Psychrobacter pygoscelis sp. nov. isolated from the penguin Pygoscelis papua

Abstract

One slightly beige-white pigmented, Gram-stain-negative, rod-shaped bacterium, strain I-STPP5b^T, was isolated from the trachea of a Gentoo penguin chick individual (Pygoscelin papua) investigated in Fildes Bay, Chilean Antarctic (62° 12' S, 58° 57' W). I-STPP5b^T consists of a 3.4 Mb chromosome with a DNA G+C content of 44.4 mol%. Of the 3056 predicted genes, 1206 were annotated as hypothetical proteins and 51 were tRNAs. Phylogenetic analysis based on nearly full-length 16S rRNA gene sequences showed that the isolate shared a 16S rRNA gene sequence identity to the type strains of Psychrobacter phenylpyruvicus (98.8 %), Psychrobacter arenosus and Psychrobacter pasteurii (both 98.3 %), Psychrobacter piechaudii (98.2 %) and Psychrobacter sanguinis (98.1 %), but 16S rRNA gene sequence similarities to all other Psychrobacter species were ≤98.0 %. Partial gyrB nucleotide and amino acid sequence similarities among strain STPP5b^T and the next related type strains were all below 81.8 and 92.9%, respectively. DNA-DNA hybridisation (DDH) with P. phenylpyruvicus LMG 5372^T, P. arenosus DSM 15389^T and P. sanguinis DSM 23635^T also showed low values (all below 30 %). The main cellular fatty acids of the strain were C_{18 : 1}ω9c and C_{16 : 1}ω7c and/or C_{16 : 1}ω6c. Based on phylogenetic, chemotaxonomic, genomic and phenotypic analyses we propose a new species of the genus Psychrobacter, with the name Psychrobacter pygoscelis sp. nov. and strain I-STPP5b^T (=CIP 111410^T= CCM 8799^T=LMG 30301^T) as type strain.

Keywords: Psychrobacter; Psychrobacter pygoscelis; penguin.