<i>Dokdonella aquatica</i> sp. nov., isolated from freshwater
Abstract
A Gram-stain-negative, strictly aerobic, non-motile, non-flagellated and rod-shaped bacterium, strain MW10<sup>T</sup>, was isolated from freshwater in South Korea. The strain exhibited catalase-negative and oxidase-positive activities and grew at 15-35 °C (optimum, 25 °C), pH 6.0-9.0 (optimum, 7.0) and in 0-3.0% (w/v) NaCl (optimum, 0%). Ubiquinone-8 was the sole respiratory quinone, and the major cellular fatty acids (>10%) were iso-C<sub>15 : 0</sub>, iso-C<sub>16 : 0</sub> and summed feature 9 (iso-C<sub>17 : 1</sub> <i> ω9</i>c and/or C<sub>16 : 0</sub> 10-methyl). Polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminophospholipid and an unidentified glycolipid. The genome of strain MW10<sup>T</sup> was 4831 kb in size with a DNA G+C content of 69.0 mol%. Strain MW10<sup>T</sup> was most closely related to <i>Dokdonella immobilis</i> LM 2-5<sup>T</sup> and <i>Dokdonella koreensis</i> DS-123<sup>T</sup> with 16S rRNA gene sequence similarities of 97.1% and 96.0%, respectively. Phylogenetic analyses based on 16S rRNA gene and 120 marker protein sequences placed strain MW10<sup>T</sup> within the genus <i>Dokdonella</i> as a distinct lineage. Average nucleotide identity and digital DNA-DNA hybridization values between strain MW10<sup>T</sup> and related type strains were ≤76.6% and ≤21.1%, respectively. Collectively, phylogenetic, genomic, phenotypic and chemotaxonomic evidence support the conclusion that strain MW10<sup>T</sup> represents a novel species of the genus <i>Dokdonella</i>, for which the name <i>Dokdonella aquatica</i> sp. nov. is proposed. The type strain is MW10<sup>T</sup> (=KACC 23687<sup>T</sup>=JCM 36943<sup>T</sup>).