日本蟳消化酶的初步研究

采用酶学分析方法研究了温度、pH对日本蟳Charybdis japonica中肠腺4种主要消化酶（蛋白酶、淀粉酶、纤维素酶和脂肪酶）活性的影响及4种消化酶在中肠腺、胃、肠中的活性分布。结果表明：蛋白酶、淀粉酶、纤维素酶、脂肪酶的最适温度分别为55、35、65、45℃,最适pH分别为6.2、5.5、4.4、7.5;在最适温度及最适pH试验条件下,中肠腺中的蛋白酶、纤维素酶和脂肪酶活性均为最高;蛋白酶活性的大小依次为中肠腺〉胃〉肠,纤维素酶和脂肪酶活性的大小依次为中肠腺〉肠〉胃,而淀粉酶活性在中肠腺、胃、肠中差别不大。

Digestive enzyme activities in crab Charybdis japonica

The effects of temperature and pH on the activities of protease,amylase, cellulase and lipase in the mid-gut gland and the distribution of the digestive enzymes in different parts of the digestive organs of crab Charybdis ja-ponica were studied by the enzymatic analytical method. The optimal temperatures were found at 55℃ for protease, 35℃ for amylase ,65℃ for cellulase and 45℃, for lipase. The optimal pH values were observed at 6.2 for prote-ase, 5.5 for amylase,4. 4 for cellulase,and 7.5 for lipase. Under the optimum conditions, the protease,cellulase and lipase had higher activity in the midgut gland than that in the stomach and intestine, the midgut gland being the most important organ for secretion of the digestive enzymes. The activity of protease in different digestive organs was in the descentant order arranged as midgut gland > stomach > intestine, the activities of ceUulase and lipase as mid-gut gland > intestine > stomach. Amylase had the similar activity as that in the midgut gland, stomach and intestine.