Genome-resolved metatranscriptomics unveils distinct microbial functionalities across aggregate sizes in aerobic granular sludge

IF 14 1区环境科学与生态学 Q1 ENVIRONMENTAL SCIENCES

Environmental Science and Ecotechnology Pub Date : 2025-03-25 DOI:10.1016/j.ese.2025.100560

A.Y.A. Mohamed , Laurence Gill , Alejandro Monleon , Mario Pronk , Mark van Loosdrecht , Pascal E. Saikaly , Muhammad Ali

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Abstract

Microbial aggregates of different sizes in aerobic granular sludge (AGS) systems have been shown to exhibit distinct microbial community compositions. However, studies comparing the microbial activities of different-sized aggregates in AGS systems remain limited. In this study, genome-resolved metatranscriptomics was used to investigate microbial activity patterns within differently sized aggregates in a full-scale AGS plant. Our analysis revealed a weak correlation between the relative abundance of metagenome-assembled genomes (MAGs) and their transcriptomic activity, indicating that microbial abundance does not directly correspond to metabolic activity within the system. Flocculent sludge (FL; <0.2 mm) predominantly featured active nitrifiers and fermentative polyphosphate-accumulating organisms (PAOs) from Candidatus Phosphoribacter, while small granules (SG; 0.2–1.0 mm) and large granules (LG; >1.0 mm) hosted more metabolically active PAOs affiliated with Ca. Accumulibacter. Differential gene expression analysis further supported these findings, demonstrating significantly higher expression levels of key phosphorus uptake genes associated with Ca. Accumulibacter in granular sludge (SG and LG) compared to flocculent sludge. Conversely, Ca. Phosphoribacter showed higher expression of these genes in the FL fraction. This study highlights distinct functional roles and metabolic activities of crucial microbial communities depending on aggregate size within AGS systems, offering new insights into optimizing wastewater treatment processes.

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基因组解析的超转录组学揭示了好氧颗粒污泥中不同粒径的微生物功能

在好氧颗粒污泥（AGS）系统中，不同大小的微生物聚集体显示出不同的微生物群落组成。然而，比较AGS系统中不同粒径团聚体微生物活性的研究仍然有限。在这项研究中，基因组解析亚转录组学被用于研究全尺寸AGS植物中不同大小聚集体内的微生物活动模式。我们的分析显示，宏基因组组装基因组（MAGs）的相对丰度与其转录组活性之间存在弱相关性，这表明微生物丰度并不直接对应于系统内的代谢活性。絮凝污泥；0.2 mm)主要是活性硝化菌和来自Candidatus Phosphoribacter的发酵性聚磷微生物（PAOs），而小颗粒(SG；0.2-1.0 mm)和大颗粒(LG；>1.0 mm)含有更多与积累杆菌相关的代谢活性PAOs。差异基因表达分析进一步支持了这些发现，表明与絮凝污泥相比，颗粒污泥（SG和LG）中与Ca. Accumulibacter相关的关键磷吸收基因的表达水平显著更高。相反，Ca. Phosphoribacter在FL片段中表现出较高的这些基因表达。这项研究强调了AGS系统中关键微生物群落的不同功能作用和代谢活动，这取决于它们的聚集大小，为优化废水处理工艺提供了新的见解。

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来源期刊

Environmental Science and Ecotechnology Multiple-

CiteScore

20.40

自引率

6.30%

发文量

审稿时长

18 days

期刊介绍： Environmental Science & Ecotechnology (ESE) is an international, open-access journal publishing original research in environmental science, engineering, ecotechnology, and related fields. Authors publishing in ESE can immediately, permanently, and freely share their work. They have license options and retain copyright. Published by Elsevier, ESE is co-organized by the Chinese Society for Environmental Sciences, Harbin Institute of Technology, and the Chinese Research Academy of Environmental Sciences, under the supervision of the China Association for Science and Technology.