Kaistella yananensis sp. nov., a Novel Indoleacetic Acid-Producing Bacterium Isolated from the Root Nodules of Sophora davidii (Franch.) Skeels

A novel endophytic bacterium, designated strain BT6-1-3 T , was isolated from the root nodules of a leguminous shrub named Sophora davidii (Franch.) Skeels, found growing wild in Yan’an, Shaanxi Province, China. Cells were Gram-staining-negative, non-motile, catalase-positive, oxidase-positive, and did not produce H 2 S. Strain BT6-1-3 T grew at 15–40 °C (optimum 30 °C), at pH 6.0–10.0 (optimum pH 9.0), and with 0–1% (w/v) NaCl (optimum 0.5%). The quinone system was menaquinone 6. The major fatty acids present in BT6-1-3 T were iso-C 11:0 , iso-C 15:0 , and C 16:0 . The G+C content of genomic DNA was 39.4 mol% by whole genome sequencing. According to the analysis of 16S rRNA gene sequence, the closest relative was Kaistella montana WG4 (nucleotide identity was 97.6%). The genome of strain BT6-1-3 T was sequenced, and the genome similarity was calculated using average nucleotide identity and genome-to-genome distance analysis with the genomes of other strains of Kaistella . Both strongly supported that the strain BT6-1-3 T belonged to the genus Kaistella as a representative of a new species. Based on phylogenetic analysis, chemotaxonomic data, and physiological and biochemical characteristics, strain BT6-1-3 T represents a new species of the genus Kaistella and is named as Kaistella yananensis sp. nov. Type strain is BT6-1-3 T (= NBRC 115452 T = CGMCC 1.60032 T ).