Community Structure, Biodiversity And Abundance Of Anaerobic Ammonia-oxidizing Bacteria In Typical Freshwater Aquaculture Ponds

With the rapid development of the aquaculture industry, the scale of farming isexpanding, the aquaculture species is growing, and the high-density intensive farmingmethod has got a large area promotion use. Its characteristics of high density, shortcycles and closed environments brings to the aquaculture water nutrient burden andcontaminate the whole breeding environment through influencing breeding ammonianitrogen content. Anaerobic ammonia oxidation （Anammox） can make toxicammonia and nitrate directly to harmless nitrogen, can effectively remove theammonia of aquaculture water. To understand the community structure, biodiversityand abundance of anammox bacteria in fish and shrimp aquaculture ponds withfreshwater in summer and winter in Chengyang aquaculture ponds of Qingdao, thehzo gene is opt as the functional marker gene. Combining with the determination ofthe environmental factors analysis, we assay the correlation of the abundance ofanammox bacteria hzo genes with environmental factors in order to know theanammox bacteria overall.12hzo gene libraries for anammox are constructed, and1210clones and39OTUs are divided at99%similarity level, indicates that thebiodiversity is not high in this breeding environment. The similarity of hzo gene mostsimilar sequences with the GenBank database is87%-100%. The most is linked toJiaojiang River sediments or its water column and Mai Po Nature Reserve coastalestuary surface sediment. The high library coverage and saturated rarefaction analysisof all the stations show high gene library information representatively. Station F4shows the highest abundance, while Station S3and S4show the lowest. The sedimentdiversity induces of all breeding stations in winter is higher than the correspondingsediment in summer. The Unifrac clustering analysis indicates that the summerbreeding stations has a relatively smaller difference when they gather together, while the winter breeding stations can gather together besides Station F2. Thus, there is asignificant seasonal characteristic. Combined with the cluster analysis results ofenvironmental factors, it reveals that the community structure of this area is a result ofinteraction between sediment interstitial water and sediment itself. Phylogenetic treeis divided into four Clusters, and it indicates that the anammox bacteria is mainlyaffiliates with the three known genus of Candidatus Kuenenia, Candidatus Scalinduaand Candidatus Jettenia. A relative concentration occurs in each Cluster of all thestations, more Candidatus Kuenenia in summer in river sediment while moreCandidatus Jettenia in winter, more Candidatus Jettenia in summer in settling pondwhile more Candidatus Scalindua in winter, more Candidatus Scalindua in summerin culture ponds while more Candidatus Jettenia in winter besides Station F2. Theaquaculture environment and the different season influence the structure of anammoxbacteria significantly. The abundance of the aquaculture sediment hzo genes rangesfrom4.73×10~7copies/g sediments to2.93×10~9copies/g sediments. The abundance ofthe aquaculture sediment hzo genes is high but does not show any significantcorrelation with any environmental factor measured.