RESUMEN
A Gram-strain-negative, rod-shaped, motile bacterium, designated MIM27T, was isolated from the sand of the Mu Us Desert, PR China. The strain could grow at 4-45 °C (optimum, 37 °C), at pH 6.6-9.0 (optimum, 8.0) and in the presence of 0-3â% (w/v) NaCl (optimum, 0â% in RNA liquid medium). The results of phylogenetic analysis of 16S rRNA gene sequences indicated that the strain represented a member of the genus Rhizobium, with the highest similarity (96.5â%) to Rhizobium pakistanense BN-19T. The results of analysis of the sequences of the nitrogen fixation gene nifH and three housekeeping genes, recA, atpD and glnII, also indicated that MIM27T was most closely related to the species of the genus Rhizobiumwith validly published names but the similarities were low (≤90.7â%). MIM27T did not form nodules on Pisum sativum, Vicia faba, Astragalus sinicus and Phaseolus vulgaris. The major respiratory quinone of MIM27T was Q-10. The genomic DNA G+C content was 59.8 mol%. Major fatty acids of MIM27T were summed feature 8 (C18â:â1ω7c and/or C18â:â1ω6c), C18â:â1ω7c 11-methyl, C16â:â0, summed feature 3 (C16â:â1ω7c and/or C16â:â1ω6c) and summed feature 2 (C12â:â0 aldehyde and/or unknown ECL 10.9525). On the basis of the physiological, chemotaxonomic and phenotypic data, MIM27T is suggested to represent a novel species of the genus Rhizobium, for which the name Rhizobium arenae sp. nov. is proposed. The type strain is MIM27T (=KCTC 52299T=MCCC 1K03215T).