Ramlibacter terrae sp. nov. and Ramlibacter montanisoli sp. nov., Isolated from Soil

Two gram-negative, catalase-positive, strictly aerobic, and white colony-forming bacteria, strains H242(T) and B156(T), were isolated from soil in South Korea. Cells of strain H242(T) were oxidase-positive and non-motile short rods, while those of strain B156(T) were oxidase-negative and long non-motile rods. Ubiquinone-8 was identified as the sole isoprenoid quinone in both strains. C-16:0, cyclo-C-17:0, and summed feature 3 (C-16:1 omega 7c and/or C-16:1 omega 6c) and phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol were identified in both strains as the major cellular fatty acids and polar lipids, respectively. The DNA G+C contents of strains H242(T) and B156(T) were 69.4 mol% and 69.3 mol%, respectively. Phylogenetic analyses based on 16S rRNA and 92 concatenated core gene sequences revealed that strains H242(T) and B156(T) formed distinct phylogenic lineages from other Ramlibacter type strains. The DNA-DNA hybridization (DDH) value between strains H242(T) and B156(T) was 24.6%. Strains H242(T) and B156(T) were most closely related to Ramlibacter ginsenosidimutans BXN5-27(T) and Ramlibacter monticola G-3-2(T) with 98.4% and 98.6% 16S rRNA gene sequence similarities, respectively. Digital DDH values between strain H242(T) and R. ginsenosidimutans and between strain B156(T) and R. monticola were 23.5% and 26.1%, respectively. Phenotypic, chemotaxonomic, and molecular analyses indicated that strains H242(T) and B156(T) represent two novel species of the genus Ramlibacter, for which the names Ramlibacter terrae sp. nov. and Ramlibacter montanisoli sp. nov., respectively, are proposed. The type strains of R. terrae and R. montanisoli are H242(T) (=KACC 21667(T)=JCM 33922(T)) and B156(T) (=KACC 21665(T)=JCM 33920(T)), respectively.

Automated summary

Two novel species of the genus Ramlibacter, named Ramlibacter terrae sp. nov. and Ramlibacter montanisoli sp. nov., were isolated from soil in South Korea. These strains have distinct cellular characteristics and DNA composition, forming phylogenic lineages different from other Ramlibacter type strains.