Neptunomonas antarctica sp nov., isolated from marine sediment

A Gram-negative, motile, oxidase- and catalase-positive and facultatively aerobic bacterium, designated Sw3-22(T), was isolated from marine sediment of the Nella Fjord, Antarctica. Strain S322(T) reduced nitrate to nitrite and grew at pH 6.0-8.0, at 4-25 degrees C and with 0.5-5% (w/v) NaCl. It contained Q-8 as the only respiratory quinone and summed feature 3 (C-16:1 omega 7c and/or iso-C-15:0 2-OH, C-16:0 and C-18:1 omega 7c as the major cellular fatty acids. The genomic DNA G+C content was 45.6 mol%. Phylogenetic analyses of 16S rRNA gene sequences showed that strain S3-22(T) was affiliated with the genus Neptunomonas, with 97.1% sequence similarity to Neptunomonas japonica JAMM 0745(T) and 94.8% to Neptunomonas naphthovorans NAG-2N126(T), the type strains of the only two recognized Neptunomonas species. DNA DNA relatedness between strain S3-22T and N. japonica JCM 145951 was 20.4%. Strain 53-22(T) could be distinguished from the type strains of Neptunomonas species by several phenotypic properties. Based on the evidence from our polyphasic study, strain S3-22(T) represents a novel Neptunomonas species, for which the name Neptunomonas antarctica sp. nov. is proposed. The type strain is S3-22(T) (=CCTCC AB 209086(T) =KACC 14056(T)).