Psychrobacillus glaciei sp. nov., a psychrotolerant species isolated from an Antarctic iceberg

We performed taxonomic studies on a psychrotolerant strain, designated PB01(T), isolated from an Antarctic iceberg. The cells of strain PB01(T) were Gram-stain-positive, strictly aerobic, white-yellow and rod-shaped. The results of 16S rRNA gene sequence analysis revealed that strain PB01(T) was closely related to Psychrobacillus psychrodurans DSM 11713(T) (99.19% similarity), Psychrobacillus psychrotolerans DSM 11706(T) (98.91%) and Psychrobacillus insolitus DSM 5(T) (98.85%). Despite high 165 rRNA, gene sequence similarity, the degrees of DNA-DNA relatedness between strain PB01(T) and its three closest phylogenetic neighbours were 62.4 +/- 7.3% for P psychrodurans DSM 11713(T), 61.1 +/- 5.4% for P psychrotolerans DSM 11706(T) and 56.1 +/- 6.9% for P insolitus DSM 5(T). The predominant cellular fatty acids were anteiso-C-15:0 iso-C-15:0 and C16:1 omega 7c-OH. Menaquinone-8 was the major respiratory quinone, and phosphatidylethanolamine was the major polar lipid. The DNA G+C content of strain PB01(T) calculated from the complete genome sequence was 36.0 mol%. Based on the phenotypic, chemotaxonomic, genomic and phylogenetic data obtained in the present study, we conclude that strain PB01(T) represents a novel species of the genus Psychrobacillus, for which we propose the name Psychrobacillus glaciei sp. nov. The type strain is PB01(T) (=CECT 9792(T)=KCTC 43041(T)).