Terrihabitans rhizophilus sp. nov., isolated from the rhizosphere soil of plant in temperate semi-arid steppe.

A bacterial strain PJ23 was isolated from the rhizosphere soil of Elymus dahuricus Turcz. sampled from a temperate semi-arid steppe in the northern of Inner Mongolia Autonomous Region, China. The strain is Gram-stain-negative, aerobic, light-pink, short rod-shaped, and non-spore-forming. Cell growth could be observed at 4-29℃ (optimal at 24℃), pH 6.0-8.6 (optimal at 8.0) and in the presence of 0-5.0% (w/v) NaCl (optimal at 2.5%). The major cellular fatty acids of strain PJ23 were Summed feature 8 (C and/or C) (39.42%) and C (9.60%). The polar lipids were phosphatidylcholine, two unidentified glycolipids, one unidentified aminophospholipid, and two other unidentified polar lipids. The major respiratory quinone was ubiquinone-10. Phylogeny analysis based on 16S rRNA gene sequences retrieved from the genomes showed that, the strain was closely related to the species Terrihabitans soli IZ6 and Flaviflagellibacter deserti SYSU D60017, with the sequence similarities of 96.79% and 96.15%, respectively. The G + C content was 65.23 mol% calculated on draft genome sequencing. Between the strains PJ23 and Terrihabitans soli IZ6, the average nucleotide identity (ANI), amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) was 73.39%,71.12% and 15.7%, these values were lower than the proposed and generally accepted species boundaries of ANI, AAI and dDDH, respectively. Based on phenotypic, chemotaxonomic, and phylogenetic characteristics, strain PJ23 represents a novel species of Terrihabitans, for which the name Terrihabitans rhizophilus sp. nov. is proposed. The type strain is PJ23 (= KCTC 92977 = CGMCC 1.61577).