Study On Intestinal Microbiota Of Wild And Cultured Coreius Guichenoti

Largemouth bronze gudgeon(Coreius guichenoti)belongs to Cyprinidae,Gotiongiae and Coreius.It has a large population.It is an important economic fish peculiar to the upper reaches of the Yangtze River in China and has been a major fishing object.In recent years,the economic development in the upper reaches of the Yangtze River has destroyed the ecology of the upper reaches of the Yangtze River,and the number of Coreius guichenoti has decreased sharply.Intestinal microorganisms are closely related to the nutrition and health of the host.Normal intestinal microflora can help the host digest better and absorb nutrients,promote the proliferation of intestinal epithelial cells,benefit the development of intestinal related lymphoid tissue,and participate in its immune regulation.At present,the intestinal microorganisms of human and livestock are widely studied at home and abroad,but the intestinal microflora of fish is seldom studied.It is important to study the structure and composition of intestinal microflora for the prevention and control of fish diseases,the regulation of intestinal microflora structure,and the improvement of fish production and feed utilization.In this study,The total DNA of intestinal microbial of cultured,different feeding intensity and wild environment were determined by next generation sequencing(NGS).16S rRNA was used to analyze the microbial diversity,relative abundance and diversity.The 16S functional prediction,PICRUSt(phylogenetic investigation of communities by reconstruction of unobserved states)technique,was used to predict the intestinal tract of cultured Coreius guichenoti.Samples were analyzed for functional genes.To explore the diversity of intestinal microflora of Coreius guichenoti,in order to facilitate artificial domestication of it and research and development of feed additives;to provide theoretical basis for understanding the factors affecting intestinal microbial composition,and to explore the function of intestinal microorganisms in intestinal tract,and to develop probiotics and microecological.The results are as follows:(1)There was no significant difference between the foregut and midgut samples(Figure 2-4)and the hindgut samples(One-way ANOVA,P<0.05),and the microbial diversity in the midgut was the highest(Chao:240,Shannon:2.28)among the different parental and offspring of cultured largemouth bronze gudgeon,followed by the foregut and hindgut.Proteobacteria is the dominant phylum in relative abundance,accounting for 70.17%of the total microorganisms,but there are differences in different parts of the intestine.Tenericutes is the dominant phylum in the hindgut,Proteobacteria is the dominant phylum in the foregut and midgut,and Halomonas is the dominant phylum in genus level.The dominant genus in the foregut and midgut was Halomonas,and the latter was Mycoplasma.(2)By analyzing the intestinal microbiota in different wild environments,it was found that there were some differences in the diversity of intestinal microflora in different intestinal parts(One-way ANOVA,P<0.05),and the highest diversity was found in foregut sample of Jinanqiao(Chao:336),followed by midgut sample of Jinanqiao and Yibin;generally speaking,the intestinal microflora in Jinanqiao samples were observed.Diversity is higher than Yibin sample.It was also found that the order of microbial diversity was foregut>midgut>hindgut.Proteobacteria accounted for 64.18%of the intestinal flora in Yibin,77.00%of the intestinal microbiota in Jinanqiao,21.21%of the intestinal flora in Yibin and 31.75%of the intestinal microflora in Jinanqiao.(3)In order to further understand the intestinal tract information,we investigated the intestinal flora composition of two different feeding intensities of Coreius guichenoti,and found that Proteobacteria was still the dominant phylum of the two group sample.The dominant bacteria in the intestine of feeding normal group Aeromonas and Mycoplasma were normal feeding at the generic level accounted for 41.79%and 39.29%of the total microbial content respectively,while the dominant bacteria in the intestine of feeding abnormal group that were Mycoplasma and Halomonas accounting for 29.80%and 20.80%of the total microbial content respectively.In addition,the diversity of intestinal flora in the normal feeding group was lower than that in the abnormal feeding group.(4)By comparing KEGG database and 16S function prediction method,the types of microbiota participating in host metabolism in different intestinal parts of cultured and wild Coreius guichenoti were compared at L1 level.It was found that there was no significant difference in metabolic types between foregut and hindgut,and there was significant difference in the types of foregut,midgut and hindgut.In the cultured group,the metabolic types of the anterior and posterior intestines were the same as those of the middle and posterior intestines,including Metabolism,Human Diseases,Cellular Processes,Organismal Systems,and Genetic Information Processing.Environmental information processing and unclassified were found in the wild group;but only the metabolic were the same.There was only one metabolic difference between wild and cultured samples at L1 level,while there were cell growth and death,Enzyme Families and Metabolism at L2 level.