Rubrivivax albus sp. nov., isolated from a freshwater pond

Strain ICH-3^T, isolated from a freshwater pond in Taiwan 9ROC), was characterized using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set (92 protein clusters) indicated that ICH-3^T is affiliated with the species in the genus Rubrivivax. ICH-3^T was most closely related to Rubrivivax benzoatilyticus JA2^T and Rubrivivax gelatinosus NCIB 8290^T with 97.5 and 97.4 % 16S rRNA gene sequence similarity. The average nucleotide identity and digital DNA-DNA hybridization identity between ICH-3^T and the two closely related strains were 77.3 and 20.9-21.0 %, respectively, indicating that ICH-3^T represents a novel species of the genus Rubrivivax. Cells were Gram-stain-negative, aerobic, non-motile, rod-shaped and formed white colonies. Optimal growth occurred at 30 °C, pH 7.5-8.0 and with 0.5 % NaCl. The major fatty acids (>20 %) of ICH-3^T were summed feature 3 (comprising C_16 : 1ω7c and/or C_16 : 1ω6c) and C_16 : 0. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an uncharacterized aminophospholipid and two uncharacterized phospholipids. The major isoprenoid quinone was Q-8. The genomic DNA G+C content of ICH-3^T was 70.3 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain ICH-3^T should be classified as representing a novel species of the genus Rubrivivax, for which the name Rubrivivax albus sp. nov. is proposed. The type strain is ICH-3^T (=BCRC 81155^T=LMG 30930^T=KCTC 62866^T).