乳酸菌对罗非鱼肠道微生物菌群组成和抗病能力的影响.doc

乳酸菌对罗非鱼肠道微生物菌群组成和抗病能力的影响 08生物工程 任君爽 指导老师：刘枝 摘要 本试验以罗非鱼为研究对象，在基础日粮中添加乳酸菌，探讨对罗非鱼肠道微生物菌群组成和抗病能力的影响。试验选择720尾健康的罗非鱼(初重为5-10g)随机分成6组，分别投喂6种不同的饲料，每组设4个重复，每个重复30尾。在日粮中添加乳酸杆菌为106、107、108、109、1010cfu/g。在饲养7周，每个处理选取30尾鱼进行肠道微生物菌群的检测和链球菌液攻毒实验，试验期为4d。试验结果表明，随着乳酸菌饲料中乳酸菌添加浓度的增加，罗非鱼肠道病菌数量逐步降低、益生菌数量逐步上升；在攻毒实验中，乳酸菌饲养组的抗病能力随乳酸菌添加浓度增大而提高。这说明乳酸菌饲料对提高罗非鱼肠道益生菌群数量和抗病能力有良好作用，从而为乳酸菌饲料在水产养殖业中的推广应用提供理论依据。 关键词 乳酸菌饲料；罗非鱼；肠道菌群；抗病能力 Effect of Lactobacillus fermentum in the diet on intestinal microflora and disease resistance in tilapia ren School of Life Sciences，Guangzhou University ABSTRACT The experiment was conducted to investigate the the effects of dietary Lactobaeillus fermenturn supplement on intestinal microflora and disease resistance in tilapia . In seven weeds feeding trial，a total of 720 tilapia(5-10g) were randomly distributed into six groups of each four replicates，feeding diets containing graded levels of Laetobacillus fermentum 1x106,1x107, 1x108, 1x109, 1x1010cfu/g diet.After the growth trial，30 fish in each treatment were randomly assigned to a challenge trial conducted by injection of Streptococcus iniae for 4 days. Results showed that the number of pathogenic bacteria reduced, the number of probiotics gradually increased and the disease resistance of tilapia was increased with the increasing of Lactobacillus fed. Lactobacillus can improve tilapia number of probiotics group and disease resistance, and thus provides the direction of application of Lactobaeillus fermenturn in the aquaculture. KEY WORDS Lactobacillus；tilapia；intestinal microflora；disease resistance 目录 前言………………………………………………………………………… 1 材料与方法………………………………………………………………… 3 2.1 实验材料……………………………………………………………… 3 2.1.1乳酸菌饲料的制备 ……………………………………………… 3 2.1.2 罗非鱼的饲养管理 ……………………………………………… 4 2.2 实验仪器……………………………………………………… 4 2.3 实验……………………………………………………………… 4 2.4 实验方法……………………………………………………………… 4 2.4.1 生长测定 ………………………………………………………… 4 2.4.2 涂布平板法检测罗非鱼肠道菌群……………………………… 4 2.4.2.1 样品