Department of Civil and Environmental Engineering, University of California Berkeley, Berkeley, CA, USA.
Tighe & Bond, Westwood, MA, USA.
Microbiome. 2020 Jan 24;8(1):7. doi: 10.1186/s40168-020-0786-3.
Anaerobic ammonium oxidation (anammox) is a biological process employed to remove reactive nitrogen from wastewater. While a substantial body of literature describes the performance of anammox bioreactors under various operational conditions and perturbations, few studies have resolved the metabolic roles of their core microbial community members.
Here, we used metagenomics to study the microbial community of a laboratory-scale anammox bioreactor from inoculation, through a performance destabilization event, to robust steady-state performance. Metabolic analyses revealed that nutrient acquisition from the environment is selected for in the anammox community. Dissimilatory nitrate reduction to ammonium (DNRA) was the primary nitrogen removal pathway that competed with anammox. Increased replication of bacteria capable of DNRA led to the out-competition of anammox bacteria, and the loss of the bioreactor's nitrogen removal capacity. These bacteria were highly associated with the anammox bacterium and considered part of the core microbial community.
Our findings highlight the importance of metabolic interdependencies related to nitrogen- and carbon-cycling within anammox bioreactors and the potentially detrimental effects of bacteria that are otherwise considered core microbial community members.
厌氧氨氧化（anammox）是一种从废水中去除活性氮的生物过程。虽然大量文献描述了 anammox 生物反应器在各种操作条件和干扰下的性能，但很少有研究解决其核心微生物群落成员的代谢作用。
在这里，我们使用宏基因组学研究了实验室规模 anammox 生物反应器的微生物群落，从接种开始，经历了性能不稳定事件，到稳定的稳态性能。代谢分析表明，从环境中获取营养物质是 anammox 群落的选择。异化硝酸盐还原为铵（DNRA）是与 anammox 竞争的主要氮去除途径。能够进行 DNRA 的细菌的复制增加导致 anammox 细菌被淘汰，生物反应器的氮去除能力丧失。这些细菌与 anammox 细菌高度相关，被认为是核心微生物群落的一部分。
我们的研究结果强调了 anammox 生物反应器中与氮和碳循环相关的代谢相互依存关系的重要性，以及那些被认为是核心微生物群落成员的细菌可能产生的有害影响。
