Aquabacterium lacunae sp. nov., isolated from a freshwater pond

A novel bacterial strain, designated KMB7^T, isolated from a freshwater pond in Taiwan, was characterized using a polyphasic taxonomic approach. Cells were Gram-stain-negative, motile by means of a single polar flagellum, rod-shaped and formed cream colonies. Optimal growth occurred at 25 °C, pH 7, and in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set (92 protein clusters) indicated that strain KMB7^T is affiliated with species in the genus Aquabacterium. The 16S rRNA gene sequence similarity indicated that strain KMB7^T is closely related to species within the genus Aquabacterium (95.2-97.6 % sequence similarity) and is most similar to A. fontiphilum CS-6^T (97.6 %), followed by A. parvum B6^T (97.5 %). The average nucleotide identity and digital DNA-DNA hybridization identity between strain KMB7^T and the closely related strains were 74.6-78.0 % and 19.0-21.2 %, respectively. The major fatty acids of strain KMB7^T were summed feature 3 (C_16 : 1  ω7c and/or C_16 : 1  ω6c), C_18 : 1  ω7c and C_16 : 0. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, diphosphatidylglycerol and four unidentified phospholipids. The sole isoprenoid quinone was ubiquinone-8 (Q-8). Genomic DNA G+C content of strain KMB7^T was 65.4 %. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain KMB7^T should be classified in a novel species of the genus Aquabacterium, for which the name Aquabacterium lacunae sp. nov. is proposed. The type strain is KMB7^T (=BCRC 81156^T=LMG 30924^T=KCTC 62867^T).

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).