A Gram-stain-negative, aerobic, motile by gliding, and rod-shaped bacterium, designated IMCC34845T, was isolated from a freshwater stream in the Republic of Korea. The results of 16S rRNA gene-based phylogenetic analyses showed that strain IMCC34845T was affiliated with the genus Zwartia and was most closely related to 'Achromobacter panacis' DCY105T (100%) and Zwartia hollandica LF4-65T (98.9%). The whole-genome sequence of strain IMCC34845T was 3.2 Mbp in size with a 51.5% DNA G+C content. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain IMCC34845T and 'Achromobacter panacis' KCTC 42751T were 77.7% and 20.7%, respectively, revealing that they are independent species. Moreover, the strains IMCC34845T and KCTC 42751T exhibited ≤ 72.5% ANI and ≤18.5% dDDH values with closely related species Zwartia hollandica LF4-65T, further supporting that the two strains represent each novel species of the genus. The major respiratory quinone of strain IMCC34845T was ubiquinone-8 (Q-8), and the predominant cellular fatty acids were C16:0 (41.3%) and C17:0 cyclo (34.5%). The major polar lipids of the strain were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified phospholipids, and unidentified aminolipids. Based on the phylogenetic, genomic, physiological, and chemotaxonomic characteristics, strain IMCC34845T was considered to represent a novel species within the genus Zwartia, for which the name Zwartia vadi sp. nov. is proposed. The type of strain is IMCC34845T (=KCTC 92920T = NBRC 114902T). Furthermore, based on the taxonomic data, 'Achromobacter panacis' is proposed to be reclassified as Zwartia panacis comb. nov.
Keywords: GKS98 cluster; Zwartia panacis comb. nov.; Zwartia vadi sp. nov.; polyphasic taxonomy; whole-genome sequencing.