Study On Microbial Community Structure And Its Diversity In Aquaponics Mode

Aquaponics technology is a new green technology type of safety and health and ecological environmental protection, which combines with aquaculture and hydroponics technology and the most typical application mode is Aquaponics Mode that combines with biological floating bed technology in C hina. The study investigated the microbial community structure and diversity and its changes of rhizosphere microbes, aquacultural environment microorganisms and the intestinal flora in Aquaponics Mode through the experiment using the method of metagenomics. The results revealed the effects of the bio- floating beds on microbial community structure and diversity in the fis h-vegetable culture mode, and made a scientific explanation for water quality regulating mechanism of bio- floating beds from the perspective of microorganisms, also provided theoretical foundations for popularization and application of biological regulation technology and healthy cultural technology for aquaculture.In order to explain the water quality regulating mechanism of bio- floating beds, the study investigated the microbial community structure and its diversity of the aquacultural environment microorganisms and rhizosphere microbes in a pond by Ipomoea aquatica floating-bed, and the composition and diversity of microbial communities in the samples were researched based on high throughput sequencing of 16 S r DNA. The results revealed that,compared with control group, the microbial communities in aquatic environments have high abundance and low diversity, and the microbes in sediment have high abundance and high diversity in Aquaponics Mode, which suggested Ipomoea aquatica biological floating bed changed the micro-ecological balance in the aquaculture environment effectively. The results revealed that the dominant microbial phyla were Proteobacteria, Cyanobacteria, Bacteroidetes, Actinobacteria, C hloroflexi, Firmicutes, Fusobacteria, Acidobacteria, Planctomycetes and C hlorobi in aquaculture environment and rhizosphere, and the dominant environmental microbial genera were Synechococcus, CL500-29_marine_group, hgc I_clade, Bacillus and Mycobacterium, and the dominant rhizosphere microorganisms of Ipomoea aquatica were Rhodobacter, Hydrogenophaga and Synechococcus in Aquaponics Mode. Moreover, the results also showed that low coverage(3.5%) of Ipomoea aquatica floating-bed could increase the dissolved oxygen content, reduce the concentration of nitrogen compounds and improve micro-ecological balance, and increase the content of the beneficial bacteria and nitrogen cycle bacteria in aquaculture water body.At the same time, in order to investigate the intestinal microbial community structure in different species of carp in Aquaponics Mode, 12 intestine samples of four species of carp(Ctenopharyngodon idellus, Carassius auratus, Hypophthalmichthys molitrix and Aristichthys nobilis) were collected from the same pond, and the composition and diversity of microbial communities in the samples were researched based on high throughput sequencing of 16 S r DNA. The results revealed that the dominant microbial phyla were Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes and Fusobacteria, the dominant microbial genuses were Cetobacterium, Clostridium, Bacteroides and Bacillus, and Cetobacterium and Clostridium were the most abundant core intestinal microbiotas in the four species of carp with different feeding habits; the composition, diversity and their relative proportion of these dominant microbial genera in different species of carp intestinal contents were very similar(P>0.05, Kruskal-Wallis), and the microbiota diversity difference existed between non-dominant microbial genera in the different species of carp(P<0.05, Kruskal-Wallis). Moreover, the results also showed that feeding habits was not the only key factor that affected the intestinal microbiota of carp with different feeding habits using the method of LEf SE analysis.In summary, by adopting the traditional research methods of Water Ecology, Metagenomics and Bioinformatics, this study researched the characteristics of Aquaponics Mode which has been seen as a new type of health ecological c ultural model from the angle of water chemistry and microbiology mainly, and conducted practice with Ipomoea aquatica Floating-Bed, provided a certain foundation of theory and practice for popularization and application of biological control technology and healthy cultural technology for aquaculture.