Kristensen Jannie Munk, Singleton Caitlin, Clegg Lee-Ann, Petriglieri Francesca, Nielsen Per Halkjaer
Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark.
Front Microbiol. 2021 Apr 22;12:643950. doi: 10.3389/fmicb.2021.643950. eCollection 2021.
Microbial communities in water resource recovery facilities encompass a large diversity of poorly characterized lineages that could have undescribed process-critical functions. Recently, it was shown that taxa belonging to "Acidobacteriota" are abundant in Danish full-scale activated sludge wastewater treatment plants (WWTP), and here we investigated their diversity, distribution, and functional potential. "Acidobacteriota" taxa were identified using a comprehensive full-length 16S rRNA gene reference dataset and amplicon sequencing surveys across 37 WWTPs. Members of this phylum were diverse, belonging to 14 families, eight of which are completely uncharacterized and lack type strains. Several lineages were abundant, with relative abundances of up to 5% of the microbial community. Genome annotation and metabolic reconstruction of 50 high-quality "Acidobacteriota" metagenome-assembled genomes (MAGs) from 19 WWTPs showed high metabolic diversity and potential involvement in nitrogen and phosphorus removal and iron reduction. Fluorescence hybridization (FISH) using newly-designed probes revealed cells with diverse morphologies, predominantly located inside activated sludge flocs. FISH in combination with Raman microspectroscopy revealed ecophysiological traits in probe-defined cells from the families , , and , and families with the placeholder name of midas_f_502, midas_f_973, and midas_f_1548. Members of these lineages had the potential to be polyphosphate-accumulating organisms (PAOs) as intracellular storage was observed for the key compounds polyphosphate and glycogen.
水资源回收设施中的微生物群落包含大量特征描述不足的谱系，这些谱系可能具有尚未描述的对过程至关重要的功能。最近的研究表明，属于“酸杆菌门”的分类群在丹麦的全规模活性污泥废水处理厂（WWTP）中含量丰富，在此我们研究了它们的多样性、分布和功能潜力。使用全面的全长16S rRNA基因参考数据集和对37个污水处理厂的扩增子测序调查来鉴定“酸杆菌门”分类群。该门的成员具有多样性，属于14个科，其中8个科完全没有特征描述且缺乏模式菌株。几个谱系含量丰富，在微生物群落中的相对丰度高达5%。对来自19个污水处理厂的50个高质量“酸杆菌门”宏基因组组装基因组（MAG）进行基因组注释和代谢重建，结果显示其具有高度的代谢多样性，并可能参与氮、磷去除和铁还原过程。使用新设计的探针进行荧光原位杂交（FISH），结果显示细胞形态多样，主要位于活性污泥絮体内部。FISH与拉曼光谱联用揭示了来自科、科和科以及暂命名为midas_f_502、midas_f_973和midas_f_1548科的探针定义细胞的生态生理特征。这些谱系的成员有可能是聚磷积累生物体（PAO），因为观察到关键化合物多磷酸盐和糖原在细胞内储存。
