Discovery and Genetic Characterization of a New Bacterial Species
A Gram-stain-negative, mobtile, rod-shaped bacterial strain, designated CR28, was isolated from the rhizosphere soil of maize plants and characterized taxonomically using a polyphasic approach. Grows occurred at 15–37 °C (optimum, 28°C), pH 7–9.0 (optimum, pH 8.0), and in 0–1% NaCl (optimum, 0%). Phylogenetic analysis based on 16S rRNA gene sequencing indicated that strain CR28 was related to members of the genus Sphingobium, with the highest sequence identity to Sphingobium xanthum NL9T (97.02%). The major cellular fatty acids (>5% of the total) were C16:0 (12.83%), Summed Feature 3 (C16:1 ?7c and/or C16:1 ?6c, 10.5%)and Summed Feature 8 (C18:1 ?7c and/or C18:1 ?6c, 58.95%). The major isoprenoid quinone was Q-10 and the polar lipid profle contained phosphatidylmonomethylethanolamine, phosphatidylethanolamine  and an unidentified polar lipid . Genome sequencing revealed that had a genome size of 2.88 Mbp with a G +C content of 62.3%. Comparative genomic analyses clearly separated strain CR28 from the known species of the genus Sphingobium based on average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values below the thresholds for species delineation.  Based on genotypic and phenotypic characteristics, strain CR28 represents a novel species of the genus Sphingobium, for which we propose the name Sphingobium maizesoil sp. nov.