Partial characterization of pyloric-duodenal lipase of gilthead seabream (Sparus aurata).

In the present study, we report the isolation and characterization of seabream Sparus aurata pyloric caeca-duodenal lipase. Optimum activity was found at pH 8.5 and salinity of 50 mM NaCl. Lipase activity was sensitive to divalent ions, and extreme pH values (4, 5, and 12), being more stable at alkaline than acid pH. Optimum temperature was found at 50°C, but lipase was stable at temperatures below 40°C. Lipase has a bile salt sodium taurocholate requirement for increased activity. Gradient PAGE electrophoresis revealed the presence of four isoforms with apparent molecular masses of 34, 50, 68, and 84 KDa, respectively. Pyloric-duodenal lipase was able to hydrolyze emulsified alimentary oils. Results confirm the presence of true lipases in Sparus aurata digestive tract.