title: Comammox in drinking water systems.
abstract: The discovery of complete ammonia oxidizer (comammox) has fundamentally upended our perception of the global nitrogen cycle. Here, we reported four metagenome assembled genomes (MAGs) of comammox Nitrospira that were retrieved from metagenome datasets of tap water in Singapore (SG-bin1 and SG-bin2), Hainan province, China (HN-bin3) and Stanford, CA, USA (ST-bin4). Genes of phylogenetically distinct ammonia monooxygenase subunit A (amoA) and hydroxylamine dehydrogenase (hao) were identified in these four MAGs. Phylogenetic analysis based on ribosomal proteins, AmoA, hao and nitrite oxidoreductase (subunits nxrA and nxrB) sequences indicated their close relationships with published comammox Nitrospira. Canonical ammonia-oxidizing microbes (AOM) were also identified in the three tap water samples, ammonia-oxidizing bacteria (AOB) in Singapore's and Stanford's samples and ammonia-oxidizing archaea (AOA) in Hainan's sample. The comammox amoA-like sequences were also detected from some other drinking water systems, and even outnumbered the AOA and AOB amoA-like sequences. The findings of MAGs and the occurrences of AOM in different drinking water systems provided a significant clue that comammox are widely distributed in drinking water systems.
authors.affiliation: Environmental Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Environmental Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Liping
authors.initials: L
authors.lastname: Ma
authors.affiliation: Environmental Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Mao
authors.affiliation: Environmental Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Xiaotao
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Environmental Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Yu
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Environmental Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Ke
authors.initials: K
authors.lastname: Yu
authors.affiliation: Environmental Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.affiliation: Environmental Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong. Electronic address: zhangt@hku.hk.
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001105:Archaea / Q000235:genetics; D001419:Bacteria / Q000378:metabolism; D060766:Drinking Water / Q000378:metabolism*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics; D010802:Phylogeny
chemical_list: D060766:Drinking Water; D000641:Ammonia; D010088:Oxidoreductases
keywords: Comammox; Drinking water systems; Metagenomics