Draft Genome Sequence of an Ammonia-Oxidizing Archaeon, “Candidatus Nitrosopumilus koreensis ” AR1, from Marine Sediment

Ammonia-oxidizing archaea (AOA) are ubiquitous in various marine environments and play important roles in the global nitro-gen and carbon cycles. We here present a high-quality draft genome sequence of an ammonia-oxidizing archaeon, “Candidatus Nitrosopumilus koreensis ” AR1, which was found to dominate an ammonia-oxidizing enrichment culture in marine sediment off Svalbard, the Arctic Circle. Despite a significant number of nonoverlapping genes (ca. 30%), similarities of this strain to “Candidatus Nitrosopumilus maritimus ” were revealed by core genes for archaeal ammonia oxidation and carbon fixation, GC content, and extensive synteny conservation. Some lineages of Thaumarchaeota inhabiting various environ-ments, including marine water, freshwater, and hot springs, have been proposed for use as ammonia-oxidizing archaea (AOA) (5, 9, 11). These microbes are capable of using ammonia as an energy source and of performing carbon fixation through the 3-hydroxypropionate/4-hydroxybutyrate pathway (1). But, de-spite their important contributions to the biogeochemical nitro-gen cycle, there remain many unanswered questions on their physiology and ecology. Recently, the genome sequence of “Can-didatus Nitrosopumilus maritimus ” strain SCM1, an ammonia