2015 年 63 巻 4 号 p. 459-461
Dependency of pepsin activity on temperature and pH in the gastric juice (GJ) of farmed Pacific bluefin tuna Thunnus orientalis was determined in order to compare the enzyme properties of extracted and purified enzymes. Pepsin in fresh GJ had the highest activity at temperatures ranging from 25-30℃ and a pH value of 1.6; however, these temperature and pH values differed from those associated with both crude enzyme extracts and purified pepsin. The present study was the first to report the effects of pH and temperature on the activity of pepsin in the GJ of Pacific bluefin tuna.