Environmental Biotechnology Lab, The University of Hong Kong SAR, Hong Kong, China.
Environ Microbiol Rep. 2014 Feb;6(1):80-9. doi: 10.1111/1758-2229.12110. Epub 2013 Oct 21.
Metagenomic technique was employed to characterize the seasonal dynamics of activated sludge (AS) communities in a municipal wastewater treatment plant (WWTP) over 4 years. The results indicated that contrary to Eukaryota (mainly Rotifera and Nematoda), abundances of Bacteria and Archaea (mainly Euryarchaeota) were significantly higher in winter than summer. Two-way analysis of variance and canonical correspondence analysis revealed that many functionally important genera followed strong seasonal variation patterns driven by temperature and salinity gradients; among them, two nitrifying bacteria, Nitrospira and Nitrosomonas, displayed much higher abundances in summer, whereas phosphate-removing genus Tetrasphaera, denitrifier Paracoccus and potential human faecal bacteria, i.e. Bifidobacterium, Dorea and Ruminococcus, showed significantly higher abundances in winter. Particularly, occurrence of dual variation patterns beyond explanation merely by seasonality indicated that multivariables (e.g. dissolved oxygen, sludge retention time, nutrients) participated in shaping AS community structure. However, SEED subsystems annotation showed that functional categories in AS showed no significant difference between summer and winter, indicating that compared with its microbial components, the functional profiles of AS were much more stable. Taken together, our study provides novel insights into the microbial community variations in AS and discloses their correlations with influential factors in WWTPs.
采用宏基因组学技术,在四年时间内研究了城市污水处理厂(WWTP)中活性污泥(AS)群落的季节性动态。结果表明,与真核生物(主要是轮虫和线虫)相比,细菌和古菌(主要是广古菌门)的丰度在冬季明显高于夏季。双向方差分析和典范对应分析显示,许多功能重要的属受到温度和盐度梯度驱动的强烈季节性变化模式的影响;其中,两种硝化细菌(硝化螺旋菌和亚硝化单胞菌)在夏季的丰度更高,而除磷属 Tetrasphaera、反硝化菌 Paracoccus 和潜在的人类粪便细菌(双歧杆菌、Dorea 和 Ruminococcus)在冬季的丰度更高。特别是,超出季节性解释的双重变化模式表明,多变量(如溶解氧、污泥停留时间、营养物)参与了 AS 群落结构的形成。然而,SEED 亚系统注释显示,AS 中的功能类别在夏季和冬季之间没有显著差异,这表明与微生物组成相比,AS 的功能谱更加稳定。综上所述,本研究为 AS 中微生物群落的变化提供了新的见解,并揭示了它们与 WWTP 中影响因素的相关性。