| 摘要: |
| 采用改变离体条件下大黄鱼消化道不同器官消化酶的作用温度和pH的方法,对其不同消化器官中的蛋白酶和淀粉酶活力进行测定,研究两种消化酶活力的分布特征以及温度、pH对两种消化酶活力的影响。结果表明,在消化道生理酸碱条件下蛋白酶活力胃>后肠>前肠>肝胰脏(P<0.01);淀粉酶活力肝胰脏、胃>后肠>前肠(P<0.01);在实验设定的条件范围内,胃、肝胰脏、前肠、后肠各部位蛋白酶的最适温度分别为35℃、30℃、40℃、35℃,淀粉酶的最适温度分别为30℃、25℃、30℃、35℃。随着温度由低向高变化,两种酶各部位活力均有从低向高然后逐渐降低的变化趋势;蛋白酶的最适pH值分别为2.2、6.0、7.0、8.0,淀粉酶各部位最适pH值分别为3.9、7.0、7.0、7.0。在设定的实验pH范围内,胃蛋白酶的活力随着pH值的升高而迅速降低,其余各部位酶均有随pH升高酶活力先升而后降的变化趋势。 |
| 关键词: 大黄鱼 蛋白酶 淀粉酶 温度 pH |
| DOI： |
| 分类号: |
| 基金项目:国家高技术研究发展计划(“863”)项目,2004AA623010、2004AA001180号 |
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| ACTIVITY AND DISTRIBUTION OF TWO ENZYMES IN DIFFERENT PARTS OF DIGESTIVE TRACT OF PSEUDOSCIAENA CROCEA: TEMPERATURE AND pH IMPACTS |
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ZHU Ai-Yi, CHU Xue-Lin
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Marine Science and Technology School,Zhejiang Ocean University,Zhoushan,316004
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| Abstract: |
| 20 farmed 1-yr-old Pseudosciaena crocea were sampled in a local fishery for the study on temperature- pH-related enzyme activity in the fish’s digestive system. The fish in group of 5, were fed with assorted feedstuff at first, starved for 24 hours, and then anatomize in a tray on ice. The stomach, intestine, foregut, and hepatopancreas were taken out for experimentation with fat and connective tissue removed. After these organmaterials were ground, homogenized and centrifuged, the activities of proteinase and amylase of P. crocea peptics were measured under different temperatures and pHs to determine the distribution of two digestive enzymes in digestive organs. The result showed that in physiological pH condition, the proteinase activity in the different organs was in the order of stomach> epigaster> foregut> hepatopancreas, while the amylase activity was hepatopancreas > stomach > epigaster > foregut. The optimal temperature for proteinase activity in stomach, hepatopancreas, foregut and epigaster were 35°C, 30°C, 40°C, and 35°C, and were 30°C, 25°C, 30°C, 35°C for amylase, respectively. The activities of the enzymes increased sharply at lower temperature but decreased at higher temperatures under designed experiment conditions. In pH, the optimal value for enzyme activity of proteinase in stomach, hepatopancreas, foregut and epigaster were 2.2, 6.0, 7.0 and 8.0 respectively and were 3.9, 7.0, 7.0 and 7.0 for amylase. The activity of proteinase in stomach at different pH levels decreased constantly. This study shows that in aquaculture, we should consider not only the assimilation of protein, but also that of saccharide. Therefore, adjusting the amount and proportion of amylase and protein according to environmental conditions to promote production and save cost. |
| Key words: Pseudosciaena crocea, Proteinase, Amylase, Temperature, pH |
