拟诺卡氏菌骨架对凡纳滨对虾生长及免疫功能的影响

将研究室分离纯化的卢森坦拟诺卡氏菌扩大培养,发酵液经过超声波破碎、离心、胰蛋白酶酶解、脱脂、冷冻干燥,得到白色细胞壁骨架。在基础饲料中添加0.1%和0.2%的拟诺卡氏菌细胞壁骨架,饲喂凡纳滨对虾幼虾体质量(4.21±1.28) g],养殖周期为4周,测定各处理组对虾体质量,统计各组存活率,使用南京建成试剂盒测定对虾血淋巴和肝胰腺组织中的一氧化氮合酶、超氧化物歧化酶、酚氧化酶、溶菌酶、谷胱甘肽过氧化物酶活性及丙二醛的含量,佛波豆蔻酸乙酯法检测对虾血淋巴中呼吸爆发活性,采用副溶血弧菌对剩余对虾进行攻毒,统计对虾死亡率。试验结果显示,拟诺卡氏菌细胞壁骨架能够明显促进凡纳滨对虾的生长,显著提高对虾血淋巴和肝胰腺中的超氧化物歧化酶、一氧化氮合酶、酚氧化酶、溶菌酶、谷胱甘肽过氧化物酶的活性( P <0.05, P <0.01),显著降低丙二醛浓度( P < 0.01 ),显著增强对虾血淋巴的呼吸爆发活性( P <0.05, P <0.01),可提高对虾的免疫保护率,从而提高凡纳滨对虾的存活率。研究结果表明,拟诺卡氏菌细胞壁骨架的适宜添加量为0.1%。

Effects of Nocardiopsis Cell Wall Skeleton on Growth and Immunity of Pacific White Shrimp Litopenaeus vannamei

Nocardiopsis lucentensis separated and purified in a laboratory was extended and cultured,and white cell wall skeleton was obtained from the fermentation broth by ultrasonic breaking,centrifugation,trypsin hydrolysis,degreasing and freeze-drying. Pacific white shrimp Litopenaeus vannamei with body weight of (4.21±1.28) g were fed diets containing 0.1% and 0.2% cell wall skeleton for 4 weeks when final body weight,survival rates,and the activities of superoxide dismutase,nitric oxide synthase,phenoloxidase,lysozyme,and glutathione peroxidase and malondialdehyde levels in hemolymph and hepatopancreas were measured in the shrimp in all treatment groups using the kits. The respiratory burst activity in shrimp hemolymph was determined by PMA method,and the remaining shrimp were challenged with Vibrio parahaemolyticus . The cell wall skeleton was shown to significantly promote the growth of Pacific white shrimp,to significantly increase activities of superoxide dismutase,nitric oxide synthase,phenoloxidase,lysozyme,and glutathione peroxidase in hemolymph and hepatopancreas ( P <0.05, P < 0.01 ),to significantly decrease the concentration of malondialdehyde ( P <0.01),and to significantly enhanced respiratory burst activity in hemolymph ( P <0.05, P <0.01),obviously improving the immune protection rate of the shrimp,thus greatly improving the survival rate of Pacific white shrimp. It is recommended that 0.1% be the appropriate amount of Nocardiopsis cell wall skeleton in diet.