Bacillus miscanthi sp. Nov., a alkaliphilic bacterium from the rhizosphere of Miscanthus sacchariflorus

A novel bacterial strain, designated AK13^T (=KACC 21401^T=DSM 109981^T), was isolated from the rhizosphere of Miscanthus sacchariflorus. Strain AK13^T was found to be an aerobic, Gram-stain–positive, endospore-forming and rod-shaped bacterium. It formed yellow circular colonies with smooth convex surfaces. The genomic DNA G+C content of strain AK13^T was estimated to be 40 mol%. Phylogenetic analysis based on 16S rRNA gene sequence similarity showed that this strain was most closely related to Bacillus lehensis MLB2^T (99.4 %), Bacillus oshimensis K11^T (98.8 %) and Bacillus patagoniensis PAT 05^T (96.6 %). The average nucleotide identity values between strain AK13^T and B. lehensis MLB2^T, B. oshimensis K11^T and B. patagoniensis PAT 05^T were 90.93, 91.05 and 71.87 %, respectively, with the digital DNA–DNA hybridization values of 42.7, 42.6 and 18.8 %, respec-tively. Cells grew at 5–40 °C (optimum, 28–35 °C), pH 6.5–13 (optimum, pH 8–9) and in the presence of 0–13.0 % (w/v) NaCl (optimum, 1 %). The cell wall of strain AK13^T contained meso-diaminopimelic acid, and the major isoprenoid quinone was MK-7. Results of fatty acid methyl ester analysis revealed that iso-C_{15: 0} was the predominant cellular fatty acid. Two-dimensional thin-layer chromatography analysis indicated that the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phos-phatidylethanolamine and glycolipid. The genotypic and phenotypic characteristics suggested that strain AK13^T represented a novel species of the genus Bacillus, and thus the name Bacillus miscanthi sp. nov. is proposed.