地衣芽孢杆菌对仿刺参生长、消化和免疫功能的影响

为探讨益生菌制剂对仿刺参生长、消化和免疫功能的影响,选用分离自仿刺参肠道的地衣芽孢杆菌作为潜在的益生菌株进行仿刺参投喂试验.选择初始体质量为(7.17±0.86)g的仿刺参为试验对象,设计空白对照组及益生菌处理组进行投喂.益生菌在饲料中的添加密度分别为105、107、109、1011 cfu/g,每10 d测定相关指标...

Effects of Bacillus licheniformis on Growth,Digestive and Immune Functionsof Sea Cucumber Apostichopus japonicus

A feeding experiment was conducted to investigate the effects of probiotics on growth, digestive enzyme activity and immune defense factors of sea cucumber Apostichopus japonicus . The Bacillus licheniformi isolated from the intestines of sea cucumber was identified as the strain of potential probiotics. Sea cucumber with an initial body weight of (7.17±0.86) g was fed a control diet or a diet supplemented with probiotics containing B. licheniformis . The additive does of living Bacillus cell in feed were 10 5 , 10 7 , 10 9 , and 10 11 cfu/g and the relevant indices were determined every ten days. After 40 days of feeding with B. licheniformis -diets or control diet, live Vibrio splendidus was injected into the body wall of sea cucumber to conduct the challenge test. Results showed the sea cucumber fed diet with 10 5 and 10 11 cfu/g B. licheniformis had no significant difference growth, digestive enzyme activity and immune defense factors compared with the control. Added viable B. licheniformis with the concentration of 10 7 , 10 9 cfu/g into the feed not only promoted the weight gain rate(WGR) and specific growth rate(SGR), but also significantly improved the digestive enzyme activity, such as activities of trypsin(TRY), lipase(LPS) and amylase(AMS), besides the immune defense factors, activities of acid phosphatase(ACP), alkaline phosphatase(AKP), super-oxide dismutase(SOD) and lysozyme(LZM) were also increased significantly compared with the control. Most indices mentioned above were increased continually during the whole study other than the activities of AMS and SOD of sea cucumbers were increased initially and then decreased. The challenge test showed that sea cucumbers fed the diet either with 10 7 or 10 9 cfu/g B. licheniformis had lower cumulative mortality rate(CMR) and higher relative percent survival(RPS), and had a potential of enhancing the disease resistance against V. splendidus compared with controls. The findings indicated that when the supplemental level of B. licheniformis in diets at the doses of 10 7 and 10 9 cfu/g, the growth, digestion and immune function of sea cucumber were promoted effectively.