Elizabethkingia argenteiflava sp. nov., isolated from the pod of soybean, Glycine max

Abstract

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).