苏云金芽孢杆菌对黄河鲤白细胞吞噬和溶菌酶活性的影响

为研究苏云金芽孢杆菌(Bacillus thuringiensisBt)对黄河鲤白细胞吞噬和溶菌酶活性的影响,将苏云金芽孢杆菌按1.0×1011、3.0×1011、5.0×1011cfu/kg 3个浓度添加在鱼用全价颗粒饲料中,投喂经嗜水气单胞菌(Aeromonas hydrophila)疫苗免疫的A1、A2、A3组和未免疫的B1、B2、B3组黄河鲤鱼,分别于试验的第1、15、30、40天时检测各组鲤鱼白细胞吞噬活性和血清溶菌酶活性。结果表明,添加苏云金芽孢杆菌可显著提高黄河鲤血液中白细胞吞噬活性和血清溶菌酶活性(P<0.05),且添加浓度越高,血液白细胞吞噬活性和溶菌酶活性越强。免疫组与未免疫组白细胞吞噬活性差异不显著(P>0.05),溶菌酶活性差异显著(P<0.05)。在停止投喂后10d,白细胞吞噬活性、血清溶菌酶活性逐渐下降,但与停止投喂Bt前相比,差异不显著(P>0.05)。

Effects of Bacillus thuringiensis as Food Additive on the Phagocytic Activity of Leucocytes and Lysozyme Activity of Cyprinus carpio in the Yellow River

To study the effects of Bacillus thuringiensis(Bt) on the leucocyte and lysozyme activities of Cyprinus carpio in the Yellow River,the fishes of group A1,A2 and A3 immunized with A.hydrophila and the unimmunized fishes of group B1,B2,and B3 were feed with the forage added with Bt at the concentrations of 1.0×1011,3.0×1011 and 5.0×1011 cfu/kg,respectively.The phagocytic activities of leucocytes and lysozyme activities were determined at 1、15、30 and 40 days post-feeding.The results showed that all the different concentrations of Bacillus thuringiensis enhanced the phagocytic activities of leukocytes and lysozyme activities of Cyprinus carpio in the Yellow River(P<0.05),but high dose groups showed higher effects than that of low dose groups.No obvious different phagocytic activities of leukocytes were observed among the immunized and unimmunized groups(P>0.05),but the lysozyme activities were significantly different(P<0.05).The phagocytic activities of leucocytes and lysozyme activities declined at 10d after the stopping of feeding mixed diet,but no significant differences were observed compared to that of feeding mixed diet(P>0.05).