Bacillus acanthi sp. nov., isolated from the rhizosphere soil of a mangrove plant Acanthus ilicifolius

Abstract

A novel bacterium, designated strain L28^T, was isolated from the rhizosphere soil of a mangrove plant in Hong Kong. Cells of strain L28^T are Gram-stain-positive, rod-shaped and endospore-forming. Optimum growth occurs at 37 °C (range, 20-45 °C), 0.5 % (w/v) NaCl (range, 0-5.0 %) and pH 7.5 (range, 6.5-9.0). The major fatty acids are iso-C15 : 0 and C16 : 1ω7c alcohol. The major respiratory quinone is MK-7. The polar lipid profile comprises phospholipid, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol and two unidentified lipids. The 16S rRNA gene sequence analyses indicated that strain L28^T exhibited the highest similarity of 96.7 % to Bacillus asahii MA001^T. The genome size of strain L28^T was 4 063 863 bp with a 36.9 mol% DNA G+C content. Based on the phenotypic and chemotaxonomic properties, along with the phylogenic distinctiveness, it was concluded that this strain represents a novel species of the genus Bacillus, for which the name Bacillusacanthi sp. nov. is proposed. The type strain of this novel species is L28^T (=DSM 104296^T=MCCC 1K03287^T).

Keywords: Acanthus ilicifolius; Bacillus acanthi; mangrove; rhizosphere soil; taxonomy.