Aerobic granular sludge (AGS) technology holds great promise of becoming the standard for biological wastewater treatment due to its lower energy consumption, small footprint, and high removal efficiency of nutrients compared to the conventional activated sludge processes. Different-sized aggregates have been shown to harbor a different microbial community composition. The central question is do full-scale AGS wastewater treatment plants (WWTPs) select for core microbial communities across different aggregate sizes and how these selected organisms differ between the different-sized aggregates. This study analyzed samples from nine geographically distributed full-scale AGS WWTPs that consistently perform well in terms of chemical oxygen demand (COD) and nutrient (N and P) removal. The main results showed that site-specific conditions highly influence microbial composition in smaller aggregates (< 1 mm), while larger granules form stable communities independent of WWTP location. Notably, all aggregates contained a small subset of 128–139 core OTUs that were both prevalent and abundant across all sizes. These core OTUs include key functional groups such as fermenters, aerobic heterotrophs, polyphosphate-accumulating organisms (PAOs), glycogen-accumulating organisms (GAOs), and nitrifiers, which play a crucial role in COD and nutrient removal. Additionally, an enrichment pattern was observed, with aerobic heterotrophs dominating in flocs, PAOs in small granules, and GAOs and nitrifiers in large granules. This study offers valuable insights into the core microbiome of different-sized aggregates in full-scale AGS WWTPs and highlights their potential role in overall system performance.

中文翻译：

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全尺寸好氧颗粒污泥厂中不同骨料尺寸的核心微生物群落的表征及其与废水处理性能的相关性


与传统的活性污泥工艺相比，好氧颗粒污泥 （AGS） 技术能耗低、占地面积小、营养物质去除效率高，有望成为生物废水处理的标准。不同大小的聚集体已被证明具有不同的微生物群落组成。核心问题是全规模的 AGS 废水处理厂 （WWTP） 是否选择不同聚集体大小的核心微生物群落，以及这些选定的生物体在不同大小的聚集体之间有何不同。本研究分析了来自九个地理分布的全尺寸 AGS 污水处理厂的样品，这些污水处理厂在化学需氧量 （COD） 和营养物（氮和磷）去除方面始终表现良好。主要结果表明，特定地点的条件高度影响较小聚集体 （< 1 mm） 中的微生物组成，而较大的颗粒形成稳定的群落，而与 WWTP 位置无关。值得注意的是，所有聚集体都包含一小部分 128-139 个核心 OTU，这些 OTU 在所有规模中都普遍且丰富。这些核心 OTU 包括关键功能组，如发酵罐、好氧异养生物、多磷酸盐积累生物 （PAO）、糖原积累生物 （GAO） 和硝化剂，它们在 COD 和营养物质去除中起着至关重要的作用。此外，还观察到富集模式，其中需氧异养生物在絮凝物中占主导地位，PAO 在小颗粒中占主导地位，GAO 和硝化剂在大颗粒中占主导地位。这项研究为全尺寸 AGS 污水处理厂中不同尺寸聚集体的核心微生物组提供了有价值的见解，并强调了它们在整体系统性能中的潜在作用。