| 摘要: |
| 本研究探讨饲料中添加地衣芽孢杆菌(Bacillus licheniformis)对大泷六线鱼(Hexagrammos otakii)生长、肠道消化酶、血清非特异性免疫及抗病力的影响。选取平均体重为(22.0±2.0) g的大泷六线鱼270尾，随机分成3组(对照组和2个不同菌剂水平的实验组)，每组3个平行，每个平行 30尾鱼。对照组投喂仅有蛋白液包裹的基础饲料，实验组投喂含活菌量达5×107 CFU/g(0.5%)和1×108 CFU/g(1.0%)地衣芽孢杆菌的实验饲料。投喂50 d后进行致病菌杀鲑气单胞菌(Aeromonas salraonicida)攻毒感染，测定14 d内累积死亡率。结果显示，实验组饲料中地衣芽孢杆菌可显著提高大泷六线鱼的特定生长率(SGR) (P<0.05)。与对照组比较，0.5%和1.0%地衣芽孢杆菌均可提高大泷六线鱼血清中SOD、CAT及T-AOC活性(P<0.05)，降低MDA含量(P<0.05)；GSH-Px活性在1.0%实验组较对照组下降，而0.5%实验组较对照组提高。地衣芽孢杆菌实验组鱼血清GS、MDH和HK活性均得到提高(P<0.05)，0.5%和1.0%不同剂量组的提高程度不同。地衣芽孢杆菌实验组鱼血清中AST和ALT活性较对照组均降低(P<0.05)，CHE和ADA活性较对照组有提高(P<0.05)。实验组鱼肠道胰蛋白酶、淀粉酶和脂肪酶活性均有不同程度的提高，且1.0%实验组活性最强(P<0.05)。攻毒实验结果显示，1.0%地衣芽孢杆菌组大泷六线鱼14 d内累积死亡率仅有35.55% (P<0.05)。由此可见，饲料中添加地衣芽孢杆菌可促进大泷六线鱼生长，提高其肠道消化酶活性及非特异性免疫酶活性，增强其对杀鲑气单胞菌的抵抗能力。 |
| 关键词: 地衣芽孢杆菌 大泷六线鱼 非特异性免疫 抗病力 |
| DOI：10.19663/j.issn2095-9869.20191111001 |
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| Effect of Bacillus licheniformis on growth, intestinal digestive enzymes, serum non-special immune and resistance against Aeromonas salraonicida in fat greenling, Hexagrammos otakii |
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FAN Ying, WANG Xiaolu, YU Xiaoqing, LIU Hongjun, YE Haibin, WANG Shuxian, DIAO Jing, HU Fawen, JIAN Yuxia
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Marine Biology Institute of Shandong Province, Shandong Key Laboratory of Disease Control in Mariculture, Qingdao 266104
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| Abstract: |
| The present study aimed to assess the effect of Bacillus licheniformis on the growth, intestinal digestive enzymes activity, non-specific immunity and resistance against Aeromonas salraonicida in the fat greenling (Hexagrammos otakii). A total of 270 H. otakii with an average initial body weight of (22.0±2.0) g/tail were randomly allocated to three groups (the control group and two experimental groups with different B. licheniformis levels) with three parallels per group and 30 fish per parallel. Fish in the control group were fed a basal diet consisting of albumen, and the ones in the two experimental groups were fed basal diets supplemented with 5×107 (0.5%) or 1×108 CFU/g (1.0%) B. licheniformis, respectively. After 50 days, fish were infected with A. salraonicida, and the cumulative mortality rate was determined within 14 days. The specific growth rate was found to be significantly higher in fish fed diets containing B. licheniformis when compared with the control group (P<0.05). Furthermore, the activities of SOD, CAT, and T-AOC in the serum of H. otakii in the experimental groups were significantly increased compared with the control group (P<0.05). Conversely, the MDA levels in the experimental groups were decreased compared with the control group (P<0.05). The GSH-Px activity in the 1.0% B. licheniformis group was lower than that in the control group, but the activity in the 0.5% B. licheniformis group was higher than that in the control group. The activities of GS, MDH, and HK in the serum of fish in the experimental groups were increased compared with the control group (P<0.05). Compared with the control group, AST and ALT activities in the serum of fish in the experimental groups were decreased (P<0.05) and CHE and ADA activities were higher than those in the control group (P<0.05). The activities of trypsin, amylase and lipase in the intestines of fish in the experimental groups were increased to different degrees, with the highest activity observed in the 1.0% B. licheniformis group (P<0.05). The bacterial challenge test revealed that the 14 day cumulative mortality rate in the 1.0% B. licheniformis group was only 35.55% (P<0.05). The results obtained in the present study revealed that B. licheniformis can increase growth, activities of intestinal digestive enzymes, and non-specific immunity, as well as enhance resistance against A. salraonicida in H. otakii. |
| Key words: Bacillus licheniformis Hexagrammos otakii Non-specific immunity Resistance |
