養殖烏魚消化道粗酵素液蛋白酶之特性和其對飼料蛋白質之體外消化能力

Characteristic of Proteases in Crude Extract from Digestive Tract of Cultured Grey Mullet (Mugil cephalus) and the in Vitro Digestibility on Feed Protein

陳翠瑤(Tusi-Yao Chen) ； 保愛貞(Ai-Chen Pao) ； 蘇崇文(Chung-Wen Su) ； 孫寶年(Bonnie Sun Pan)

《宜蘭大學生物資源學刊》 2卷1期 (2005/12) Pp. 57-64

https://doi.org/10.6175/job.2005.21.17

摘要

The purpose of this study was to evaluate the characteristic of proteases in crude extracte from the digestive tract of cultivated Grey Mullet. Besides, an in vitro proteolysis simulating digestion of six formulas with 32% protein, which consist of brown fish meal, white fish meal, soybean powder mixed meal or shrimp shell meal were also investigated. The result showed that there were two pepsins in the crude extract of stomach and their optimal pH is 2.0 and 3.5, respectively. The protease species from intestine tissue were trypsin, chymotrypsin, carboxypeptidase A, carboxypeptidase B and aminopeptidase when crude enzymes were evaluated with synthetic specific substrates. Chymotrypsin was the major digestive protease in intestine tract and the optimal pH is 7.5. In vitro protein digestibility showed the order: brown fish high content meal (BFHM)＞ white fish high content meal (WFHM)＞ white fish low content meal (WFLM)＞ soybean powder meal (SM)＞ white fish and soybean powder mixed meal (WFSM) ＞ soybean powder and shrimp shell mixed meal (SSM). The protein digestive efficiency was positively correlated to the total content of tyrosine and phenylalanine (r^2=0.746) in feeds except SSM.

關鍵字

蛋白酶 ； 消化率 ； 體外試驗 ； 烏魚

並列摘要

The purpose of this study was to evaluate the characteristic of proteases in crude extracte from the digestive tract of cultivated Grey Mullet. Besides, an in vitro proteolysis simulating digestion of six formulas with 32% protein, which consist of brown fish meal, white fish meal, soybean powder mixed meal or shrimp shell meal were also investigated. The result showed that there were two pepsins in the crude extract of stomach and their optimal pH is 2.0 and 3.5, respectively. The protease species from intestine tissue were trypsin, chymotrypsin, carboxypeptidase A, carboxypeptidase B and aminopeptidase when crude enzymes were evaluated with synthetic specific substrates. Chymotrypsin was the major digestive protease in intestine tract and the optimal pH is 7.5. In vitro protein digestibility showed the order: brown fish high content meal (BFHM)＞ white fish high content meal (WFHM)＞ white fish low content meal (WFLM)＞ soybean powder meal (SM)＞ white fish and soybean powder mixed meal (WFSM) ＞ soybean powder and shrimp shell mixed meal (SSM). The protein digestive efficiency was positively correlated to the total content of tyrosine and phenylalanine (r^2=0.746) in feeds except SSM.

並列關鍵字

protease ； digestibility ； in vitro ； mullet