外源硒对仿刺参(Apostichopus japonicus)重要生理相关酶活性及体内硒含量的影响

在水温为16-18℃时,将平均体重为(60.75±0.32)g的仿刺参(Apostichhopus japonicus)饲养在150 cm×120 cm×60 cm的水箱中,通过在基础饲料中添加富硒酵母,使7组饲料中硒的浓度分别为0、0.20、0.40、0.80、1.60、3.20和6.40 mg/kg,进行为期28 d的生长实验,并对其体壁、消化道、呼吸树、肌肉等不同组织消化酶活力、免疫酶活力进行测定,探讨不同水平的外源硒对仿刺参生长、相关酶及体内硒含量的影响,并用氢化物发生-原子荧光光谱法进行仿刺参体内硒含量分析.结果显示,添加适宜浓度的硒提高了仿刺参的成活率(最高达100％)、消化酶和免疫酶的活性,蛋白酶(35.13 U/mg prot)和淀粉酶(0.51 U/mg prot)的最高活性分别为对照组的2.45倍和2.07倍.硒浓度为0.80-1.60 mg/kg时,仿刺参各组中的超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、碱性磷酸酶(AKP)和酸性磷酸酶(ACP)活性最高,显著高于其他组;仿刺参各组中的硒含量均有不同程度的上升,有机硒的提高倍数大于无机硒,说明富集到体内的硒以有机硒为主.研究表明,硒浓度为0.80-1.60 mg/kg时,仿刺参的养殖效果最佳.本研究丰富了仿刺参的营养学内容,为仿刺参健康、高效、可持续养殖提供了一定的参考依据.

Effects of Dietary Selenium-Enriched Yeast Levels on Important Physiological Enzymes and Enrichment of Selenium in Sea Cucumber (Apostichopus japonicus)

Selenium is an important trace element to maintain the normal physiological function of an organism.It plays important roles in regulating the balance of redox environment and improving the immunity.Appropriate amount of exogenous selenium can enhance the immune function of aquatic animals,improve ability to resist disease,and rich selenium content in aquatic product.In current study,juvenile sea cucumber (Apostichopusjaponicus),with body weight of (60.75±0.32) g,were cultured in tanks of each 150 cm × 120 cm ×60 cm for 4 weeks with water temperature of 16-18℃.They were fed diets containing selenium-enriched yeast at the dose of 0,0.20 mg/kg,0.40 mg/kg,0.80 mg/kg,1.60 mg/kg,3.20 mg/kg and 6.40 mg/kg.Survival rate was determined and different enzyme activities were assayed in order to evaluate the influence of different levels of selenium inclusion on biological indices related to growth,digestion and immunity.Selenium enrichment was detected by hydride generation-atomic fluorescence spectrometry (HG-AFS) in sea cucumber.The results showed that the survival of sea cucumber (up to 100％) and activities of digestive and immune enzymes were improved by appropriate concentration of selenium supplementation with the maximum activities of protease (35.13 U/mg prot) and amylase (0.51 U/mg prot),2.45 and 2.07 times higher than the control group.The maximum activities of superoxide dismutase (SOD),glutathione peroxidase (GSH-Px),alkaline phosphatase (AKP) and acid phosphatase (ACP) were observed in the group fed the diet containing selenium concentration of 0.80-1.60 mg/kg diet,and they were significantly higher than those in the other groups.Furthermore,selenium contents in the sea cucumber tissues were increased at different levels.The organic selenium concentration was several times higher than inorganic selenium,indicating that enrichment of organic selenium is the main way into the body.In conclusion,the diet of selenium concentration from 0.80 mg/kg to 1.60 mg/kg fed in sea cucumber was the most appropriate amount.This study enriches the nutrition research of sea cucumber and provides a frame reference for sea cucumber's healthy,efficient and sustainable breeding.