Ittisupornrat Suda, Tobino Tomohiro, Yamamoto Kazuo
Department of Urban Engineering, The University of Tokyo, Tokyo, Japan,
Appl Microbiol Biotechnol. 2014 Nov;98(21):9107-18. doi: 10.1007/s00253-014-5914-1. Epub 2014 Jul 13.
Inclined plate membrane bioreactors (ip-MBRs) have been proposed as a highly effective method in wastewater treatment. With the help of settling enhancer inclined plates, dense excess sludge can be kept in the mainstream of the process, and consequently, suitable sludge mass can be maintained in the membrane tank. In this study, the relationship among sludge retention time (SRT), bacterial communities, and hydrolytic enzyme activities was investigated. Two identical bench-scale ip-MBRs were operated 1 year in real municipal wastewater treatment. Multidimensional scaling (MDS) plots of terminal restriction fragment length polymorphism (T-RFLP) fingerprints showed similar changes in the bacterial communities in terms of bacterial members and abundance over time in both the reactors, which was primarily caused by the changes of wastewater composition. However, the impact of SRT revealed significant differences in the dominant bacterial communities when both the reactors were operated with a largely different SRT (infinite SRT and SRT of 20 days). The sequences of bacterial 16S rRNA gene were classified into six libraries of A-F. The largest group of sequences belonged to the phylum Proteobacteria. The phylum Bacteroidetes was dominant in the seed sludge retrieved from the conventional activated sludge (CAS) as Flavobacterium-like bacterium was dominantly observed. Under the MBR operation (libraries B-F), bacterial communities belonging to the phyla Proteobacteria and Chloroflexi were dominant. Most of them may be responsible for protein degradation because aminopeptidase activity increased in proportion with the abundance of these bacteria.
倾斜平板膜生物反应器（ip-MBRs）已被提议作为一种高效的废水处理方法。在沉降增强器倾斜平板的帮助下，浓密的剩余污泥可以保留在工艺主流中，因此，膜池中可以维持合适的污泥量。在本研究中，研究了污泥停留时间（SRT）、细菌群落和水解酶活性之间的关系。两个相同的实验室规模的ip-MBRs在实际城市污水处理中运行了1年。末端限制性片段长度多态性（T-RFLP）指纹图谱的多维尺度分析（MDS）图显示，两个反应器中细菌群落的细菌成员和丰度随时间的变化相似，这主要是由废水成分的变化引起的。然而，当两个反应器以显著不同的SRT（无限SRT和20天的SRT）运行时，SRT的影响揭示了优势细菌群落的显著差异。细菌16S rRNA基因序列被分类为A-F六个文库。最大的序列组属于变形菌门。拟杆菌门在从传统活性污泥（CAS）中提取的种子污泥中占主导地位，因为主要观察到类黄杆菌。在MBR运行条件下（文库B-F），属于变形菌门和绿弯菌门的细菌群落占主导地位。它们中的大多数可能负责蛋白质降解，因为氨肽酶活性与这些细菌的丰度成比例增加。
