Responses of a microbial community in the completely autotrophic nitrogen removal over nitrite (CANON) process, which was shocked by a pH of 11.0 for 12 h, were investigated. During the recovery phase, the performance, anaerobic ammonia oxidation (anammox) activity, microbial community, and correlation of bacteria as well as the influencing factors were evaluated synchronously. The performance of the CANON process deteriorated rapidly with a nitrogen removal rate (NRR) of 0.13 kg·m^-3·d^-1, and Firmicutes, spore-forming bacteria, were the dominant phyla after alkaline shock. However, it could self-restore within 107 days after undergoing four stages, at which Planctomycetes became dominant with a relative abundance of 64.62%. Network analysis showed that anammox bacteria (Candidatus Jettenia, Kuenenia, and Brocadia) were positively related to some functional bacteria such as Nitrosomonas, SM1A02, and Calorithrix. Canonical correspondence analysis presented a strong correlation between the microbial community and influencing factors during the recovery phase. With the increase of nitrogen loading rate, the decrease of free nitrous acid and the synergistic effects, heme c content, specific anammox activity (SAA), NRR, and the abundance of dominant genus increased correspondingly. The increase of heme c content regulates the quorum sensing system, promotes the secretion of extracellular polymeric substances, and further improves SAA, NRR, and the relative abundance of the dominant genus. This study highlights some implications for the recovery of the CANON reactor after being exposed to an alkaline shock.

中文翻译：

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CANON反应器中的微生物群落对极端碱性冲击的响应和适应。

研究了微生物群落在亚硝酸盐（CANON）过程中完全自养脱氮过程中的响应，该过程受到11.0的pH冲击12 h。在恢复阶段，同步评估其性能，厌氧氨氧化（anammox）活性，微生物群落，细菌的相关性以及影响因素。CANON工艺的性能迅速下降，脱氮率（NRR）为0.13 kg·m ^-3 ·d ^-1，并且碱冲击后的菌毛是形成孢子的细菌。但是，它可以在经历四个阶段后的107天内自动恢复，在该阶段中，扁平菌占主导地位，相对丰度为64.62％。网络分析表明，厌氧细菌（暂定Jettenia，Kuenenia和Brocadia）呈正相关的一些功能性细菌如亚硝化，SM1A02和Calorithrix。典型的对应分析表明，在恢复阶段，微生物群落与影响因素之间存在很强的相关性。随着氮负荷率的增加，游离亚硝酸的减少以及血红素c含量，特定厌氧氨氧化活性（SAA），NRR和优势菌属的丰度产生协同效应。血红素c含量的增加调节群体感应系统，促进细胞外聚合物的分泌，并进一步改善SAA，NRR和优势属的相对丰度。这项研究突出了碱暴露后对CANON反应器回收的一些影响。