A facultative anaerobic and Gram-negative strain, designated RP14T, was isolated from the fruit of Liriope platyphylla fermented for 60 days at 25°C. Strain RP14T showed 98.0 % 16S rRNA similarity to Mesorhizobium huakuii IFO 15243T, but in the phylogenetic tree, Mesorhizobium terrae NIBRBAC000500504T was its closest neighbour. The average nucleotide identity and digital DNA-DNA hybridization values between strain RP14T and 15 genomes of type strains of Mesorhizobium, were 73.8-74.4% and 16.4-20.2 %, respectively, which were lower than the recommended thresholds for species delineation. The strain grew at 25-32°C (optimum, 28°C), at pH 7.0-12.0 (optimum, pH 9.0) and with 0-2% NaCl (optimum, 0 %; w/v). Cells of strain RP14T were catalase-positive, oxidase-negative, rod-shaped and formed yellow-coloured colonies. The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The major fatty acid were C16 : 0, C19 : 0 cyclo ω8c and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The DNA G+C content was 62.8 mol%. Based on polyphasic evidence, we propose Mesorhizobium liriopis sp. nov as a novel species within the genus Mesorhizobium. The type strain is RP14T (=KACC 22720T=TBRC 16341T).
Keywords: Liriope platyphylla; Mesorhizobium liriopis; phylogenomic tree; polyphasic analysis.