Purification, characterization and potential applications of a novel halotolerant metalloprotease from marine bacterium Vibrio sp. LA‐05

Abstract

AbstractBACKGROUNDMany reported proteases showed low activity and stability under harsh operating conditions, e.g. high pH, salinity and surfactants, which hinders expansion of their applications in industry. Here, a novel halotolerant metalloprotease from marine bacterium Vibrio sp. LA‐05 endowed with superior properties was purified and characterized, and its industrial application also evaluated.RESULTSThe protease was active and stable at 25–40°C and pH 6.0–10.0. Moreover, it was remarkably stable in high salt solution, tolerant to denaturing agents, organic solvents, surfactants and bleaching agents, and quite compatible and stable with many commercial detergents. Its residual activities were above 22% even after co‐incubation with 20% NaCl for 480 h. Except Ariel and Tide, the residual activities were all above 55% after co‐incubation with five other liquid detergents for 240 h. The corresponding theoretical analyses show that it is a metalloprotease containing 1 mol of zinc ion per mole of protease, the mature active protease predominantly in α‐helix form consists of 321 amino acids, and the central zinc ion along with 11 other conserved and crucial amino acid residues forms the catalytic domain.CONCLUSIONThese excellent properties indicated that the protease has considerable potential as a bio‐additive in the application of detergent formulations. © 2018 Society of Chemical Industry