Digestive Enzyme distribution in Adult Oplegnathus fasciatus and Effects of pH on the Enzymatic Activity

Digestive enzyme distribution in different adult fish and the effects of pH on their activities in striped beakperch Oplegnathus fasciatus were studied by means of enzyme analysis.Results indicated :1.the order of protease activities were stomachhindgutmidgutforegutliver,the amylase activities were foregutmidguthindgutstomachliver,and the lipase activities were foregutmidgutstomachhindgutliver,showing that the major site for protein digestion was stomach,and intestine played an important role in nutritional absorption while the effect was less in liver for the weak activities of enzymes.2.the optimum pH for protease and amylase were 3.2 and 5.6 in stomach,and activities of protease in stomach was higher in strong acid conditions,however the amylase activity was higher in weak acid conditions.The optimum pH for protease and amylase in liver were 7.6 separately and their highest activities were found in neutral conditions.The optimum pH for protease and amylase in intestine were 6.6 separately and the highest activities were detected in weak acid conditions.