Pedobacter psychrophilus sp nov., isolated from fragmentary rock

Strain P4487A(T) was isolated during investigation of cultivable bacterial populations of environmental materials sampled at James Ross Island, Antarctica. It revealed Gram-stain-negative short rod-shaped cells producing a pink pigment. Phylogenetic analysis based on 16S rRNA gene sequences allocated strain P4487A(T) to the genus Pedobacter but showed that the strain represents a distinct intrageneric phylogenetic lineage clearly separated from remaining Pedobacter species. Phylogenetically, strain P4487A(T) formed a common branch with the Pedobacter arcticus and Pedobacter lignilitoris cluster while the highest value of 94.4% 16S rRNA gene sequence similarity suggested that Pedobacter lentus is the most closely related species. Biochemical and physiological test results enabled the differentiation of strain P4487A(T) from all phylogenetically closely related species. Chemotaxonomic analyses of strain P4487A(T) showed MK-7 as the respiratory menaquinone, sym-homospermidine as the major polyamine, phosphatidylethanolamine and two unidentified lipids as the major polar lipids, presence of sphingolipids, and C-16 : 1 omega 7c/C-16 : 1 omega 6c (summed feature 3), iso-C-15: 0 and iso-C-17 : 0 3-OH as the major fatty acids, all of which corresponded with characteristics of the genus Pedobacter. The results showed that strain P4487A(T) represents a novel species within the genus Pedobacter, for which the name Pedobacter psychrophilus sp. nov. is proposed. The type strain is P4487A(T) (= CCM 8644(T) = LMG 29436(T)).