斑石鲷循环水养殖系统生物滤池微生物群落对水质变化的动态响应

为了解斑石鲷循环水养殖系统生物滤池内部细菌群落组成及其净水机制，通过高通量测序方法，研究了不同时期各级生物滤池的细菌群落结构，分析了各级生物滤池的水质参数及水处理效果。结果表明：实验筛选出37 个门和513个细菌属，第3级生物滤池整体微生物群落丰富度和多样性均高于第1级和第2级生物滤池，第2级和第3级生物滤池微生物群落相似性最高。在门水平上，优势菌为变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi)、拟杆菌门(Bacteroidetes)；在属水平上，发现了起硝化作用的亚硝化单胞菌属Nitrosomonas和硝化螺菌属Nitrospira；实验还发现该系统生物滤池可能存在功能上的浪费现象。该系统的细菌群落结构有稳定的演替模式，生物膜微生物群落变化对水质有一定程度的动态响应，Muricauda、Maribacter等反硝化细菌对硝态氮浓度的变化作用不明显。

Dynamic response of microbial community to water quality change in biofilter for recirculating aquaculture system of Oplegnathus punctatus

In order to learn the bacterial community composition and water purification mechanism in biofilter for recirculating aquaculture system of Oplegnathus punctatus, the high-throughput sequencing method was used to study the evolution of bacterial community structure in the biofilters at different stages, and the water quality parameters and water treatment effects of these biofilters were also analyzed. The results showed that bacterial 37 phyla and 513 genera were screened out by the experiment. The overall microbial community richness and diversity of the third-stage biofilter were higher than those of the first- stage and second-stage biofilters. The microbial communities in the second-stage and third-stage biofilters had the highest similarity. At the phylum level, the dominant bacteria were Proteobacteria, Chloroflexi, Bacteroidetes. At the genus level, Nitrosomonas and Nitrospira were found to perform nitrifying. Morover, some functional waste phenonmena occurred in the biofilter of the system. The analysis indicated that a stable succession pattern existed in the bacterial community structure of this system, and a certain degree of dynamic response of the change of biofilm microbial community to water quality also happened. Denitrifying bacteria such as Muricauda and Maribacter had no obvious effect on the change of nitrate nitrogen concentration.