A novel Gram-stain negative, facultatively anaerobic, non-spore-forming, motile and rod-shaped bacterium (NS-104T) was isolated from a propanil-contaminated soil in Nanjing, China. Growth occurred at pH 5.0-9.0 (optimum 6.0), 16-37 °C (optimum 30 °C) and in the presence of 0-2.0% (w/v) NaCl (optimum, without NaCl). Strain NS-104T showed high 16S rRNA gene sequence identity to Rhizobium azooxidifex DSM 100211T (96.7%). The phylogenetic analysis of the 16S rRNA gene as well as the housekeeping genes recA, atpD and glnA demonstrated that strain NS-104T belongs to the genus Rhizobium. Strain NS-104T did not form nodules on six different legumes, and the nodD, nodC and nifH genes were neither amplified by PCR nor found in the draft genome of strain NS-104T. The sole respiratory quinone was ubiquinone Q-10. The polar lipid profile included the major amounts phosphatidylmonomethylethanolamine, phosphatidylglycerol and moderate amounts of phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol and unidentified aminolipids. The major cellular fatty acids were C18:1ω7c (39.6%), C19:0 cyclo ω8c (29.8%) and C16:0 (11.5%). The G + C content of strain NS-104T was 61.9 mol%. Strain NS-104T therefore represents a new species, for which the name Rhizobium album sp. nov. is proposed, with the type strain NS-104T (= KCTC 62327T = CCTCC AB 2017250T).
Keywords: 16S rRNA gene; Gram-stain negative; Rhizobium album sp. nov.; The housekeeping genes.