Analysis And Utilization Of Intestinal Flora In Litopenaeus Vannamei

In recent years,diseases of Litopenaeus vannamei occurs frequently due to environmental pollution and degradation of germplasm,and drug resistance and drug residues caused by the large number of antibiotics,causing huge economic losses to farmers,seriously affected healthy and stable development of the shrimp farming.In order to solve aquaculture diseases and food safety,and many other contradictions,finding new green alternatives to antibiotics has become a research hotspot.In the study,main microflora composition of shrimp intestinal and water were analyzed using high-throughput sequencing technology,and dorminant microorganism was selected for preparing probiotics,then effect of probiotics on immune function and intestinal flora of L.Vannamei was studied,the main results and conclusions were as follows:1.The main microflora composition of shrimp intestinal and water were analyzed using high-throughput sequencing technology,and it was determined that main microflora were Proteobacteria,Bacteroidet,Actinobacteria and Firmicutes,and minor bacterial flora were Chlamydiae and Planctomycetes.The proportion of various microflora was different,the proportion of shrimp intestinal were:Proteobacteria 42.44%,Bacteroidet 46.57%,Actinobacteria 2.21%,Firmicutes 4.57%,Chlamydiae 0.23%,Planctomycetes 0.03%.The proportion of bacterial flora composition in aquaculture water were:Proteobacteria 57.74%,Bacteroidet 18.27%,Actinobacteria 8.42%,Firmicutes 8.59%,Chlamydiae 0.58%,Planctomycetes 0.15%,Chloroflexi 0.05%,Nitrospirae 0.03%.Chloroflexi and Nitrospirae specially existed in the aquaculture water.2.Bacillus and bifidobacteria were added to the feed of Litopenaeus vannamei,and fed for 4 weeks,effects of probiotics on immunologic functions and intestinal microflora of L.Vannamei was studied by Nanjing Jiancheng kit and denaturing gradient gel electrophoresis(DGGE)technology.The results showed that probiotics could obviously increase activities of peroxidase,superoxide dismutase,nitric oxide synthase,acid phosphatase and alkaline phosphatase in L.Vannamei serum,obviously improve intestinal bacteria group composition of the shrimp,so as to improve the ability of shrimp to resist disease.