Abstract
In succession to the previous reports on carbohydrases1) and proteases2), the tributyrin hydrolytic action of the extracts from the digestive organs was investigated in various growth stages of rainbow trout. And the following results were obtained.
(1) The hydrolytic action was recognized in the extracts from liver, pancreas, gall bladder and bile, intestine, pyloric caeca and stomach.-(Table 1)
(2) The hydrolytic activity of the extract increased in the early stages with the growth of the fish. The highest activity was found in the extract of the middle stage (body weight about 100g.), and after that the activity decreased gradually. The activity of the later stage (body weight about 1, 000g.) was considerably low.-(Table 2)
(3) The change of tributyrin hydrolytic activity with the growth was quite similar to that of the starch hydrolytic activity in all growth stages.
(4) Optimal temperatures of the esterases were relatively low (20°-25°C), and even at lower temperature (at 5°C) the esterases did not lose most of their activities.-(Fig. 2)
