Analysis And Comparison On Intestinal Microbiota Of Sea Cucumber Apostichopus Japonicus From Different Habitats In Spring In Liaoning Province

Intestinal microbes play key roles in growth and immunity of the host by maintaining the microecology.Intestinal flora is considered to have the ability to maintain the intestinal micro ecology in including stimulate the immune and competition of nutrition,pathogen binding sites,produce antibacterial substances,and promote the growth of beneficial species such as to maintain the intestinal micro ecological stability.Sea cucumber(Apostichopus japonicus Selenka)is a common sea economic species,and at the same time have a certain scientific research value.But the research on sea cucumber intestinal colonization flora is relatively rare.In this thesis,the intestinal flora of the sea cucumbers A.japonicus were detected by 16 S rDNA sequence after the contests were removed.Sea cucumbers were collected from Zhangzidao Island(ZZD),Dandong(DD)and Zhuanghe(ZH)at the Yellow Sea,Huludao Island(HLD)at the Bohai Sea,and Lvshun(LS)at the confluence of the Yellow Sea and the Bohai Sea(3 sea cucumbers per habitat).Sea cucumbers in group ZZD and LS were wild cultured,and the other three were Artificial cultured.A total of 952 005 Effective Tags was clustered into 27 117 operational taxonomic units(OTUs);Proteobacteria was found the predominant phylum,while dominant genera were different from different habitats.Halomonas was the predominant genus for groups at the Yellow Sea and the Bohai Sea(DD,36.97%,ZZD,42.66%,ZH,31.73%,HLD,31.96%),followed by Shewanella(DD,9.13%,ZZD,14.34%,ZH,9.56%,HLD,8.95%);and phylum Bacteroidetes genus Bacteroides(3.72%)was dominant at the confluence of the Yellow Sea and the Bohai Sea.According to Alpha diversity results,more species were observed in group LS,as well as the highest community diversity;lowest community diversity was observed in group ZZD;lowest community richness was observed in group DD.According to Beta diversity results,group LS was different from the other four groups,group ZZD and HLD were relatively similar.Relative abundances of Proteobacteria,Halomonas and Shewanella of group from the confluence of the Yellow Sea and the Bohai Sea were significant lower than group from the Yellow Sea and group from the Bohai Sea(P<0.05);relative abundances of Bacteroidetes,Gemmatimonadetes,Verrucomicrobia,Planctomycetes and Bacteroides of group from the confluence were significant higher than the other two groups(P<0.05).Shannon,Chao1 and ACE indexes of group from the confluence were significant higher than the other two groups(P<0.05).Moreover,some beneficial bacteria such as lactic acid bacteria and Bifidobacterium were detected with the proportion from 0.58% to 4.66% from all the samples.Relative abundances of Acidobacteria,Actinobacteria,Gemmatimonadetes,Verrucomicrobia and Planctomycetes in wild group were higher than cultured group(P<0.05).Results in this topic exhibit the relationship between intestinal flora of healthy sea cucumbers and their habitats,which may become directions for probable probiotics development and utilization and providing technical support for dissimilation culture of sea cucumber.