5种乳酸菌对奥尼罗非鱼免疫和抗病力的影响

摘要

选用体质量约3．49 g的奥尼罗非鱼，分别投喂基础饲料（空白组）和添加相同水平的嗜酸乳杆菌、植物乳杆菌、戊糖乳杆菌、鼠李糖乳杆菌、粪肠球菌的试验饲料。饲料中的乳酸菌数分别为1．30×103、5．10×108、2．97×108、3．03×108、2．30×108、3．47×108 cfu／g ，养殖期为8周，试验结束后采集血液并留部分鱼进行72 h的嗜水气单胞菌感染试验，计算72 h内的存活率。结果显示，植物乳杆菌组、戊糖乳杆菌组、鼠李糖乳杆菌和粪肠球菌组血清碱性磷酸酶活性均有不同程度升高，其中戊糖乳杆菌组最高，且显著高于嗜酸乳杆菌组；鼠李糖乳杆菌和粪肠球菌组血清抗超氧阴离子自由基能力显著高于其他各组；鼠李糖乳杆菌组血清溶菌酶活性显著高于空白组。注射嗜水气单胞菌12 h后，各添加组罗非鱼存活率均高于空白组，24～48 h ，鼠李糖乳杆菌组和粪肠球菌组存活率显著高于空白组，72 h时鼠李糖乳杆菌组存活率显著高于空白组。饲料中添加乳酸菌能提高奥尼罗非鱼免疫、抗氧化能力及抗嗜水气单胞菌感染能力，其中鼠李糖乳杆菌和粪肠球菌效果显著。%The experiment was conducted to study the effects of homology Lactobacillus preparation with different strains in diets on immune ,antioxidant and resistance against Aeromonas hydrophila .The tilapia hybrid (Oreochromis niloticus × O . aureu) with initial body weighg of 3 .49 g were fed the basal diet in control group ,and fed the basal diet containing L .acidophilus ,L .plantarum ,L .pentosus ,L .rhamno-sus and Enterococcus f aecalis in the other five groups for 8 weeks .The number of live lactic acid bacteria in each L actobacillus used in the experiment was 1 .30 × 103 ,5 .10 × 108 ,2 .97 × 108 ,3 .03 × 108 ,2 .30 × 108 and 3 .47 × 108 cfu /g ,respectively .At the end of the feeding test ,the fish were infected with Aeromonas hydrophila for 72 hours .The serum acid phosphatase activity was increased in varying degrees ,the maxi-mum in L .p lantarum group ,L .pentosus group ,L .rhamnosus group and E . f aecalis group in L .pento-sus group the highest was ,significantly higher than that in L .acidophilus group .The serum antisuperox-ide anion free radical activities were increased significantly ,higher in L .rhamnosus and E .f aecalis groups compared with the others .The activity of serum lysozyme was significantly higher in L .rhamnosus group than in the control group .During injection of A .hydrophilain 12 h ,the survival rate was higher in Lacto-bacillus groups than in the control ,no significant difference .In 24 and 48 hours ,survival rate were sig-nificantly higher in the L . rhamnosus and E . f aecalis groups than control group .In 72 hours ,survival rate in the L .rhamnosus group was significantly higher than control group .The results suggested that the supplementation of L actobacillus into the practical diet enhanced anti-oxidation ,and immune capacity and improved the resistance against A .hydrophila in tilapia .