Recent studies indicate that ammonia-oxidizing archaea (AOA) may play an important role in nitrogen removal by wastewater treatment plants (WWTPs). However, our knowledge of the mechanisms employed by AOA for growth and survival in full-scale WWTPs is still limited. Here, metagenomic and metatranscriptomic analyses combined with a laboratory cultivation experiment revealed that three active AOAs (WS9, WS192, and WS208) belonging to family Nitrososphaeraceae were active in the deep oxidation ditch (DOD) of a full-scale WWTP treating landfill leachate, which is configured with three continuous aerobic-anoxic (OA) modules with low-intensity aeration (≤ 1.5 mg/L). AOA coexisted with AOB and complete ammonia oxidizers (Comammox), while the ammonia-oxidizing microbial (AOM) community was unexpectedly dominated by the novel AOA strain WS9. The low aeration, long retention time, and relatively high inputs of ammonium and copper might be responsible for the survival of AOA over AOB and Comammox, while the dominance of WS9, specifically may be enhanced by substrate preference and uniquely encoded retention strategies. The urease-negative WS9 is specifically adapted for ammonia acquisition as evidenced by the high expression of an ammonium transporter, whereas two metabolically versatile urease-positive AOA strains (WS192 and WS208) can likely supplement ammonia needs with urea. This study provides important information for the survival and application of the eutrophic Nitrososphaeraceae AOA and advances our understanding of archaea-dominated ammonia oxidation in a full-scale wastewater treatment system.

最近的研究表明，氨氧化古细菌（AOA）可能在废水处理厂（WWTP）的脱氮中起重要作用。但是，我们对AOA在全面污水处理厂中增长和生存所采用的机制的了解仍然有限。在这里，宏基因组学和超转录组学分析与实验室培养实验相结合，揭示了属于亚硝化纲科的三个活性AOA（WS9，WS192和WS208）污水处理厂在污水处理厂渗滤液的深度氧化沟（DOD）中很活跃，垃圾渗滤液由三个连续的低氧曝气（≤1.5 mg / L）的好氧-缺氧（OA）模块组成。AOA与AOB和完全氨氧化剂（Comammox）共存，而氨氧化微生物（AOM）社区出乎意料地由新型AOA菌株WS9主导。低通气量，较长的保留时间以及相对较高的铵和铜输入量可能是AOA优于AOB和Comammox的生存原因，而WS9的优势尤其可以通过底物偏爱和独特编码的保留策略来增强。尿素酶阴性WS9特别适用于氨的吸收，铵转运蛋白的高表达证明了这一点，而两种代谢通用的脲酶阳性AOA菌株（WS192和WS208）可能会补充尿素中的氨需求。该研究为富营养化的生存和应用提供了重要信息。亚硝化细菌AOA并进一步扩大了我们对全规模废水处理系统中以古细菌为主的氨氧化的理解。