| 摘要: |
| 采用双因子交互的方法研究了不同温度和pH值对南美白对虾淀粉酶、蛋白酶和脂肪酶活性的影响。结果表明，南美白对虾肝脏、肠道、胃的淀粉酶最适温度分别为30℃、35℃、30—35℃，最适pH均为6．2。肝脏、肠道、胃的蛋白酶最适温度分别为50—65℃、55—65℃、60℃，肝脏蛋白酶最适pH为8．5—9．0，肠道蛋白酶最适pH为7．5—8．5，胃蛋白酶最适pH为2．0和5．5—6．5。脂肪酶的活力很小，肝脏、肠道、胃的脂肪酶最适温度均为37℃ ，最适pH均为7．7。同时测得南美白对虾肠道、肝脏、胃组织内的pH分别为6．7—7．0、5．9—6．1、5．1—5．3。在三种消化酶各自最适的温度、pH值下，比较其活力大小，在肝脏、肠道、胃均为蛋白酶>淀粉酶>脂肪酶。 |
| 关键词: 南美白对虾, 温度, pH, 消化酶活性 |
| DOI： |
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| 基金项目:国家高新技术研究发展计划(863)资助项目，2001AA622060号 |
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| EFFECTS OF TEMPERATURE AND pH ON ACTIVITY OF DIGESTIVE ENZYMES IN SHRIMP PENAEUS VANNMEI |
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SHEN Wen-Ying1, HU Hong-Guo2, PAN Ya-Juan1
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1.Department of Biology，Shaoxing College of Arts and Sciences;2.Fishery Technology Development Station of Shaoxing County
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| Abstract: |
| Using temperature／pH two-factor cross method, activily of three digestive enzymes in liver, intestine and stomach of shrimp Penaeus vannmei with wet weight of(6.58±0.78)g were examined to find out the best temperature／pH environment. The resuhs showed that when pH value ranges was between 5.2— 8.7, the most favorable temperature for the amylase in liver. intestine and stomach were 30, 35 and 30— 35℃ respectively. When temperature range was between 15— 40℃, the most favorable pH values were all 6.2. The results indicated also that the amylase was conducive in weak acidic condition. The best temperatures in liver, intestine and stomach for the protease were 50— 65℃, 55— 65℃ and 60℃ respectively when the reacting pH values range was between 4.5— 9.0 in liver, intestine protease and 1.5— 6.5 in stomach protease, The best pH values for the protease of liver were 8.5— 9.0, and of intestine were 7.5— 8.5. and of stomach were 2.0 and 5.0— 6.5 when the reacting temperature range was 25—65℃ . These results indicated that the most favorable temperatures in liver, intestine and stomach for protease were higher than growth temperature of P.vannmei Furthermore, the protease in liver and intestine were conducive to alkaline condition while the protease in stomach was conducive to acidic condition. The activny of lipase was weak and lower than that of protease and amylase. The oplimum temperature in liver, intestine and stomach for the lipase all were 37℃ when the reacting pH values range was between 5.7— 8.2, and the optimum pH values all were 7.7 when the reacting temperature range was between 25— 45℃ . The result indicated that the lipase was conductive to weak alkalinity. The pH values in intestine, liver and stomach of P.vannmei measured in our experiment were 5.9— 6.1(6.08±0.O4), 6.7—7.0(6.82±0.O4)and 5.1—5.3(5.22±0.O4)respectively. This result indicated that the pH Values in digestive organs of P.vannmei were weak acidic. All the activity of three digestive enlzymes was in an order of from strong to weak: protease, amylase, lipase in liver, intestine and stomach at the most favorable reacting temperature and pH. |
| Key words: Penaeus vannmei, Temperature, pH, Activity of digestive enzymes |
