Flavihumibacter fluminis sp. nov. and Flavihumibacter rivuli sp. nov., isolated from a freshwater stream

Two Gram-stain-positive, aerobic, chemoheterotrophic, non-motile, rod-shaped, and yellow-pigmented bacterial strains, designated IMCC34837 T and IMCC34838 T , were isolated from a freshwater stream. Results of 16S rRNA gene-based phylogenetic analyses showed that strains IMCC34837 T and IMCC34838 T shared 96.3% sequence similarity and were most closely related to Flavihumibacter profundi Chu64-6-1 T (99.6%) and Flavihumibacter cheonanensis WS16 T (96.4%), respectively. Complete whole-genome sequences of strains IMCC34837 T and IMCC34838 T were 5.0 Mbp and 4.3 Mbp of genome size with 44.5% and 47.9% of DNA G + C contents, respectively. Average nucleotide identity (ANI) and digital DNA- DNA hybridization (dDDH) values between the two strains were 70.0% and 17.9%, repectively, revealing that they are independent species. The two strains showed ≤ 75.2% ANI and ≤ 19.3% dDDH values to each closely related species of the genus Flavihumibacter , indicating that the two strains represent each novel species. Major fatty acid constituents of strain IMCC34837 T were iso-C 15:0 , iso-C 15:1 G and anteiso-C 15:0 and those of strain IMCC34838 T were iso-C 15:0 and iso-C 15:1 G. The predominant isoprenoid quinone detected in both strains was menaquinone-7 (MK-7). Major polar lipids of both strains were phosphatidylethanolamine, aminolipids, and glycolipids. Based on the phylogenetic and phenotypic characterization, strains IMCC34837 T and IMCC34838 T were considered to represent two novel species within the genus Flavihumibacter , for which the names Flavihumibacter fluminis sp. nov. and Flavihumibacter rivuli sp. nov. are proposed with IMCC34837 T (= KACC 21752 T = NBRC 115292 T ) and IMCC34838 T (= KACC 21753 T = NBRC 115293 T ) as the type strains, respectively.