Publications

4492

A bacterial strain named IGB-41T was isolated from a soil sample from an ant hill near Stuttgart, Germany. The strain was Gram-negative, rod-shaped, motile and facultatively anaerobic. Phylogenetic analysis based on 16S rRNA grouped the strain IGB-41T within the class Betaproteobacteria into the family Neisseriaceae together with Silvimonas amylolytica NBRC 103189T, Silvimonas iriomotensis NBRC 103188T and Silvimonas terrae KM-45T as the closest relatives with sequence similarities of 96.7, 96.6 and 96.1 %, respectively. The G+C content of the genomic DNA was determined to be 61.5 mol% and quinone analysis revealed Q-8 as the only detectable quinone. Major cellular fatty acids were identified as C16 : 0, summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c) and C18 : 1ω7c . Strain IGB-41T was unique in harbouring phosphoaminolipids, aminolipids and glycoaminolipids when compared with Silvimonas amylolytica NBRC 103189T in polar lipid analysis. On the basis of the physiological, phenotypic and genotypic characteristics of strain IGB-41T, we suggest that the novel strain should be assigned to a new genus Amantichitinum and novel species Amantichitinum ursilacus. The type species of the genus Amantichitinum is Amantichitinum ursilacus and the type strain is IGB-41T ( = DSM 23761T = CIP 110167T).

ABSTRACT Ammonia-oxidizing archaea (AOA) are ubiquitous in various marine environments and play important roles in the global nitrogen 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, G+C content, and extensive synteny conservation.

ABSTRACT Ammonia-oxidizing archaea (AOA) typically predominate over ammonia-oxidizing bacteria in marine sediments. We herein present the draft genome sequence of an ammonia-oxidizing archaeon, “ Candidatus Nitrosopumilus sediminis” AR2, which was enriched in culture from a marine sediment obtained off Svalbard, within the Arctic Circle. The typical genes involved in archaeal ammonia oxidation and carbon fixation necessary for chemolithoautotrophic growth were observed. Interestingly, the AR2 genome sequence was revealed to possess, uniquely among cultivated AOA from marine environments, a capability for urea utilization.