Rheinheimera fenheensis sp. nov., Isolated from Fenhe River Basin, China.

Three Gram-stain-negative, aerobic, rod-shaped bacterial strains, FR7-31, FR7-34 and HH7-4, were isolated from sediment samples of the Fenhe River basin, China. The 16S rRNA gene sequence analysis revealed that strain FR7-31 shares 99.7% and 99.4% similarities with strains FR7-34 and HH7-4, respectively. These three strains exhibited high sequence similarities to Rheinheimera nanhaiensis E407-8 (98.6-98.9%), Rheinheimera aquimaris SW-353 (98.4-98.6%), and Rheinheimera pleomorphica PKS7 (98.3-98.8%), and less than 98.0% similarity with other Rheinheimera type strains. Taxonomic placement based on phylogenetic analyses of 16S rRNA gene sequences and 1480 single-copy orthologous clusters, placed these strains within the genus Rheinheimera. Strain FR7-31 contained C and summed features 3 (Cω7c/Cω6c and/or iso-C 2-OH) as its major fatty acids. The predominant polar lipids included phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid and three unidentified lipids. The genome of strain FR7-31 was 3.63 Mb in length with 50.5% G + C content. Strain FR7-31 shared 98.1% average nucleotide identity (ANI) and 80.8-81.7% digital DNA-DNA hybridization (dDDH) values with strains FR7-34 and HH7-4, indicating they represent the same species. Additionally, ANI and dDDH values between strain FR7-31 and other Rheinheimera type strains with publicly available genomes were below 89.4% and 37.6%, respectively. Distinct phenotypic and genotypic characteristics differentiate strains FR7-31, FR7-34 or HH7-4 from other Rheinheimera species. Thus, type strain FR7-31 (= MCCC 1K07536 = KCTC 92239) along with strains FR7-34 (= MCCC 1K07537 = KCTC 92240) and HH7-4 (= MCCC 1K07538 = KCTC 92241) represent a novel Rheinheimera species, in which the name Rheinheimera fenheensis, is proposed.