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 degrees C (optimum, 37 degrees 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).