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

Abstract

Abstract The bacterial strain was isolated from the rhizosphere of Elymus dahuricus Turcz. in temperate semi-arid steppe, located in the northern of Inner Mongolia Autonomous Region, China. Strain PJ23T is Gram-stain-negative, aerobic, light-pink, short rod-shaped, and does not form spores. Cell growth could be observed at 4-29 ℃ (optimum, 24 ℃), pH 6.0-8.6 (optimum, 8.0) and in the presence of 0-5 % (w/v) NaCl (optimum, 2.5 %). The major fatty acids of strain PJ23T were Summed feature 8 (C18:1 ω6c and/or C18:1 ω7c) 39.42 %) and C16:0 (9.60 %). The polar lipid profile was composed of phosphatidylcholine, two unidentified glycolipids, one unidentified aminophospholipid, and two other unidentified polar lipids. The sole respiratory quinone was ubiquinone-10. Phylogeny on full length of 16S rRNA gene sequences retrieved from the genomes showed that, the strain was closely related to Terrihabitans soli IZ6T and Flaviflagellibacter deserti SYSU D60017T 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 PJ23T and T. soli IZ6T, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) was 73.39 % and 15.7 %, these values are lower than the proposed and generally accepted species boundaries of dDDH and ANI. Based on phenotypic, chemotaxonomic, and phylogenetic characteristics, strain PJ23T represents a novel species of Terrihabitans, for which the name Terrihabitans rhizophilus sp. nov. is proposed. The type strain is PJ23T (= KCTC 92977T=CGMCC 1.61577T).