sp. nov., a novel member of isolated from activated sludge collected in Hong Kong.

A floc-forming bacterial strain, designated HKLI-1, was isolated from the activated sludge of a municipal sewage treatment plant in Hong Kong SAR, PR China. Cells of this strain were Gram-stain-negative, strictly aerobic, catalase- and oxidase-positive, rod-shaped and motile by means of a single polar flagellum. Growth occurred at 18-37 °C (optimum, 28 °C), pH 5.5-9.0 (optimum, pH 7.5) and with 0-8.0 % (w/v) NaCl (optimum, 1-1.5 %) concentration. The major fatty acids of strain HKLI-1 were C and summed feature 3 (C ω7 and/or C ω6). The polar lipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and three unidentified lipids. The DNA G+C content was 63.5 mol% from whole genomic sequence analysis. Based on the results of 16S rRNA gene sequences analysis, this strain should be assigned to the genus and is closely related to DQS-4 (94.93 % 16S rRNA gene sequence pairwise similarity), MF63 (94.91 %) and SWub3 (94.01 %), but separate from them by large distances in different phylogenetic trees. Based on whole genome analysis, the orthologous average nucleotide identity and DNA-DNA hybridization values against four of the closest relatives were 73.03-74.83 and 17.2-23.0 %, respectively. The phylogenetic, genotypic, phenotypic and chemotaxonomic data demonstrated that strain HKLI-1 could be distinguished from its phylogenetically related species, and that this strain represented a novel species within the genus , for which the name sp. nov. is proposed. The type strain is HKLI-1 (= 72659=CCTCC AB 2019312).