Purification and characterization of a harsh conditions-resistant protease from a new strain of Staphylococcus saprophyticus

Abstract

A major road block to the industrial usage of known proteases is their limited stability under harsh conditions. Hence, there is always a need for newer enzymes with novel properties that can further satisfy all industrial demands. This study described a benthic marine bacterium, Staphylococcus saprophyticus that secretes an alkaliphilic and broad-temperature active protease (10-80°C). The protease was successfully purified 42.66-fold using 70-80% ammonium sulfate precipitation and gel-permeable column chromatography. It had a relative molecular mass of 28 kDa on sodium dodecyl sulphatepolyacrylamide gel electrophoresis and retained high activity and significant stability at 60-80°C, over a wide range of pH (3.0-12.0), inhibitors and metal ions. Furthermore, the enzyme was stable in surfactants (such as sodium dodecyl sulfate), oxidizing agents (such as H₂O₂), bleaching agents (such as zeolite) and hydrophobic solvents (such as benzene, hexanes and hexadecane). These properties support the enzyme's potential as a vigorous biocatalyst for industrial applications.