Pseudoalteromonas neustonica sp nov., isolated from the sea surface microlayer of the Ross Sea (Antarctica), and emended description of the genus Pseudoalteromonas

A Gram-stain-negative, facultatively anaerobic, rod-shaped and motile strain, designated PAMC 28425(T), was isolated from a sea surface microlayer sample from the Ross Sea, Antarctica. Analysis of the 16S rRNA gene sequence of strain PAMC 28425(T) showed an affiliation with the genus Pseudoalteromonas. Phylogenetic analyses revealed that strain PAMC 28425(T) formed a clade with Pseudoalteromonas prydzensis MB8-11(T) and Pseudoalteromonas mariniglutinosa KMM 3635(T) with 16S rRNA gene sequence similarities of 98.3-98.6 %. Genomic relatedness analyses based on the average nucleotide identity and the genome-to-genome distance showed that strain PAMC 28425(T) is clearly distinguished from the phylogenetically close relatives. Cells of strain PAMC 28425(T) grew optimally at 25 degrees C and pH 7.5-8.5 in the presence of 1.0-3.0% (w/v) sea salts. The major cellular fatty acids (>10 %) were C-16 : 1 omega 6c and/or C-16 : 1 omega 7c, C-16 : 0, and C-18 : 1 omega 6c and/or C-18 : 1 omega 7c. The genomic DNA G+C content was 39.7 mol%. On the basis of the phylogenetic, genomic, chemotaxonomic and phenotypic data presented, we propose the name Pseudoalteromonas neustonica sp. nov. with the type strain PAMC 28425(T) (=KCCM 43187(T) =JCM 31286(T)).