Mesorhizobium liriopis sp. nov., isolated from the fermented fruit of Liriope platyphylla a medicinal plant

Abstract

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 62.8mol%. 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). © 2023 The Authors.