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、10¹¹cfu/g,每10d测定相关指标。40d投喂试验结束后,通过注射灿烂弧菌的方式对各组仿刺参进行攻毒试验。试验结果显示,105、1011cfu/g处理组与对照组相比,各指标差异不显著。而投喂含有10⁷ cfu/g和10⁹cfu/g地衣芽孢杆菌饲料时,仿刺参质量增加率、特定生长率、消化酶活性(胰蛋白酶、脂肪酶、淀粉酶)及免疫酶活性(酸性磷酸酶、碱性磷酸酶、超氧化物歧化酶、溶菌酶)均显著高于对照组。试验期间,淀粉酶及超氧化物歧化酶活性呈先升后降的趋势,其他指标呈上升趋势。攻毒试验表明,投喂107cfu/g和109cfu/g地衣芽孢杆菌的仿刺参累积死亡率较低,相对免疫保护率较高,仿刺参抵抗灿烂弧菌的能力得到提高。试验结果表明,当饲料中地衣芽孢杆菌密度为10⁷cfu/g和10⁹cfu/g时,仿刺参生长指标、消化酶活性和免疫酶活性均显著提高。

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.