Oceanobacillus polygoni sp. nov., a facultatively alkaliphile isolated from indigo fermentation fluid

A facultatively alkaliphilic, lactic-acid-producing and halophilic strain, designated SA9(T), was isolated from a fermented Polygonum indigo (Polygonum tinctorium Lour.) liquor sample prepared in a laboratory. The 16S rRNA gene sequence phylogeny suggested that strain SA9(T) was a member of the genus Oceanobacillus with the closest relative being Oceanobacillus profundus KCCM 42318(T) (99.3% 16S rRNA gene sequence similarity). Cells of strain SA9(T) stained Gram-positive and were facultative anaerobic straight rods that were motile by peritrichous flagella. The strain grew between 5 and 48 °C (optimum, 35 °C) and at pH 7-12 (optimum, pH 9). The isoprenoid quinone detected was menaquinone-7 (MK-7) and the DNA G+C content was 40.6 ± 0.9 mol%. The whole-cell fatty acid profile mainly consisted of iso-C(15:0), anteiso-C(15:0), C(16:0) and anteiso-C(17:0). DNA-DNA hybridization with Oceanobacillus profundus DSM 18246(T) revealed a DNA-DNA relatedness value of 23 ± 2%. On the basis of the differences in phenotypic and chemotaxonomic characteristics, and the results of phylogenetic analyses based on 16S rRNA gene sequences and DNA-DNA relatedness data from recognized species of the genus Oceanobacillus, strain SA9(T) merits classification as a representative of a novel species of the genus Oceanobacillus, for which the name Oceanobacillus polygoni sp. nov. is proposed. The type strain is SA9(T) ( =JCM 17252(T) =NCIMB 14684(T)). An emended description of the genus Oceanobacillus is also provided.