Bacillus licheniformis SMIA-2 protease used as an additive in detergent formulations

Microbial proteases, especially from Bacillus spp., have been widely exploited for a broad variety of applications, such as the improvement of the cleaning efficiency of conventional detergents. In this work, the statistical design of the experiment was used to optimize the concentrations of a three-component mixture: Bacillus licheniformis SMIA-2 protease, Linear Alkylbenzene Sulphate and hydrogen peroxide, in an attempt to prepare an environmentally correct cleaning formulation. The results demonstrated that the combination of 1% (w/v) protease with 1.5% (w/v) LAS and 1% (w/v) H2O2 was effective in removing blood from cloth pieces and that a protease concentration decrease from 1.0% to 0.5% (w/v) would not have a significant impact on percent blood removal if LAS concentrations between 1.5-2.0% (w/v) in combination with lower (<0.5%, w/v) concentrations of H2O2 were used. Thus, the protease from Bacillus licheniformis SMIA-2 can be effectively incorporated into cleaning formulations together with LAS and hydrogen peroxide to formulate more sustainable detergents.