Nguyen_2023_Protein.Expr.Purif__106419

A lipase EstA from Bacillus subtilis KM-BS was expressed in Escherichia coli BL21 (DE3) cells. The recombinant enzyme achieved high activity (49.67 U/mL) with protein concentration of 1.29 mg/mL under optimal conditions at the large-scale expression of 6 h and post-induction time at 30 degreesC using 0.1 mM isopropyl-beta-d-thiogalactopyranoside (IPTG). The optimal temperature and pH of the purified enzyme were at 45-55 degreesC and pH 8.0 - 9.0, respectively. Activity of the purified enzyme was stable in the presence of 1 mM Ca(2+); stimulated by 1 mM Mg(2+) and Mn(2+), and inhibited by Fe(3+). A significant amount of fatty acids was released during the hydrolysis of waste cooking oil under the catalysis of purified lipase, indicating that this recombinant lipase showed promise as a suitable candidate in industrial fields, particularly in biodiesel and detergent sector.