Bacillus loiseleuriae sp. nov., isolated from rhizosphere soil from a loiseleuria plant

Abstract

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterium, designated strain FJAT-27997^T, was isolated from the rhizosphere soil of a Loiseleuria plant collected from Sichuan province in China. Growth was observed aerobically between 20 and 35 °C (optimum 30 °C), between 0 and 3.0 % (w/v) NaCl (optimum at 0 %) concentration and pH in the range 6.0-9.0 (optimum at pH 7.0). The cell-wall peptidoglycan contained meso-diaminopimelic acid and the major isoprenoid quinone was menaquinone MK-7. The main fatty acids were iso-C15 : 0, anteiso-C15 : 0, iso-C14 : 0, C16 : 0 and C14 : 0. The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phylogenetic analyses based on 16S rRNA gene sequences showed that isolate FJAT-27997^T was a member of the genus Bacillus and was related most closely to Bacillus simplex DSM 1321^T (97.95 % similarity), followed by Bacillushuizhouensis GSS03^T (97.9 %). The average nucleotide identity value between strain FJAT-27997^T and the most closely related species, B. simplex DSM 1321^T, was 71.60 % (JSpecies), less than the previously proposed cut-off value of 96 % for differentiating species within the genus. The in silico DNA-DNA hybridization values between strain FJAT-27997^T and its most closely related species were <70 %, again indicating they belong to different taxa. The main fatty acids were iso-C15 : 0 and anteiso-C15 : 0. The novel strain could be differentiated from other known Bacillus species on the basis of several phenotypic characters and fatty acid profiles. This taxononomic/genomic study revealed that strain FJAT-27997^T represents a novel Bacillus species, for which the name Bacillus loiseleuriae sp. nov. (type strain FJAT-27997^T =CCTCC AB 2015285^T=DSM 101776^T) is proposed.

Keywords: Bacillus loiseleuriae; genome; rhizosphere soil; taxono-genomics.