Oceanobacillus alkalisoli sp. nov., an alkaliphilic bacterium isolated from saline-alkaline soil.

Abstract

Two alkaliphilic strains, designated APA_J-2 (6-2)T and APA_J-5 (13-2), were isolated from saline-alkali soil sampled in Jilin Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the two strains APA_J-2 (6-2)T and APA_J-5(13–2) were closely related to members of the genus Oceanobacillus , and had the highest sequence similarity to Oceanobacillus indicireducens JCM 17251T (96.8 and 96.9 %, respectively). The 16S rRNA gene sequence similarity between the two novel isolates was 99.6 %, indicating that they were similar species. Cells were Gram-stain-positive, aerobic, motile and rod-shaped. The strains grew at 15–45 °C (optimum, 37 °C), pH 8.0–11.0. (optimum, pH 9) and with 0–10 % (w/v) NaCl (optimum, 5 %). The strains contained menaquinone-7 as the respiratory quinone and anteiso-C15 : 0 as the predominant cellular fatty acid. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol. The genomic DNA G+C content was 40.0 mol%. The average nucleotide identity (ANI), amino acid identity (AAI) and digital DNA–DNA hybridization (dDDH) values of strain APA_J-2 (6-2)T with O. indicireducens JCM 17251T were 85.5, 87.9 and 30.7 %, respectively. The ANI, AAI and dDDH values of strain APA_J-5 (13-2) with O. indicireducens JCM 17251T were 85.7, 87.7 and 30.8 %, respectively. Based on the phylogenetic, phenotypic, biochemical, chemotaxonomic and genome data, strains APA_J-2 (6-2)T and APA_J-5 (13-2) represent a novel species of the genus Oceanobacillus , for which the name Oceanobacillus alkalisoli sp. nov. is proposed. The type strain is APA_J-2 (6-2)T (=KCTC 43253T=GDMCC 1.2242T).