同步脱氮除磷系统中两种颜色好氧颗粒污泥的微生物群落特征

为研究同步脱氮除磷系统中出现的WG（白色好氧颗粒污泥）外形特点及微生物群落特征，探究其成因，利用SEM（扫描电子显微镜）表征了系统中的WG与YG（黄色好氧颗粒污泥）的微观形态，并采用Illumina HiSeq 2500高通量测序平台对两种好氧颗粒污泥中细菌与真菌的群落组成进行研究.结果表明:WG结构疏松外形不规则，颗粒表面分布大量杆菌；而YG饱满紧实轮廓清晰，颗粒表面分布大量球菌.WG与YG的细菌群落组成相似，但真菌组成差异较大.与YG相比，WG具有更高的细菌和真菌多样性.变形菌门（Proteobacteria）和拟杆菌门（Bacteroidetes）为WG和YG中的细菌优势门，其在WG中的相对丰度分别为68.85%和26.61%，在YG中的相对丰度分别为82.52%和12.30%.Candidatus competibacter、Candidatus accumulibacter和Chiayiivirga为WG中的优势属，相对丰度分别为22.13%、8.95%和7.37%；Candidatus competibacter、Chiayiivirga和Xanthomonas为YG中的优势属，相对丰度分别为47.94%、6.95%和7.06%.子囊菌门（Ascomycota）和Rozellomycota分别为WG与YG中真菌优势门，其在两个样品中的相对丰度分别为50.10%和81.77%.在属水平，WG中存在大量青霉属（Penicillium）和假丝酵母属（Candida）等丝状真菌，为WG的形成提供了框架.研究显示，当YG破碎成为小菌胶团后，附着在真菌框架上，造成了WG的快速形成，同时WG中Candidatus competibacter的相对丰度较低，使其外形疏松、透光性较好，呈现出白色. 

White and Yellow Aerobic Granular Sludge Microbial Structures Appearing in a Simultaneous Nitrogen and Phosphorus Removal System Using High-Throughput Sequencing

In a simultaneous nitrogen and phosphorus removal system, both white and yellow aerobic granular sludge (WG and YG) appeared. Scanning electron microscopy (SEM) was used to observe the micro-morphology of WG and YG. Illumina HiSeq 2500 platform was applied to investigate their bacterial and fungal communities, and to explore the reasons for the formation of WG. WG was loose and irregular, while YG was compact and regular. The results of SEM indicated that bacillus and coccus were dominant on the surface of WG and YG, respectively. The bacterial community of WG and YG was similar, while their fungal community was significantly different. The α-diversity of WG was higher than that of YG. Proteobacteria and Bacteroidetes were the dominant phyla in WG and YG. Their relative abundances in WG were 68.85% and 26.61%, respectively. For YG, their relative abundances were 82.52% and 12.30%, respectively. Candidatus competibacter(22.13%), Candidatus accumulibacter (8.95%) and Chiayiivirga (7.37%) dominated in WG. Candidatus competibacter(47.94%), Chiayiivirga (6.95%) and Xanthomonas (7.06%) were the dominant genera in YG. Ascomycota and Rozellomycota were the main fungal phyla in WG and YG, with relative abundances of 50.10% and 81.77%, respectively. Penicillium and Candida were the dominant filamentous fungi in WG. When YG disintegrated into small zoogloea, it attached to the framework of filamentous fungi and grew rapidly, which might be a reason for the formation of WG. The low relative abundance of Candidatus competibacter might be a reason for the loose shape of WG.