RRC ID 51002
著者 Kits KD, Sedlacek CJ, Lebedeva EV, Han P, Bulaev A, Pjevac P, Daebeler A, Romano S, Albertsen M, Stein LY, Daims H, Wagner M.
タイトル Kinetic analysis of a complete nitrifier reveals an oligotrophic lifestyle.
ジャーナル Nature
Abstract Nitrification, the oxidation of ammonia (NH3) via nitrite (NO2-) to nitrate (NO3-), is a key process of the biogeochemical nitrogen cycle. For decades, ammonia and nitrite oxidation were thought to be separately catalysed by ammonia-oxidizing bacteria (AOB) and archaea (AOA), and by nitrite-oxidizing bacteria (NOB). The recent discovery of complete ammonia oxidizers (comammox) in the NOB genus Nitrospira, which alone convert ammonia to nitrate, raised questions about the ecological niches in which comammox Nitrospira successfully compete with canonical nitrifiers. Here we isolate a pure culture of a comammox bacterium, Nitrospira inopinata, and show that it is adapted to slow growth in oligotrophic and dynamic habitats on the basis of a high affinity for ammonia, low maximum rate of ammonia oxidation, high growth yield compared to canonical nitrifiers, and genomic potential for alternative metabolisms. The nitrification kinetics of four AOA from soil and hot springs were determined for comparison. Their surprisingly poor substrate affinities and lower growth yields reveal that, in contrast to earlier assumptions, AOA are not necessarily the most competitive ammonia oxidizers present in strongly oligotrophic environments and that N. inopinata has the highest substrate affinity of all analysed ammonia oxidizer isolates except the marine AOA Nitrosopumilus maritimus SCM1 (ref. 3). These results suggest a role for comammox organisms in nitrification under oligotrophic and dynamic conditions.
巻・号 549(7671)
ページ 269-272
公開日 2017-9-14
DOI 10.1038/nature23679
PII nature23679
PMID 28847001
PMC PMC5600814
MeSH Ammonia / metabolism* Archaea / metabolism Bacteria / genetics Bacteria / growth & development Bacteria / isolation & purification Bacteria / metabolism* Ecosystem* Hot Springs / microbiology Kinetics Nitrates / metabolism Nitrification* Nitrites / metabolism Oxidation-Reduction Soil Microbiology
IF 42.779
引用数 142
リソース情報
一般微生物 JCM 31473 JCM 31988