Nutrient availability significantly impacts microbial biosynthesis, cell growth, and cell cycle progression. In this study, a full-scale plug-flow partial nitritation/anammox (PN/A) system was used to investigate variations in the microbial community structure in both immobilized carriers and flocs, as well as a gradual decrease in nutrient availability from upstream to downstream. We found that reduced ammonia nitrogen (from 150.4 to 30.6 mg/L) and organic carbon (from 415.7 to 342.8 mg/L) availability significantly lowered microbial diversity and altered microbial communities in biofilms other than flocs from upstream to downstream. The abundance of all anammox bacteria increased by 1.97 times, from 3.25 × 10¹⁰ to 6.40 × 10¹⁰ copies per gram of wet sludge, in the biofilm core microbiome. Furthermore, from upstream to downstream, taxa with lower ribosomal RNA operon copy numbers were consistently enriched in both biofilm and floc communities, indicating that slow-growing microorganisms are more likely to be enriched in low-nutrient environments. Rare taxa with a relative abundance of less than 0.1% exhibited unique metabolic functions, including amino acid, carbohydrate, cofactor, and vitamin metabolisms, which was inferred by PICRUST2 and persisted across the nutrient gradient in both the biofilm and floc communities. Despite their low abundance, they may play important roles in mediating the stability and function of the PN/A system. Overall, the results demonstrate the impact of a naturally formed ammonia nitrogen and organic carbon gradient in a full-scale plug-flow PN/A installation on nutrient availability and its effects on microbial diversity, community composition, and microbial interactions, which expands our fundamental understanding of this energy-efficient and promising biotechnology for treating high-strength ammonium wastewater.

营养物质的可用性显着影响微生物的生物合成、细胞生长和细胞周期进程。在这项研究中，采用全尺寸推流部分亚硝化/厌氧氨氧化（PN/A）系统来研究固定化载体和絮凝体中微生物群落结构的变化，以及从上游到下游养分有效性的逐渐降低。下游。我们发现，氨氮（从 150.4 至 30.6 mg/L）和有机碳（从 415.7 至 342.8 mg/L）可用性的降低显着降低了微生物多样性，并从上游到下游改变了除絮凝体以外的生物膜中的微生物群落。生物膜核心微生物组中，所有厌氧氨氧化细菌的丰度增加了 1.97 倍，从每克湿污泥 3.25 × 10 ¹⁰拷贝增加到 6.40 × 10 ^10拷贝。此外，从上游到下游，核糖体RNA操纵子拷贝数较低的类群在生物膜和絮凝物群落中持续富集，表明生长缓慢的微生物更有可能在低营养环境中富集。相对丰度低于 0.1% 的稀有类群表现出独特的代谢功能，包括氨基酸、碳水化合物、辅因子和维生素代谢，这是由 PICRUST2 推断的，并且在生物膜和絮凝群落的营养梯度中持续存在。尽管它们的丰度较低，但它们可能在调节 PN/A 系统的稳定性和功能中发挥重要作用。总体而言，结果证明了全尺寸推流式 PN/A 装置中自然形成的氨氮和有机碳梯度对养分可用性的影响及其对微生物多样性、群落组成和微生物相互作用的影响，这扩展了我们的基础研究了解这种用于处理高浓度氨废水的节能且有前景的生物技术。