Distribution and characteristics of endogenous digestive enzymes in the red-eared slider turtle, Trachemys scripta elegans

Distribution and properties of the main digestive enzymes including protease and amylase, from stomach, pancreas and the anterior, middle and posterior intestine of the adult red-eared slider turtle Trachemys scripta elegans were studied at various pHs and temperatures. The optimum temperature and pH for protease in stomach, pancreas and the anterior, middle and posterior intestine were 40 °C, 2.5; 50 °C, 8.0; 50 °C, 7.0; 50 °C, 8.0; and 50 °C, 8.5; respectively. The optimum temperature and pH for amylase in stomach, pancreas and anterior, middle and posterior intestine were 40 °C, 8.0; 30 °C, 7.5; 40 °C, 7.0; 50 °C, 8.0; and 50 °C, 8.0; respectively. Under the optimum conditions, the order of protease activity from high to low was of pancreas, stomach and the anterior, posterior and middle intestine; the activity of amylase in descending order was of anterior intestine, pancreas, posterior intestine, middle intestine and stomach.