Abstract
A betaproteobacterial chemolithotrophic ammonia-oxidizing bacterium designated APG5(T) was isolated from supralittoral sand of the Edmonds City Beach, WA, USA. Growth was observed at 10-35 degrees C (optimum, 30 degrees C), pH 5-9 (optimum, pH 8) and ammonia concentrations as high as 100 mM (optimum, 1-30 mM NH4Cl). The strain grows optimally in a freshwater medium but tolerates up to 400 mM NaCl. It is most closely related to 'Nitrosomonas ureae' (96.7% 16S rRNA and 92.4% amoA sequence identity). The 3.75-Mbp of AGP5(T) draft genome contained a single rRNA operon and all necessary tRNA genes and has the lowest G+C content (43.5%) when compared to the previously reported genomes of reference strains in cluster 6 Nitrosomonas. Based on an average nucleotide identity of 82% with its closest relative ('N. ureae' Nm10(T)) and the suggested species boundary of 95-96%, a new species Nitrosomonas supralitoralis sp. nov. is proposed. The type strain of Nitrosomonas supralitoralis is APG5(T) (= NCIMB 14870(T) = ATCC TSD-116(T)).
