Long solids retention times and attached growth phase favor prevalence of comammox bacteria in nitrogen removal systems
Long solids retention times and attached growth phase favor prevalence of comammox bacteria in nitrogen removal systems
复制标题
DOI：
10.1016/j.watres.2019.115268
复制
发表时间：
2020-02-01
期刊：
影响因子：
12.8
通讯作者：
Pinto, Ameet J.
中科院分区：
文献类型：
--
作者：
Cotto, Irmarie;Dai, Zihan;Pinto, Ameet J.
完全氨氧化（comammox）细菌的发现颠覆了传统的二生物硝化范式，该范式在很大程度上支撑了废水处理过程中脱氮的设计和操作。量化废水处理系统中comammox细菌的丰度、多样性和活性对于确保清楚地了解负责氨去除的氮生物转化非常重要。为此，我们对14个全规模脱氮系统进行了为期一年的调查，包括具有不同工艺配置的主流常规和同步硝化-反硝化系统以及侧流部分硝化-厌氧氨氧化系统。宏基因组学和基因组解析宏基因组学在主流常规和同步硝化-反硝化系统中发现了comammox细菌，但没有证据表明它们存在于侧流部分硝化-厌氧氨氧化系统中。此外，comammox 细菌多样性仅限于 Glade A，并且这些 Glade A comammox 细菌在具有长固体保留时间（> 10 天）的系统和/或在附着生长期中检测到。使用新设计的针对 Glade A comammox 细菌 amoB 基因的 qPCR 检测方法，结合其他典型硝化菌的定量，我们发现长固体保留时间是与comammox 细菌的流行和丰度相关的关键过程参数。 comammox 细菌丰度的增加与典型硝化菌丰度的随之减少无关；然而，与未检测到comammox细菌的系统相比，含有comammox细菌的系统显示出明显更好且暂时稳定的氨去除效果。最后，与最近的研究相比，我们在这项研究中没有发现comammox细菌的流行率和丰度与溶解氧浓度有任何显着关联。 (C) 2019 Elsevier Ltd. 保留所有权利。
The discovery of the complete ammonia oxidizing (comammox) bacteria overturns the traditional two-organism nitrification paradigm which largely underpins the design and operation of nitrogen removal during wastewater treatment. Quantifying the abundance, diversity, and activity of comammox bacteria in wastewater treatment systems is important for ensuring a clear understanding of the nitrogen bio-transformations responsible for ammonia removal. To this end, we conducted a yearlong survey of 14 full-scale nitrogen removal systems including mainstream conventional and simultaneous nitrification-denitrification and side-stream partial nitrification-anammox systems with varying process configurations. Metagenomics and genome-resolved metagenomics identified comammox bacteria in mainstream conventional and simultaneous nitrification-denitrification systems, with no evidence for their presence in side-stream partial nitrification-anammox systems. Further, comammox bacterial diversity was restricted to Glade A and these Glade A comammox bacteria were detected in systems with long solids retention times (>10 days) and/or in the attached growth phase. Using a newly designed qPCR assay targeting the amoB gene of Glade A comammox bacteria in combination with quantitation of other canonical nitrifiers, we show that long solids retention time is the key process parameter associated with the prevalence and abundance of comammox bacteria. The increase in comammox bacterial abundance was not associated with concomitant decrease in the abundance of canonical nitrifiers; however, systems with comammox bacteria showed significantly better and temporally stable ammonia removal compared to systems where they were not detected. Finally, in contrast to recent studies, we do not find any significant association of comammox bacterial prevalence and abundance with dissolved oxygen concentrations in this study. (C) 2019 Elsevier Ltd. All rights reserved.