Lipase from liver of seabass (Lates calcarifer): Characteristics and the use for defatting of fish skin

Lipase from liver of seabass (Lates calcarifer), with a molecular weight of 60 kDa, was purified to homogeneity using ammonium sulfate precipitation and a series of chromatographies, including diethylaminoethyl sepharose (DEAE) and Sephadex G-75 size exclusion columns. The optimal pH and temperature were 8.0 and 50 degrees C, respectively. Purified lipase had Michaelis-Menten constant (K-m) and catalytic constant (k(cat)) of 0.30 mM and 2.16 s(-1), respectively, when p-nitrophenyl palmitate (p-NPP) was used as the substrate. When seabass skin was treated with crude lipase from seabass liver at various levels (0.15 and 0.30 units/g dry skin) for 1-3 h at 30 degrees C, the skin treated with lipase at 0.30 units/g dry skin for 3 h had the highest lipid removal (84.57%) with lower lipid distribution in skin. Efficacy in defatting was higher than when isopropanol was used. Thus, lipase from liver of seabass could be used to remove fat in fish skin.