities. Conclusions: The results demonstrated the importance of submerged fermentation for the production of protease.