gen. nov., sp. nov., a novel member of family , isolated from a water purification facility with supplement of starch as a carbon source.

During a survey of microbial communities in the influent (ambient water) and effluent of a water purification facility with aeration and supplement of starch as carbon source, a novel bacterial strain, designated SZ9, was isolated from the effluent sample. Colonies of strain SZ9 were small (approximately 0.5-1.0 mm in diameter), creamy-white, circular, smooth, translucent and convex. Cells were facultative anaerobic, motile by means of a single polar flagellum, rod-shaped, multiplied by binary fission, Gram-stain-negative, oxidase-positive and catalase-negative. Growth occurred at 10-40 °C (optimum, 28 °C) and pH 5.5-8.0 (optimum, pH 7.5). The range of NaCl concentration for growth was 0-1.0 % (w/v), with an optimum of 0-0.5 % (w/v). Phylogenetic analysis based on 16S rRNA gene sequences suggested that strain SZ9 formed a lineage within the family of the class and showed the highest 16S rRNA gene sequence similarities to TH1-2 (92.44%), followed by SYSU XM001 (89.61 %), DRW22-8 (89.49 %) and WM6 (89.49%). The predominant fatty acids (>10 % of the total fatty acids) of strain SZ9 was summed feature 3 (comprising C 6 and/or C 7), summed feature 8 (C 6 and/or C 7) and C. The sole respiratory quinone was ubiquinone-10, and the major polar lipids were phosphatidylcholine and two unidentified glycolipids. The whole genome of strain SZ9 was 2 842 140 bp in size, including 2769 protein-coding genes, 37 tRNA genes and two rRNA genes, and the genomic G+C content was 41.4 mol%. The orthologous average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between strain SZ9 and other genera within the family were 64.50-66.62 %, 46.96-54.17 % and 27.70-31.70 %, respectively. Therefore, based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, the isolated strain SZ9 could be distinguished from other genera, suggesting that it represents a novel species of a novel genus in the family , for which the name gen. nov., sp. nov is proposed. The type strain is SZ9 (=CCTCC AB2021029=KCTC 82788).