Low diversity and microdiversity of comammox bacteria in wastewater systems suggest specific adaptations within the Ca. Nitrospira nitrosa cluster.

Autor: Cotto I; Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, United States., Vilardi KJ; Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, United States., Huo L; School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, United States., Fogarty EC; Committee on Microbiology, The University of Chicago, Chicago, IL, United States., Khunjar W; Hazen and Sawyer, Inc., New York, NY, United States., Wilson C; Hampton Roads Sanitation District, Norfolk, VA, United States., De Clippeleir H; DC Water, Washington DC, United States., Gilmore K; Department of Civil and Environmental Engineering, Bucknell University, Lewisburg, PA, United States., Bailey E; City of Raleigh Public Utilities, Raleigh, NC, United States., Lücker S; Department of Microbiology, RIBES, Radboud University, Nijmegen, the Netherlands., Pinto AJ; School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, United States. Electronic address: ameet.pinto@ce.gatech.edu.
Jazyk: angličtina
Zdroj: Water research [Water Res] 2023 Feb 01; Vol. 229, pp. 119497. Date of Electronic Publication: 2022 Dec 14.
DOI: 10.1016/j.watres.2022.119497
Abstrakt: Studies have found Ca. Nitrospira nitrosa-like bacteria to be the principal or sole comammox bacteria in nitrogen removal systems for wastewater treatment. In contrast, multiple populations of strict ammonia and nitrite oxidizers co-exist in similar systems. This apparent lack of diversity is surprising and could impact the feasibility of leveraging comammox bacteria for nitrogen removal. We used full-length 16S rRNA gene sequencing and genome-resolved metagenomics to compare the species-level diversity of comammox bacteria with that of strict nitrifiers in full-scale wastewater treatment systems and assess whether this comparison is consistent or diverged at the strain-level. Full-length 16S rRNA gene sequencing indicated that Nitrosomonas-like bacteria exhibited higher species-level diversity in comparison with other nitrifying bacteria, while the strain-level diversity (also called microdiversity) of most Nitrospira-like bacteria were higher than Nitrosomonas-like bacteria with few exceptions (one Nitrospira lineage II population). Comammox bacterial metagenome assembled genomes (MAGs) were associated with Ca. Nitrospira nitrosa. The average amino acid identity between principal comammox bacterial MAGs (93% ± 3) across systems was significantly higher than that of the Nitrosomonas-like ammonia oxidizers (73% ± 8), the Nitrospira_A-like nitrite oxidizer (85% ± 4), and the Nitrospira_D-like nitrite oxidizer (83% ± 1). This demonstrated the low species-level diversity of comammox bacteria compared with strict nitrifiers and further suggests that the same comammox population was detected in all systems. Comammox bacteria (Nitrospira lineage II), Nitrosomonas and, Nitrospira_D (Nitrospira lineage II) MAGs were significantly less microdiverse than the Nitrospira_A (lineage I) MAGs. Interestingly, strain-resolved analysis also indicates that different nitrogen removal systems harbor different comammox bacterial strains within the Ca. Nitrospira nitrosa cluster. These results suggest that comammox bacteria associated with Ca. Nitrospira nitrosa have low species- and strain-level diversity in nitrogen removal systems and may thus harbor specific adaptations to the wastewater ecosystem.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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