Neobacillus rhizosphaerae sp. nov., isolated from the rhizosphere, and reclassification of Bacillus dielmonensis as Neobacillus dielmonensis comb. nov.
Résumé
A Gram-stain-positive, facultative anaerobic endospore-forming bacterium, which originated from roots/rhizosphere of maize ( Zea mays ), was investigated for its taxonomic position. On the basis of 16S rRNA gene sequence similarities, strain JJ-3 T was grouped together with Neobacillus species showing the highest similarities to Neobacillus bataviensis (98.8 %) and the three species Neobacillus dendrensis , Neobacillus soli and Neobacillus cucumis (all 98.6 %). The 16S rRNA gene sequence similarities to the sequences of the type strains of other Neobacillus species were lower than 98.5 %. The average nucleotide identity, average amino acid identity and digital DNA–DNA hybridization values between the JJ-3 T genome assembly and those of the other Neobacillus type strains were <83, <85 and <27 %, respectively. Chemotaxonomic features supported the grouping of the strain to the genus Neobacillus, e.g. the major fatty acids were C 15 : 0 anteiso and C 15 : 0 iso, the polar lipid profile contained the major components diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine, and the major quinone was menaquinone MK-7. Physiological and biochemical test results were slightly different from those of the most closely related species. For this reason, JJ-3 T represents a novel species of the genus Neobacillus , for which we propose the name Neobacillus rhizosphaerae sp. nov., with JJ-3 T (= CIP 111895 T =LMG 32087 T =DSM 111784 T =CCM 9084 T ) as the type strain. We also propose to reclassify Bacillus dielmonensis as Neobacillus dielmonensis comb. nov. based mainly on the results of phylogenomic and conserved signature indel analyses.