Wong Man-Tak, Tan Fea Mein, Ng Wun Jern, Liu Wen-Tso
Environmental Science and Engineering Program and Department of Civil Engineering, National University of Singapore, Singapore 117576.
Microbiology (Reading). 2004 Nov;150(Pt 11):3741-3748. doi: 10.1099/mic.0.27291-0.
In an acetate-fed anaerobic-aerobic membrane bioreactor, a deteriorated enhanced biological phosphorus removal (EBPR) community was developed (as determined based on the chemical profiles of organic substrate, soluble phosphate, and intracellular carbohydrate and polyhydroxyalkanote (PHA) concentrations). Microscopic observations revealed the dominance of tetrad-forming organisms (TFOs), of which the majority stained positively for PHA under anaerobic conditions. Fluorescence in situ hybridization (FISH) confirmed that the Alphaproteobacteria (85.0+/-7.0% of total cells) were the most dominant group. A 16S rRNA gene clone library specific for the Alphaproteobacteria indicated that most 16S rRNA gene clones (61% of total clones) were closely affiliated with 'Defluvicoccus vanus', forming a cluster within subgroup 1 of the Alphaproteobacteria. Combined PHA staining and FISH with specific probes designed for the members of the 'Defluvicoccus' cluster suggested diversity within this TFO cluster, and that these TFOs were newly identified glycogen-accumulating organisms in EBPR systems. However, these 'Defluvicoccus'-related TFOs were only seen in low abundance in 12 different EBPR and non-EBPR systems, suggesting that they were not the key populations responsible for the deterioration of full-scale EBPR processes.
在以乙酸盐为食的厌氧-好氧膜生物反应器中，形成了一个退化的强化生物除磷（EBPR）群落（根据有机底物、可溶性磷酸盐以及细胞内碳水化合物和聚羟基链烷酸酯（PHA）浓度的化学特征确定）。显微镜观察显示四联形成菌（TFOs）占主导地位，其中大多数在厌氧条件下对PHA染色呈阳性。荧光原位杂交（FISH）证实，α-变形菌纲（占总细胞数的85.0±7.0%）是最主要的菌群。针对α-变形菌纲的16S rRNA基因克隆文库表明，大多数16S rRNA基因克隆（占总克隆数的61%）与“瓦氏脱卤球菌（Defluvicoccus vanus）”密切相关，在α-变形菌纲的第1亚组内形成一个簇。结合PHA染色以及使用为“脱卤球菌”簇成员设计的特异性探针进行FISH分析，表明该TFO簇内存在多样性，并且这些TFO是EBPR系统中新鉴定出的糖原积累菌。然而，在12个不同的EBPR和非EBPR系统中，这些与“脱卤球菌”相关的TFO仅以低丰度出现，这表明它们不是导致全规模EBPR工艺退化的关键种群。
