Uncultured Nitrospina-like species are major nitrite oxidizing bacteria in oxygen minimum zones

无法培养的硝化刺菌属类似菌种是低氧区的主要亚硝酸氧化细菌

10.1038/s41396-019-0443-7

2019-05-22, Article

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Abstract:收起Oxygen minimum zones (OMZs) are marine regions where O2 is undetectable at intermediate depths. Within OMZs, the oxygen-depleted zone (ODZ) induces anaerobic microbial processes that lead to fixed nitrogen loss via denitrification and anammox. Surprisingly, nitrite oxidation is also detected in ODZs, although all known marine nitrite oxidizers (mainly Nitrospina) are aerobes. We used metagenomic binning to construct metagenome-assembled genomes (MAGs) of nitrite oxidizers from OMZs. These MAGs represent two novel Nitrospina-like species, both of which differed from all known Nitrospina species, including cultured species and published MAGs. Relative abundances of different Nitrospina genotypes in OMZ and non-OMZ seawaters were estimated by mapping metagenomic reads to newly constructed MAGs and published high-quality genomes of members from the Nitrospinae phylum. The two novel species were present in all major OMZs and were more abundant inside ODZs, which is consistent with the detection of higher nitrite oxidation rates in ODZs than in oxic seawaters and suggests novel adaptations to anoxic environments. The detection of a large number of unclassified nitrite oxidoreductase genes in the dataset implies that the phylogenetic diversity of nitrite oxidizers is greater than previously thought.

First Authors:Xin Sun

Correspondence Authors:Xin Sun

All Authors:Xin Sun,Linnea F M Kop,Maggie C Y Lau,Jeroen Frank,Amal Jayakumar,Sebastian Lücker,Bess B Ward