Soybean pods, separated and enclosed from the outside environment, are considered a suitable place to find new microbes. A Gram-stain-negative, aerobic bacterium, bacterial strain (YB22T) was isolated from the pod of Glycine max (soybean) collected from a rural area in Republic of Korea and characterized by using polyphasic taxonomy. Cells of the strain were rod-shaped (approximately 0.4-0.6 µm wide and 4.0-5.0 µm long), non-flagellated and formed silver-yellow colonies. Cells grew at 25-35 °C (optimum, 28-30 °C), at pH 5.0-9.0 (optimum, pH 7.0) and with 0-2.0% NaCl (optimum, 0 % NaCl). 16S rRNA gene sequencing showed that strain YB22T was phylogenetically closest to the genus Elizabethkingia, and showed highest similarities to Elizabethkingia occulta G4070T (96.7 %), Elizabethkingia meningoseptica ATCC 13253T (96.7 %), Elizabethkingia miricola DSM 14571T (96.6 %), Elizabethkingia bruuniana G0146T (96.5 %), Elizabethkingia ursingii G4122T (96.4 %) and Elizabethkingia anophelis R26T (96.2 %). Average amino acid identity values between strain YB22T and other taxa in the genus Elizabethkingia were all above the threshold range of genus determination. Average nucleotide identity and digital DNA-DNA hybridization values between strain YB22T and other phylogenetic relatives were all found to be below the threshold range for species determination. The respiratory quinone of strain YB22T was menaquinone 6 (MK-6) and the predominant cellular fatty acids were iso-C15 : 0 (47.8 %) and iso-C17 : 0 3-OH (18.5 %). The major polar lipids were phosphatidylethanolamine, four unidentified aminolipids and three unidentified polar lipids. The phylogenetic analysis and physiological and biochemical data showed that strain YB22T should represent a novel species in the genus Elizabethkingia, for which the name Elizabethkingia argenteiflava sp. nov. is proposed. The type strain for this novel species is YB22T (=KCCM 43263T=JCM 32097T).
Keywords: Elizabethkingia; average amino acid identity; average nucleotide identity; polyphasic taxonomy; soybean; whole genome.