Effects Of Several Immunostimulants And Vaccine On The Activities Of Immunoenzyme And Disease Resistance Of Sea Cucumber, Apostichopus Japonicus

The effects of seaweed-sulfated polysaccharides, chitosan and different concentrations of C6 andTB formalin-inactivated whole-cell vaccine on the activities of acid phosphatase (ACP), alkaline phosphatase (AKP), lysozyme (LSZ) and superoxide dismutase (SOD) of Sea Cucumber were studied by supplying various levels in diets. The experimental dietary levels of seaweed-sulfated polysaccharides were 0.25%(m/m) seaweed-sulfated polysaccharides,0.5% seaweed-sulfated polysaccharides and 1.0% seaweed-sulfated polysaccharides, and those of chitosan were 0.5% chitosan, 1.0% chitosan and 2.0% chitosan respectively, while those of C6 and TB vaccine were 1×107CFU/mL, 1×108CFU/mL, 1×109CFU/mL respectively. On the 2nd, 5th, 9th and 15th day after feeding for 7 days, the activities of ACP, AKP, LSZ and SOD were determined; and then on the 16th day challenge experiments were done with 1.4×108 CFU/mL C6 Vaccine, the relative percentage survival were observated.About the experiments of immunopolysaccharide, the results indicated that the activities of ACP and AKP were both sustainly increased and had significantly different compared with control (P<0.05). The effects of 1.0% of seaweed-sulfated polysaccharides and 2.0% of chitosan on the activities of ACP and AKP were the best, the highest activities of ACP were 3 and 3.9, and of AKP were 2.3 and 4.4 times than that of control respectively. The activities of LSZ were increased firstly during the 15 days after feeding, with the tiptop significantly different compared with control (P<0.05). However, The activities of LSZ had not proportional relationship with the addition of immunopolysaccharide. The effects of 0.5% of seaweed-sulfated polysaccharides and 1.0% of chitosan on the activities of LSZ had the best results, the highest activities were 1.3 and 3.4 times respectively. The activities of SOD were all significantly enhanced on the 2nd day after feeding, and then decreased. The effects of 1.0% of seaweed-sulfated polysaccharides and 2.0% of chitosan on the activities of SOD were the best; the highest activities were 1.7 and 2.1 times respectively. The results of challenge experiments confirmed that all group have produced a certain RPS, and were proportional to the added concentration; The RPS of 1.0% of seaweed-sulfated polysaccharides and 2.0% of chitosan were best, with 30.4%,39.1% bigger than control. In conclusion, seaweed-sulfated polysaccharides and chitosan can regulate the antioxidant enzymes and hydrolytic enzymes, and improve the non-specific immunity of sea cucumber. Taking economy and efficiency into account, it is suggested that the feasible dosage should be 1.0% (m/m) of seaweed-sulfated polysaccharides and 2.0% (m/m) of chitosan.About the experiments of vaccine, the results indicated that the activities of ACP, AKP and LSZ were all sustainly increased; and with the increasing concentration of the vaccine the activities were increased; and had significantly different compared with the control (P<0.05). The effects of 1×109CFU/mL C6 vaccine and 1×109CFU/mL TB vaccine on the activities of ACP , AKP and LSZ were the best, the highest activities were 1.9 and 1.6, 2.9 and 1.9, 2.3 and 1.5 times than that of control respectively. However, the activities of SOD had gradually increased firstly and then gradually stabilized during the fifteen dys, and with the increasing concentration of the vaccine the activities were increased; but not significantly different compared with the control (P>0.05); 1×109CFU/mL C6 vaccine and 1×109CFU/mL TB vaccine on the activities of SOD were the best, the highest activities were 1.2 and 1.1 times than that of control. The results of challenge experiment confirmed that all group have produced a certain relative percentage survival, and proportional to the added concentration; The relative percentage survival of 1×109CFU/mL C6 vaccine and 1×109CFU/mL TB vaccine were best, with 50%,36.4% bigger than control. In conclusion, 1×109CFU/mL C6 vaccine and 1×109CFU/mL TB vaccine can regulate the antioxidant enzymes and hydrolytic enzymes, and improve the non-specific immunity of Sea Cucumber. Taking efficiency into account, it is suggested that the feasible dosage should be 1×109CFU/mL C6 vaccine and 1×109CFU/mL TB vaccine.