Nine novel psychrotolerant species of the genus Pedobacter isolated from Arctic soil with potential antioxidant activities

Fifteen isolates of the genus Pedobacter were obtained from Arctic soil samples. All isolates were Gram-stain-negative and rod-shaped. Cells were strictly aerobic, psychrotolerant and grew optimally at 15-20 degrees C. Phylogenetic analysis based on 16S rRNA gene sequences revealed that all the isolated strains formed a lineage within the family Sphingobacteriaceae and clustered as members of the genus Pedobacter. The sole respiratory quinone was MK-7 and the major polar lipid was phosphatidylethanolamine. The major cellular fatty acids were summed feature 3 (iso-C-15:0 2-OH/C-15:1 omega 7c/omega 6c). iso-C-15:0 and iso-C(17:0 )3-OH. The DNA G+C content of the novel strains was 33.9-41.8 mol%. In addition, the average nucleotide identity and in silico DNA-DNA hybridization relatedness values between the novel type strains and phylogenetically related type strains were below the threshold values used for species delineation. Based on genomic, chemotaxonomic, phenotypic, phylogenetic and phylogenomic analyses, the isolated strains represent novel species in the genus Pedobacter, for which the names Pedobacter cryotolerans sp. nov. (type strain AR-2-6(T)=KEMB 9005-717(T)=KACC 19998(T)=NBRC 113826(T)), Pedobacter cryophilus sp. nov. (type strain AR-3-17(T)=KEMB 9005-718(T)=KACC 19999(T)=NBRC 113827(T)), Pedobacter frigiditerrae sp. nov. (type strain RP-1-13(T)=KEMB 9005-720(T)=KACC 21147(T)=NBRC 113829(T)), Pedobacter psychroterrae sp. nov. (type strain RP-1-14(T)=KEMB 9005-721(T)=KACC 21148(T)=NBRC 113830(T)), Pedobacter hiemivivus sp. nov. (type strain RP-3-8(T)=KEMB 9005-724(T)=KACC 21152(T)=NBRC 113833(T)). Pedobacter frigidisoli sp. nov. (type strain RP-3-11(T)= KEMB 9005-725(T)=KACC 21153(T)=NBRC 113927(T)), Pedobacter frigoris sp. nov. (type strain RP-3-15(T)=KEMB 9005-726(T)=KACC 21154(T)=NBRC 113834(T)), Pedobacter psychrodurus sp. nov. (type strain RP3-21(T)=KEMB 9005-728(T)=KACC 21156(T)=NBRC 113835(T)) and Pedobacter polaris sp. nov. (type strain RP-3-22(T)=KEMB 9005-729(T)=KACC 21157(T)=NBRC 113836(T)) are proposed.