Purification and characterization of lipase from a new strain Staphylococcus argenteus MG2 (MTCC 12820)

Abstract

The lipase enzyme was isolated and purified from Staphylococcus argenteus MG2 (MTCC 12820) to homogeneity using ammonium sulphate precipitation followed by chromatographic techniques. This process resulted in a purification factor of 40.96-fold and a 26.25% recovery with a specific activity of 744.68 U mg-1. The molecular weight of the purified lipase was determined by SDS-PAGE to be 45 kDa. The Km and Vmax values of the purified lipase were calculated to be 4.95 mM and 79.36 µmol/min/mg-1, respectively. The maximum lipase activity was observed at pH 7.0 and 30 ºC with 100% stability, and it was also found to be stable in a broad range of pH (5-12) and temperature (30-90 ºC). The enzymatic activity of this Staphylococcal lipase was increased by Ca2+ to 105.71% at a concentration of 1 mM CaCl2. Additionally, it exhibited marked stability and activity in organic solvents. In the presence of 1% SDS surfactant, it retained 85.16% residual activity, while the metal chelator EDTA (inhibitor) reduced the lipase activity to 83.87% residual activity at a concentration of 1% w/v. This alkali-stable and thermo-stable lipase can be exploited by extending its use in the preparation of detergents and in various industrial and biotechnological applications.