A3α-肽聚糖对凡纳滨对虾磷酸酶及细胞内酚氧化酶活性的影响

为考察A3α-肽聚糖(Peptidoglycan,PG)在凡纳滨对虾(Litopenaeus vannamei)的养成期对其免疫酶活性的影响,设立了连续投喂、间隔投喂和浸浴共6个实验组。连续投喂组中PG的添加量分别为0(对照)、0.01%、0.05%和0.1%;间隔投喂组中PG的添加量为0.05%;浸浴组的给予方式为50mg/ml,3h/次/15d。分别在30、60和90d时,测定对虾体内及血浆上清中的酸性磷酸酶(Acid phosphatase,ACP)和碱性磷酸酶(Alkaline phosphatase,AKP)活性,另外,在60d和90d时,测定对虾血细胞内酚氧化酶(Phenoloxidase,PO)活性。结果表明,30d时,PG浸浴组、0.05%和0.1%PG添加量组的ACP活性,各PG作用组的AKP活性均较对照组高,且0.1%PG添加量组的ACP活性及0.05%和0.1%PG添加量组的AKP活性较对照组增长显著(P<0.05);60d时,除间隔投喂组外,各组的ACP活性均较对照组高,且0.1%PG添加量组增长显著(P<0.05),而各实验组的AKP活性均较对照组高,且0.05%PG添加量组增长显著(P<0.05),除浸浴组外,各组血细胞内PO活性均有提高;90d时,浸浴组和间隔组的ACP和AKP活性均较对照组高,且间隔投喂组的AKP活性增长显著(P<0.05);间隔投喂组的血细胞内PO活性较对照组有增长。实验证明,PG能激活对虾的免疫力,并可作为免疫增强剂应用于对虾的生产。

Effects of A3α-peptidoglycan on activities of phosphatase and intracellular phenoloxidase of Litopenaeus vannamei

Six experiment groups, including the groups of continuous feeding, discontinuous feeding and immersing, were set up for evaluating the effects of PG on the activities of immunity enzymes of Litopenaeus vannamei. The contents of PG in diets were 0, 0.01 %, 0.05 % and 0.1 % for the groups of continuous feeding, and 0.05 % for the discontinuous feeding group. As for the immersion groups, Litopenaeus vannamei was immersed in 50 mg/ml PG, 3 h/per time/l5 d. On the 30th, 60th and 90th day, the activities of ACP and AKP in both shrimp and plasma supernatant were determined. In addition, the activities of intracellular PO were also determined on the 30th and 60th day. The results showed that the ACP activities in the groups of immersing and feeding with the diet containing 0.05 % and 0.1 % PG, and the AKP activities in all groups were higher than those in the control on the 30th day. Among them, the ACP activities in the group of feeding with the diet containing 0.1 % PG and the AKP activities in the groups of feeding with the diet containing 0.1 % and 0.05 % PG increased significantly (P<0.05), compared to the control. The ACP activities in all groups except discontinuous feeding group and the AKP activities in all groups were all higher than those in the control on 60th day. Among them, the ACP activities in the group of feeding with the diet containing 0.1 % PG and the AKP activities in the group of feeding with the diet containing 0.05 % PG increased significantly (P<0.05), compared to the control. The activities of intracellular PO in all groups except the immersing group were higher than those in the control group. On 90th day, both the ACP and AKP activities in the groups of immersing and discontinues feeding were higher than those in the control, the AKP activities in the group of discontinues feeding being significantly higher (P<0.05). Besides, the activities of intracellular PO of shrimp in the group of discontinues feeding were somewhat higher than those in the control group. The experiment proved that PG could stimulate the immunity system of shrimp, and can be used as immunity intensifier for shrimp cultivation.