A strictly aerobic, Gram-stain-negative, rod-shaped, yellow, non-spore-forming bacterial strain, designated P-25T, was isolated from soil collected in Yantai, Shandong Province, PR China. The temperature, pH and NaCl concentration ranges for the growth of strain P-25T were 10-37 °C (optimum, 28-30 °C), pH 6.0-9.0 (optimum, pH 7.5-8.0) and 0-4 % (w/v) (optimum, 1 % w/v), respectively. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain P-25T was most closely related to Pedobacter xixiisoli S27T (98.1 % 16S rRNA gene sequence similarity), followed by Pedobacter chitinilyticus CM134L-2T (97.2 %) and Pedobacter ureilyticus THG-T11T (97.1 %). The genomic DNA G+C content of strain P-25T based on its draft genome sequence was 38.1 %. MK-7 was the major respiratory quinone, and iso-C15 : 0, C16 : 1ω7c and/or C16 : 1ω6c (summed feature 3) and iso-C17 : 0 3-OH were the major fatty acids. The major polar lipids were phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified phospholipid, two unidentified lipids, five unidentified aminolipids and two unidentified glycolipids. Average nucleotide identity values for the draft genomes between strain P-25T and strains S27T, CM134L-2T and THG-T11T were 81.8, 77.6 and 81.2 %, respectively, and the digital DNA-DNA hybridization (dDDH) values were 30.0, 19.2 and 27.6 %, respectively. Based on their phylogenetic and phenotypic characteristics, chemotaxonomic data, and dDDH results, strain P-25T is considered to represent a novel species of the genus Pedobacter, for which the name Pedobacter helvus sp. nov. is proposed; the type strain is strain P-25T (KCTC 62821T=CCTCC AB 2018185T).
Keywords: Pedobacter helvus sp. nov.; farmland soil; polyphasic taxonomy.