Habitat distribution of the genus in continental waters and the description of sp. nov., sp. nov. and sp. nov.

The genus belongs to the family (order , phylum ) and harbours aerobic chemoheterotrophic bacteria. Members of this genus were isolated from various aquatic habitats, and our analysis based on global amplicon sequencing data revealed that their relative abundance can reach up to 5-10 % of the bacterioplankton in soda lakes and pans. Although a remarkable fraction of the most frequent genotypes that we identified from continental aquatic habitats is still uncultured, five new alkaliphilic strains were characterized in detail in this study, which were isolated from three different soda lakes and pans of the Carpathian Basin (Hungary). Cells of all strains were Gram-stain-negative, obligate aerobic, rod-shaped, non-motile and non-spore-forming. The isolates were oxidase- and catalase-positive, red-coloured, but did not contain flexirubin-type pigments; they formed bright red colonies that were circular, smooth and convex. Their major isoprenoid quinone was MK-7 and the predominant fatty acids were iso-C, iso-C 3-OH and summed feature 3 containing C 6 and/or C 7. The polar lipid profiles contained phosphatidylethanolamine, an unidentified aminophospholipid, an unidentified glycolipid, and several unidentified lipids and aminolipids. Based on whole-genome sequences, the DNA G+C content was 37.0, 37.1 and 37.8 mol % for strains R4-6, DMA-N-10a and U6F3, respectively. The distinction of three new species was confirmed by genomic comparison. Orthologous average nucleotide identity (<85.4 %) and digital DNA-DNA hybridization values (<38.9 %) supported phenotypic, chemotaxonomic and 16S rRNA gene sequence data and, therefore, the following three novel species are proposed: sp. nov. (represented by strains R4-6=DSM 111903=JCM 34281=UCCCB122 and S4-10), sp. nov. (DMA-N-10a=DSM 107340=JCM 34280=UCCCB121) and sp. nov. (U6F3=DSM 111904=JCM 34282=UCCCB123 and U6F1). Emended descriptions of species , , , and are also presented.