A novel Gram-stain-negative, facultative aerobic and rod-shaped bacterium, designated as MKL-01T and isolated from the blood of immunocompromised patient, was genotypically and phenotypically characterized. The colonies were found to be creamy yellow and convex. Phylogenetic analysis based on 16S rRNA gene and whole-genome sequences revealed that strain MKL-01T was most closely related to Cupriavidus gilardii LMG 5886T, present within a large cluster in the genus Cupriavidus. The genome sequence of strain MKL-01T showed the highest average nucleotide identity value of 92.1 % and digital DNA-DNA hybridization value of 44.8 % with the closely related species C. gilardii LMG 5886T. The genome size of the isolate was 5 750 268 bp, with a G+C content of 67.87 mol%. The strain could grow at 10-45 °C (optimum, 37-40 °C), in the presence of 0-10 % (w/v) NaCl (optimum, 0.5%) and at pH 6.0-10.0 (optimum, pH 7.0). Strain MKL-01T was positive for catalase and negative for oxidase. The major fatty acids were C16 : 0, summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c and/or C16 : 1 ω6c/C16 : 1 ω7c) and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids and one unidentified polar lipid. Moreover, strain MKL-01T contained ubiquinone Q-8 as the sole respiratory quinone. Based on its molecular, phenotypic and chemotaxonomic properties, strain MKL-01T represents a novel species of the genus Cupriavidus; the name Cupriavidus cauae sp. nov. is proposed for this strain. The type strain is MKL-01T.
Keywords: Cupriavidus cauae; new taxa; phylogenetic analysis; taxonomy.