Neorhizobium xiangyangii sp. nov., isolated from a highland barley cultivation soil in Qamdo, Tibet.

A novel Gram-negative, aerobic, rod-shaped and non-nitrogen fixing bacterium named T786 was isolated from a highland barley cultivation soil in Qamdo, Tibet Autonomous Region, PR China. Strain T786 grew at 5-30 ℃ and pH 6.0-10.0 (optimum, 20-25 ℃ and pH 7.0-8.0) with 0-4% (w/v) NaCl (optimum, 0%). The 16S rRNA gene sequences of strain T786 showed the highest similarity to Neorhizobium vignae CCBAU 05176 (98.7%), followed by Neorhizobium alkalisoli CCBAU 01393 (98.5%), Neorhizobium tomejilense T17_20 (98.4%), Neorhizobium huautlense S02 (98.4%), and Neorhizobium galegae ATCC 43677 (98.0%). Phylogenetic analysis based on 16S rRNA genes indicated that strain T786 was a new member of the genus Neorhizobium. The digital DNA-DNA hybridization and average nucleotide identity values between strain T786 and related strains were estimated as 20.2-20.6% and 76.6-80.0%, respectively. The genomic DNA G + C content based on the draft genome sequence was 60.2%. The major cellular fatty acids were Summed feature 8 (C ω7c or C ω6c), C and Summed feature 3 (C ω7c or C ω6c). The polar lipids were diphosphatidyl glycerol, phosphatidyl glycerol, phosphatidyl ethanolamine, phosphatidyl methyl ethanolamine, unidentified phospholipid and unidentified lipids (1-4). The isoprenoid quinone was ubiquinone-10. The DAP and sugar components of cell wall were meso-DAP and ribose, glucose, respectively. Based on phenotypic, phylogenetic, and genotypic data, for which the name Neorhizobium xiangyangii sp. nov. is proposed. The type strain is T786 (= JCM 35100 = CICC 25102).