Departamento de Biologia, Faculdade de Ciências da, Universidade do Porto, Porto, Portugal.
Fish Physiol Biochem. 2012 Jun;38(3):595-601. doi: 10.1007/s10695-011-9537-5. Epub 2011 Jul 5.
A study was carried out with gilthead sea bream juveniles to assess the effect of water temperature (18 and 25°C) and dietary pregelatinized starch level (10, 20 and 30%) on digestibility of protein and starch and on the activity of proteolytic and amylolytic enzymes. ADC of pregelatinized starch was very high (>99%) irrespectively of dietary inclusion level, and it was not affected by water temperature. ADC of protein was also high (>90%) but improved at the higher water temperature. Dietary starch interacted with protein digestibility, which decreased as dietary starch level increased. Temperature affected both acid and basic protease activities, with acid protease activity being higher at 25°C and basic protease activity being higher at 18°C. However, total proteolytic activity and amylase activities were not affected by water temperature. Dietary carbohydrate exerted no effect on proteolytic or amylolitic activities. It is concluded that gilthead sea bream juveniles digest pregelatinized starch very efficiently irrespective of water temperature, due to adjustments of amylase activity to cope with temperature differences. Pregelatinized starch interacts negatively with protein digestibility, with the ADC of protein decreasing as dietary starch levels increase.
一项研究以斜带石斑鱼幼鱼为对象，评估了水温（18 和 25°C）和预糊化淀粉水平（10、20 和 30%）对蛋白质和淀粉消化率以及蛋白水解酶和淀粉水解酶活性的影响。预糊化淀粉的 ADC 非常高（>99%），与饮食中的添加水平无关，且不受水温影响。蛋白质的 ADC 也很高（>90%），但在较高水温下有所提高。饮食中的淀粉与蛋白质消化率相互作用，随着饮食中淀粉水平的增加而降低。温度影响酸性和碱性蛋白酶的活性，25°C 时酸性蛋白酶活性较高，18°C 时碱性蛋白酶活性较高。然而，总蛋白水解酶活性和淀粉酶活性不受水温影响。碳水化合物对蛋白水解或淀粉水解活性没有影响。综上所述，斜带石斑鱼幼鱼无论水温如何，都能非常有效地消化预糊化淀粉，这是由于淀粉酶活性的调整以适应温度差异。预糊化淀粉与蛋白质消化率呈负相关，随着饮食中淀粉水平的增加，蛋白质的 ADC 降低。
