Paenibacillus tabacirhizosphaerae sp. nov., isolated from rhizosphere soil of tobacco.

Two Gram-staining positive, aerobic, non-motile, endospore-forming and rod-shaped bacteria, designated strains SI92T and SI8, respectively, were isolated from the rhizosphere soil of tobacco collected from south-western China. Strain SI92T shared the highest 16S rRNA gene similarity to Paenibacillus silvestris (97.9%) and Paenibacillus phytorum (97.9%), and strain SI8 showed the highest 16S rRNA gene similarity with P. phytorum (98.0%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strains SI92T and SI8 clustered with the genus Paenibacillus and formed a distinct subclade. Growth of strains SI92T and SI8 occurred at 15-45 °C, pH 6.0-8.0 (optimum pH 7.0) and with 0-1.0% (wt/vol) NaCl on R2A medium. The respiratory quinones of strains SI92T and SI8 were identified as menaquinone-7. The predominant cellular fatty acids (>10.0%) were identified as anteiso-C15 : 0. The profile of polar lipids contained diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Based on the average nucleotide identity values and the digital DNA-DNA hybridization values with most closely related strains, strains SI92T and SI8 belonged to the same species and represented a novel species of the genus Paenibacillus, for which the name Paenibacillus tabacirhizosphaerae sp. nov. (type strain SI92T=CGMCC 1.19445T=NBRC 115451T) is proposed.