Anaerobic ammonium oxidation (anammox) is a biological process often applied in wastewater treatment plants for nitrogen removal from highly concentrated side-stream effluents from anaerobic digesters. However, they are vulnerable to process instability prompted by operational shocks and microbial community imbalances, resulting in lengthy recovery times. These issues are further compounded by a lack of understanding of how sustained press disturbances influence the microbial ecology of the system. Here we investigate the response and recovery of an anammox membrane bioreactor to a solids retention time (SRT)-induced reactor crash using 16S rRNA gene and shotgun metagenomic sequencing. We observed a strong selection of bacterial groups based on reproduction strategies, with the Orders Rhodospirillales and Sphingobacteriales increasing from 1.0% and 11.9% prior to the crash to 31.9% and 18.1% during the crash respectively. The Orders Brocadiales and Anaerolineales decreased from 17.3% and 28.3% to 7.3% and 1.4% over the same time period, respectively. Metagenomic and metatranscriptomic analyses revealed differential crash responses in metabolically distinct groups of bacteria, with increased expression of genes for extracellular carbohydrate active enzymes, peptidases and membrane transporters. Following the crash, the reactor recovered to its prior state of nitrogen removal performance and pathway analysis demonstrated increased expression of genes related to exopolysaccharide biosynthesis and quorum sensing during the reactor recovery period. This study highlights the effects of reactor perturbations on microbial community dynamics in anammox bioreactors and provides insight into potential recovery mechanisms from severe disturbance.

中文翻译：

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生活史策略决定了对厌氧氨氧化生物反应器中 SRT 驱动碰撞的反应


厌氧铵态氮氧化 （anammox） 是一种生物工艺，通常用于废水处理厂，用于从厌氧消化池的高浓度侧流出物中脱氮。然而，它们容易受到操作冲击和微生物群落失衡引起的工艺不稳定的影响，从而导致恢复时间过长。由于缺乏对持续印刷干扰如何影响系统微生物生态学的理解，这些问题进一步加剧。在这里，我们使用 16S rRNA 基因和鸟枪法宏基因组测序研究了厌氧氨氧化膜生物反应器对固体保留时间 （SRT） 诱导的反应器崩溃的响应和回收。我们观察到基于繁殖策略的细菌群选择很多，红螺菌目和鞘氨醇菌目从崩溃前的 1.0% 和 11.9% 分别增加到崩溃期间的 31.9% 和 18.1%。同期，Brocadiales 和 Anaerolineales 目分别从 17.3% 和 28.3% 下降到 7.3% 和 1.4%。宏基因组学和宏转录组学分析揭示了代谢不同的细菌群中的不同碰撞反应，细胞外碳水化合物活性酶、肽酶和膜转运蛋白基因的表达增加。坠毁后，反应器恢复到之前的脱氮性能状态，通路分析表明，在反应器恢复期间，与胞外多糖生物合成和群体感应相关的基因表达增加。本研究强调了反应器扰动对厌氧氨氧化生物反应器中微生物群落动力学的影响，并提供了对严重干扰的潜在恢复机制的见解。