Genome-centric metagenomic insights into the role of Chloroflexi in anammox, activated sludge and methanogenic reactors

BMC Microbiology

Research

Pía Oyarzúa¹  María Eugenia Suárez-Ojeda¹  Angela Cabezas²  Leandro D. Guerrero³  Leonardo Erijman³  Claudia Etchebehere⁴  Patricia Bovio-Winkler⁴ 

[1]GENOCOV Research Group, Department of Chemical, Biological and Environmental Engineering, Escola d’Enginyeria, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain

[2]Instituto Tecnológico Regional Centro Sur, Universidad Tecnológica, Francisco Antonio Maciel S/N, CP: 97000, Durazno, Uruguay

[3]Instituto de Investigaciones en Ingeniería Genética Y Biología Molecular “Dr Héctor N. Torres” (INGEBI-CONICET), Buenos Aires, Argentina

[4]Microbial Ecology Laboratory, Department of Microbial Biochemistry and Genomic, Biological Research Institute “Clemente Estable”, Avenida Italia 3318, CP: 11600, Montevideo, Uruguay

关键词: Chloroflexi;    Methanogenic reactors;    Activated sludge;    Anammox;    Metagenome assembled genomes;   

DOI  :  10.1186/s12866-023-02765-5

 received in 2022-09-10, accepted in 2023-01-10,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundThe phylum Chloroflexi is highly abundant in a wide variety of wastewater treatment bioreactors. It has been suggested that they play relevant roles in these ecosystems, particularly in degrading carbon compounds and on structuring flocs or granules. Nevertheless, their function is not yet well understood as most species have not been isolated in axenic cultures. Here we used a metagenomic approach to investigate Chloroflexi diversity and their metabolic potential in three environmentally different bioreactors: a methanogenic full-scale reactor, a full-scale activated sludge reactor and a lab scale anammox reactor.ResultsDifferential coverage binning approach was used to assemble the genomes of 17 new Chloroflexi species, two of which are proposed as new Candidatus genus. In addition, we recovered the first representative genome belonging to the genus ‘Ca. Villigracilis’. Even though samples analyzed were collected from bioreactors operating under different environmental conditions, the assembled genomes share several metabolic features: anaerobic metabolism, fermentative pathways and several genes coding for hydrolytic enzymes. Interestingly, genome analysis from the anammox reactor indicated a putative role of Chloroflexi in nitrogen conversion. Genes related to adhesiveness and exopolysaccharides production were also detected. Complementing sequencing analysis, filamentous morphology was detected by Fluorescent in situ hybridization.ConclusionOur results suggest that Chloroflexi participate in organic matter degradation, nitrogen removal and biofilm aggregation, playing different roles according to the environmental conditions.

【 授权许可】

CC BY   
© The Author(s) 2023

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