Pedobacter rhizosphaerae sp. nov. and Pedobacter soli sp. nov., isolated from rhizosphere soil of Chinese cabbage (Brassica campestris)

Abstract

Two bacterial strains, 01-96(T) and 15-51(T), isolated from rhizosphere soil of Chinese cabbage (Brassica campestris) were characterized by using a polyphasic approach. 16S rRNA gene sequence analysis showed that strain 01-96(T) was phylogenetically related most closely to Pedobacter suwonensis 15-52(T) and Pedobacter roseus CL-GP80(T) (96.7 and 96.7% similarity, respectively), and strain 15-51(T) to Pedobacter borealis G-1(T) and P. suwonensis 15-52(T) (97.2 and 97.1%, respectively). However, levels of DNA-DNA relatedness between strain 15-51(T) and P. borealis KACC 14287(T) and P. suwonensis KACC 11317(T) were low (<50%). The G+C content of the genomic DNA was 37.8 mol% for strain 01-96(T) and 38.6 mol% for strain 15-51(T). The major fatty acids of the two strains were iso-C(17:0) 3-OH, iso-C(15:0) and summed feature 3 (iso-C(15:0) 2-OH and/or C(16:1)ω7c). The results of DNA-DNA hybridization and phenotypic data showed that strains 01-96(T) and 15-51(T) could be distinguished from their closest phylogenetic relatives, and that these strains represented two novel species of the genus Pedobacter, for which the names Pedobacter rhizosphaerae sp. nov. (type strain 01-96(T) =KACC 14938(T) =NBRC 107690(T)) and Pedobacter soli sp. nov. (type strain 15-51(T) =KACC 14939(T) =NBRC 107691(T)) are proposed.