Evaluation of the biotechnological potential of a novel purified protease BS1 from Bacillus safensis S406 on the chitin extraction and detergent formulation

- Novel protease from Bacillus safensis S406 was purified (SB1) and characterized.
- BS1 with a molecular mass of 29 kDa.
- Optimum pH and temperature values for activity were pH 10 and 60 °C, respectively.
- BS1 is a potential candidate for peptide synthesis and detergent formulations.
- BS1 was found to be effective in the deproteinization of shrimp waste.

An extracellular alkaline stable protease BS1 from a new bacteria strain, Bacillus safensis S406, isolated from the Sfax solar saltern, was purified and characterized. The enzyme was purified to homogeneity by ammonium sulfate precipitation, Sephadex G-75 gel filtration, Mono-Q anion-exchange chromatography and ultrafiltration, with a 12.70-fold increase in specific activity and 20.29% recovery. The enzyme has a molecular weight of 29 kDa and appeared as a single band on native-PAGE. The optimum pH and temperature values of its proteolytic activity were pH 11.0 and 60 °C, respectively. BS1 was tested for the deproteinization of shrimp wastes to extract chitin. An enzyme-protein ratio of 10 U/mg of proteins allows to eliminate 93% of protein linked to the chitin after 3 h hydrolysis at 45 °C. Being very active in alkaline conditions, the potential application of BS1 in laundry formulation was investigated. The enzyme showed high stability in the presence of non-ionic surfactants and some commercial liquid and solid detergents, suggesting its eventual use in detergent formulations.