Re-examination of the taxonomic status of the Antarctic Pseudomonas syringae Lz4W isolate and proposal to rename it as a novel species Pseudomonas cryophila sp. nov.

A taxonomic re-evaluation of the Antarctic psychrotrophic bacterium Pseudomonas syringae Lz4W was performed in the light of its available genome sequence and due to a revision in the key phenotypic characteristics that are in conflict with the "syringae" group of Pseudomonads. A 16S rRNA gene sequence based phylogenetic analysis suggested that Lz4WT strain belongs to "fragi" cluster of Pseudomonas species, with closest similarity (99.72%) to the type strain P. deceptionensis M1T. However, in silico analysis of the Lz4W genome sequence using SpecI (species identification tools), ANI (average nucleotide identity), and GBDP (Genome Blast Distance phylogeny) methods suggest that Lz4WT strain cannot be delineated with any of the type strains of "fragi" cluster of species. Based on predictive low DNA-DNA hybridization value (<29.9%) and differences in phenotypic features with the related species we suggest that Lz4WT is a novel species under the Pseudomonas genus, and we propose that the strain be named as Pseudomonas cryophila sp. nov. The type strain is Lz4WT (=CFBP 8403T =KCTC 42933T =LMG 29591T =MTCC 673T).