A new species of bacterial predator (PP10T) was isolated from a biocrust sample taken from near Potter Cove, King George Island, Antarctica (62°14'15.62″S 58°43'15.65″W). The Bdellovibrio and like organism was vibrio-shaped and employed a single polar flagellum for motility. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that this isolate clustered within the genus Bacteriovorax in the family Bacteriovoracaceae. The 16S rRNA gene sequence similarities between isolate PP10T and the type strain (Bacteriovorax stolpii DSM 12778T) were only 97.14%. The draft genome of PP10T has a size of 4.243 Mbps, with 4148 genes and a G+C content of 38.49%. While the optimal temperature for its growth was 25 °C, PP10T was active at 4 °C, classifying it as psychrotolerant. The results of genetic and physiological tests indicated phenotypic differentiation of strain PP10T from the type strain Bx. stolpii DSM 12778T. Based on physiological and phylogenetic analyses, as well as the prey spectrum, isolate PP10 represents a novel species within the genus Bacteriovorax, for which the name Bacteriovorax antarcticus sp. nov. is proposed. The type strain is PP10T (= KCTC 8097T = DSM 116241T).
Keywords: Antarctica; Bacteriovorax; King George Island; biocrust; predatory bacteria.